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The extent to which the neural systems underlying semantic processes degrade with advanced age remains unresolved, which motivated the current study of neural activation on functional magnetic resonance imaging (fMRI) during semantic judgments of associated vs. unassociated, semantic vs. rhyme, and abstract vs. rhyme word pairs. Thirty-eight older adults, 55–85 years of age, performed semantic association decision tasks in a mixed event-related block fMRI paradigm involving binary judgments as to whether word pairs were related (i.e., semantically associated). As hypothesized, significantly greater activation was evident during processing of associated (vs. unassociated) word pairs in cortical areas implicated in semantic processing, including the angular gyrus, temporal cortex, and inferior frontal cortex. Cortical areas showed greater activation to unassociated (vs. associated) word pairs, primarily within a large occipital cluster. Greater activation was evident in cortical areas when response to semantic vs. phonemic word pairs. Contrasting activation during abstract vs. concrete semantic processing revealed areas of co-activation to both semantic classes, and areas that had greater response to either abstract or concrete word pairs. Neural activation across conditions did not vary as a function of greater age, indicating only minimal age-associated perturbation in neural activation during semantic processing. Therefore, the response of the semantic hubs, semantic control, and secondary association areas appear to be largely preserved with advanced age among older adults exhibiting successful cognitive aging. These findings may provide a useful clinical contrast if compared to activation among adults experiencing cognitive decline due Alzheimer's, frontal-temporal dementia, and other neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Practice is acknowledged as a crucial facilitator for musicians to achieve performance excellence. Despite the rich literature on incorporating musical imagery intentionally to improve one's practice efficacy, limitations remain in the understanding of voluntary musical imagery (VMI) in the context of musical practice. Therefore, our aims in this review are threefold. First, we enriched the interpretation of VMI in the context of music practice through the lens of embodied cognition. Second, we integrated neuroscientific findings to elucidate how the deliberate use of musical imagery parallels physical practice in effectiveness. Third, we synthesize work on the application of VMI in enhancing musical learning from both theoretical and practical perspectives. By providing an integrated overview of voluntary musical imagery, we highlight gaps in the literature and encourage further research on (1) the impact of embodied experiences on VMI formation, (2) optimal imagery content and ratio combination to establish a personalized intervention protocol for more effective musical pedagogy, and (3) on physiological measures to access VMI effectiveness. Additionally, we highlight the crucial implications of VMI for researchers, performers, and music educators. [ABSTRACT FROM AUTHOR]

Practice is acknowledged as a crucial facilitator for musicians to achieve performance excellence. Despite the rich literature on incorporating musical imagery intentionally to improve one’s practice efficacy, limitations remain in the understanding of voluntary musical imagery (VMI) in the context of musical practice. Therefore, our aims in this review are threefold. First, we enriched the interpretation of VMI in the context of music practice through the lens of embodied cognition. Second, we integrated neuroscientific findings to elucidate how the deliberate use of musical imagery parallels physical practice in effectiveness. Third, we synthesize work on the application of VMI in enhancing musical learning from both theoretical and practical perspectives. By providing an integrated overview of voluntary musical imagery, we highlight gaps in the literature and encourage further research on (1) the impact of embodied experiences on VMI formation, (2) optimal imagery content and ratio combination to establish a personalized intervention protocol for more effective musical pedagogy, and (3) on physiological measures to access VMI effectiveness. Additionally, we highlight the crucial implications of VMI for researchers, performers, and music educators.

This study explores the effectiveness of functional near-infrared spectroscopy (fNIRS) as an implicit measurement tool for evaluating sweetness intensity and affective value. Thirty-two participants tasted sucrose solutions at concentrations of 0.15 M, 0.3 M, and 0.6 M, while both their neural responses were recorded with a 24-channel fNIRS system and their self-reported assessments of sweetness intensity and affective value were collected. The neural fNIRS data were converted into oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) concentrations using the modified Beer–Lambert Law, and analyzed through univariate activation analysis and multivariable decoding analysis to identify neural activation patterns associated with sweetness perception. The results showed significant activation in the dorsolateral prefrontal cortex (dlPFC) and orbitofrontal cortex (OFC) in response to varying levels of sweetness intensity and affective value, with channels 8, 10, 12, 13, 14, 15, and 17 consistently activated across all sucrose concentrations. As sweetness concentration increased from 0.15 M to 0.6 M, the number of significantly activated channels rose from seven to eleven, indicating stronger and more widespread neural responses corresponding to higher sweetness intensity. The multivariable decoding analysis further demonstrated the capability of fNIRS in accurately distinguishing positive affective responses, with up to 72.1% accuracy. The moderate positive correlation between explicit self-reports and implicit fNIRS data regarding sweetness intensity further supports the validity of fNIRS as a reliable tool for assessing taste perception. This study highlights the potential of fNIRS in sensory neuroscience, demonstrating its effectiveness in capturing the neural mechanisms underlying sweet taste perception.

Context: The etiology of patellofemoral pain has remained elusive, potentially due to an incomplete understanding of how pain, motor control, and kinesiophobia disrupt central nervous system functioning. Objective: To directly evaluate brain activity during experimental knee pain and its relationship to kinesiophobia in patients with patellofemoral pain. Design: Cross-sectional. Methods: Young females clinically diagnosed with patellofemoral pain (n = 14; 14.4 [3.3] y; body mass index = 22.4 [3.8]; height = 1.61 [0.1 ] m; body mass = 58.4 [12.7] kg). A modified Clarke test (experimental pain condition with noxious induction via patella pressure and quadriceps contraction) was administered to the nondominant knee (to minimize limb dominance confounds) of patients during brain functional magnetic resonance imaging (fMRI) acquisition. Patients also completed a quadriceps contraction without application of external pressure (control contraction). Kinesiophobia was measured using the Tampa Scale of Kinesiophobia. The fMRI analyses assessed brain activation during the modified Clarke test and control contraction and assessed relationships between task-induced brain activity and kinesiophobia. Standard processing for neuroimaging and appropriate cluster-wise statistical thresholds to determine significance were applied to the 1MRI data (z > 3.1, P < .05). Results: The fMRI revealed widespread neural activation in the frontal, parietal, and occipital lobes, and cerebellum during the modified Clarke test (all zs > 4.4, all Ps < .04), whereas neural activation was localized primarily to frontal and cerebellar regions during the control contraction test (all zs > 4.4, all Ps < .01). Greater kinesiophobia was positively associated with greater activity in the cerebello-frontal network for the modified Clarke test (all zs > 5.0, all Ps < .01), but no relationships between kinesiophobia and brain activity were observed for the control contraction test (all zs < 3.1, all Ps > .05). Conclusions: Our novel experimental knee pain condition was associated with alterations in central nociceptive processing. These findings may provide novel complementary pathways for targeted restoration of patient function. [ABSTRACT FROM AUTHOR]

Several methods are in use to record and analyze neuronal activation, each with specific advantages and challenges. New developments like the decomposition of high-density surface electromyography (HDsEMG) have enabled novel insights into discharge characteristics noninvasively in laboratory settings but face certain challenges to be applied in sports physiology in a broader scope. Several challenges can be accounted for by methodological considerations, others require further technological developments to allow this technology to be used in more applied settings. This paper aims to describe the developments of surface electromyography and identify the challenges and perspectives of HDsEMG in the context of an application in sports physiology. We further discuss methodological possibilities to overcome some of the challenges to investigate specific research questions and identify areas that require further advancements. [ABSTRACT FROM AUTHOR]

Neuromuscular Plantar Flexor Performance of Sprinters versus Physically Active Individuals. Med. Sci. Sports Exerc., Vol. 56, No. 1, pp. 82-91, 2024. Introduction: Comparison of the neuromuscular performance of different athlete types may give insight into the in vivo variability of these measures and their underpinning mechanisms. The study aims to compare the neuromuscular function of the plantar flexors of sprinters and physically active individuals to assess any differences in explosive force performance. Methods: Neuromuscular performance of a group of sprinters (highly trained/national level, n = 12; elite/international level, n = 2) and physically active individuals (n = 14) were assessed during involuntary, explosive, and maximum voluntary isometric plantar flexions, across different muscle–tendon unit (MTU) lengths (10° plantarflexion, 0° (anatomical zero/neutral), and 10° dorsiflexion). Plantarflexion rate of torque development (RTD) was measured in three 50-ms time windows from their onset. The synchronous activation of the plantar flexor agonist muscles was calculated as the time difference between 1) the first and last muscle onset and 2) the onsets of the two gastrocnemii muscles. Muscle size and MTU stiffness were assessed using sonograms of the medial gastrocnemius and myotendinous junction. Results: Sprinters exhibited greater involuntary RTD across time points (0–50 ms, 50–100 ms) and MTU lengths. In addition, sprinters demonstrated greater early phase voluntary RTD (0–50 ms, 50–100 ms) across MTU lengths. Sprinters also demonstrated greater late-phase RTD (100–150 ms), and relative maximal voluntary torque at the DF angle only. The sprinters demonstrated a more synchronous activation of the gastrocnemii muscles. There were no observable differences in muscle size and MTU stiffness between groups. Conclusions: These findings suggest sprint-specific training could be a contributing factor toward improved explosive performance of the plantar flexors, particularly in the early phase of muscular contraction, evidenced by the greater explosive torque producing capabilities of sprinters. [ABSTRACT FROM AUTHOR]

Emerging scientific evidence indicates that frequent digital technology use has a significant impact-both negative and positive-on brain function and behavior. Potential harmful effects of extensive screen time and technology use include heightened attention-deficit symptoms, impaired emotional and social intelligence, technology addiction, social isolation, impaired brain development, and disrupted sleep. However, various apps, videogames, and other online tools may benefit brain health. Functional imaging scans show that internet-naive older adults who learn to search online show significant increases in brain neural activity during simulated internet searches. Certain computer programs and videogames may improve memory, multitasking skills, fluid intelligence, and other cognitive abilities. Some apps and digital tools offer mental health interventions providing self-management, monitoring, skills training, and other interventions that may improve mood and behavior. Additional research on the positive and negative brain health effects of technology is needed to elucidate mechanisms and underlying causal relationships.
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According to their nature, rewarding stimuli are classified as primary (e.g., food, sex) and secondary (e.g., money) rewards. Neuroimaging studies have provided valuable insights in neural reward processing and its various aspects including reward expectation, outcome and prediction error encoding. However, there is only limited evidence of whether the two different types of rewards are processed in common or distinct brain areas, in particular when considering the different functions of reward processing. We analyzed a sample of 42 healthy, male participants using task-based functional magnetic resonance imaging (fMRI) during a variant of the monetary incentive delay task. We aimed to investigate the effects of three different rewarding stimuli—two primary (food and sex) and one secondary (money)—on the various functions of reward processing. To provide a thorough description, we focused on 12 brain regions of interest and utilized the Bayes factor bound (BFB) to express stimulus-related main effects and pairwise differences at different levels of evidence, ranging from weak to decisive. Our results revealed a dominance of sexually charged stimuli in engaging the brain's reward structures for all investigated aspects of reward processing. Nevertheless, the ventral tegmental area, amygdala, ventral caudate, ventromedial prefrontal cortex, subgenual anterior cingulate cortex, and lateral orbitofrontal cortex were activated by both primary and secondary reward outcomes. For other reward processing functions, i.e., reward expectation and the prediction error, effects of the different stimuli were weaker, and effects from one reward type cannot easily be generalized to the other.

Depression and social anxiety are common disorders that have a profound impact on social functioning. The need for studying the neural substrates of social interactions in mental disorders using interactive tasks has been emphasized. The field of neuroeconomics, which combines neuroscience techniques and behavioral economics multiplayer tasks such as the Ultimatum Game (UG), can contribute in this direction. We assessed emotions, behavior, and Event‐Related Potentials in participants with depression and/or social anxiety symptoms (MD/SA, n = 63, 57 females) and healthy controls (n = 72, 67 females), while they played the UG. In this task, participants received fair, mid‐value, and unfair offers from other players. Mixed linear models were implemented to assess trial level changes in neural activity. The MD/SA group reported higher levels of sadness in response to mid‐value and unfair offers compared to controls. In controls, the Medial Frontal Negativity associated with fair offers increased over time, while this dynamic was not observed in the MD/SA group. The MD/SA group showed a decreased P3/LPP in all offers, compared to controls. These results indicate an enhanced negative emotional response to unfairness in the MD/SA group. Neural results reveal a blunted response over time to positive social stimuli in the MD/SA group. Moreover, between‐group differences in P3/LPP may relate to a reduced saliency of offers and/or to a reduced availability of resources for processing incoming stimuli in the MD/SA group. Findings may shed light into the neural substrates of social difficulties in these disorders. It is crucial to study the neural substrates of social interactions in mental health using interactive tasks that immerse the participant in a social context. The Ultimatum Game was used to assess ERPs to fair, mid‐value, and unfair offers from others in depressed and/or socially anxious volunteers. We found blunted neural responses over time to fair offers as well as reduced availability of resources for processing incoming social stimuli in depression and social anxiety. [ABSTRACT FROM AUTHOR]

Children with epilepsy can experience significant cognitive dysfunction that can lead to academic underachievement. Traditionally believed to be primarily due to the effects of factors such as the chronicity of epilepsy, medication effects, or the location of the primary epileptogenic lesion;, recent evidence has indicated that disruption of cognition-specific distributed neural networks may play a significant role as well. Specifically, over the last decade, researchers have begun to characterize the mechanisms underlying disrupted cognitive substrates by evaluating neural network abnormalities observed during specific cognitive tasks, using task-based functional magnetic resonance imaging (fMRI). This targeted review assesses the current literature investigating the relationship between neural network abnormalities and cognitive deficits in pediatric epilepsy. The findings indicate that there are indeed neural network abnormalities associated with deficits in executive function, language, processing speed, and memory. Overall, cognitive dysfunction in pediatric epilepsy is associated with a decrease in neural network activation/deactivation as well as increased recruitment of brain regions not typically related to the specific cognitive task under investigation. The research to date has focused primarily on children with focal epilepsy syndromes with small sample sizes and differing research protocols. More extensive research in children with a wider representation of epilepsy syndromes (including generalized epilepsy syndromes) is necessary to fully understand these relationships and begin to identify underlying cognitive phenotypes that may account for the variability observed across children with epilepsy. Furthermore, more uniformity in fMRI protocols and neuropsychological tasks would be ideal to advance this literature.

• Conduct driving simulator experiments and fMRI experiments to investigate driving behavior changes and drivers' neural activation modifications subjected to decorated interior walls. • Explain the association between driver behavior and brain activation at a macro level. • This study verifies the feasibility of transmitting information in the form of decorated interior walls to the driver was verified, and reveals the potential information regulation mechanism and crucial factors. This study reports on the driving behavior changes and drivers' neural activation modifications as a response to information stimulation in the form of tunnel-decorated interior walls during simulated driving, revealing the underlying mechanisms of action. 35 participants performed a simulation experiment consisting of a driving simulator experiment (29 participants) and an fMRI experiment (30 participants, including 24 participants duplicated across both experiments). The study protocol consisted of two scenarios (a baseline and a decorated interior wall scenario) in which participants performed the baseline scenario to initiate the first testing. The driving behavior data (drivers' attention and mental workload, longitudinal speed regulation, and lateral control stability) and drivers' neural activation data were recorded and analyzed for the whole experimental session. This study used repeated measures generalized linear models (GLM) and Statistical Parameter Mapping (SPM12) platforms for statistical analysis. The results indicate that: 1) a decorated interior wall does affect drivers' attention and mental workload significantly, and drivers' boredom, psychological burden, and crash risk are reduced under the information stimulus. The color and element complexity of decorated interior tunnel walls constitute crucial factors in this information regulation mechanism, strongly related to driver distraction; 2) Under the influence of tunnel interior walls decorated with longitudinal strips, the driver's spatial perception and imagination are significantly improved, reducing anxiety and fear associated with hitting the interior walls. The lateral stability of vehicle operation is improved; however, compared with vertical stripes decoration, the effect of the tunnel interior wall decorated with horizontal stripes on drivers' speed regulation is not great. [ABSTRACT FROM AUTHOR]

Cooperation is a universal human principle reflecting working with others to achieve common goals. The rational decision-making model contends that cooperation is the best strategy for maximizing benefits in an iterative prisoner's dilemma. However, the motivations for cooperation (or betrayal) are complex and diverse, and often include fairness reflections. In this study, we used functional magnetic resonance imaging to study underlying neural differences in brain regions related to fairness when people interact with an opponent who tend to cooperate or betray, at different decision-making stages. Results based on 40 university students (25 women) indicate that experiences of cooperation or betrayal affect people's fairness perception. Distinct neural activities occur in expectation, decision, and outcome phases of decisions. In the expectation phase, those in the cooperative condition exhibited increased activation in the anterior cingulate gyrus, medial superior frontal gyrus, and caudate nucleus compared to those in the uncooperative condition. During the decision phase, those in the cooperative condition showed greater activation in the middle frontal gyrus, caudate nucleus/frontal insula, inferior frontal gyrus, and cingulate gyrus compared to those in the uncooperative condition. In the outcome feedback phase, the caudate nucleus, insula, cingulate gyrus, and inferior frontal gyrus of the orbit were more active in the uncooperative condition than in the cooperative condition. Results also showed a significant correlation between caudate activity and the perception of fairness when expecting uncooperative conditions. [ABSTRACT FROM AUTHOR]

Objective:Neural substrates of loss of control (LOC) eating are undercharacterized. We aimed to model intermittent access to food to elicit disinhibited eating in youth undergoing neuroimaging, given evidence that restricted food access may increase subsequent food intake via enhancing reward value of food and diminishing eating-related self-control. Methods:Participants were 18 preadolescents (aged 9-12 years) who were overweight/obese with recent LOC eating (OW-LOC; n = 6); overweight/obese with no history of LOC eating (OW-CON; n = 5); or non-overweight with no history of LOC eating (NW-CON; n = 7). Participants underwent functional magnetic resonance imaging during a simulated food restriction paradigm in which they were alternately given restricted or unrestricted access to milkshake solutions. Results:There were no significant main effects of restricted versus unrestricted access to milkshake flavors. Group main effects revealed increased activation for OW-LOC relative to OW-CON in areas related to attentional processes (right middle frontal gyrus), inhibitory control/attentional shifts (right and left cuneus), and emotion regulation (left cingulate gyrus); and for OW-LOC relative to NW-CON in areas related to response inhibition (right inferior frontal gyrus). Significant block type × group interaction effects were found for the right middle frontal gyrus, left cingulate gyrus, and left cuneus, but these appeared to be accounted for primarily by group. Discussion:There were clear group differences in neural activity in brain regions related to self-regulation during a food restriction paradigm. Elevations in these regions among OW-LOC relative to OW-CON and NW-CON, respectively, may suggest that youth with LOC eating expended more cognitive effort to regulate ingestive behavior.

Abstract Background Electrical muscle stimulation (EMS) induces involuntary muscle contraction. Several studies have suggested that EMS has the potential to be an alternative method of voluntary exercise; however, its effects on cerebral blood flow (CBF) when applied to large lower limb muscles are poorly understood. Thus, the purpose of this study was to examine the effects of EMS on CBF, focusing on whether the effects differ between the internal carotid (ICA) and vertebral (VA) arteries. Methods The participants performed the experiments under EMS and control (rest) conditions in a randomized crossover design. The ICA and VA blood flow were measured before and during EMS or control. Heart rate, blood pressure, minute ventilation, oxygen uptake, and end-tidal partial pressure of carbon dioxide (PETCO2) were monitored and measured as well. Results The ICA blood flow increased during EMS [Pre: 330 ± 69 mL min−1; EMS: 371 ± 81 mL min−1, P = 0.001, effect size (Cohen’s d) = 0.55]. In contrast, the VA blood flow did not change during EMS (Pre: 125 ± 47 mL min−1; EMS: 130 ± 45 mL min−1, P = 0.26, effect size = 0.12). In the EMS condition, there was a significant positive linear correlation between ΔPETCO2 and ΔICA blood flow (R = 0.74, P = 0.02). No relationships were observed between ΔPETCO2 and ΔVA blood flow (linear: R = − 0.17, P = 0.66; quadratic: R = 0.43, P = 0.55). Conclusions The present results indicate that EMS increased ICA blood flow but not VA blood flow, suggesting that the effects of EMS on cerebral perfusion differ between anterior and posterior cerebral circulation, primarily due to the differences in cerebrovascular response to CO2.

Assigning behavioral functions to neural structures has long been a central goal in neuroscience and is a necessary first step toward a circuit-level understanding of how the brain generates behavior. Here, we map the neural substrates of locomotion and social behaviors for Drosophila melanogaster using automated machine-vision and machine-learning techniques. From videos of 400,000 flies, we quantified the behavioral effects of activating 2,204 genetically targeted populations of neurons. We combined a novel quantification of anatomy with our behavioral analysis to create brain-behavior correlation maps, which are shared as browsable web pages and interactive software. Based on these maps, we generated hypotheses of regions of the brain causally related to sensory processing, locomotor control, courtship, aggression, and sleep. Our maps directly specify genetic tools to target these regions, which we used to identify a small population of neurons with a role in the control of walking.

Peripheral vasoconstriction is a centrally mediated physiological effect known to play an important role in regulating body temperature by adjusting heat exchange with the external environment. However, peripheral vasoconstriction as a component of sympathetic activation also occurs following exposure to various salient stimuli and during motivated behavior at stable environmental temperatures. This review aims to consider available evidence suggesting a significant contribution of this peripheral effect to physiological increases in both brain temperature and entry of oxygen and glucose into the brain’s extracellular space. While these effects are triggered by neuronal activation, constriction of blood vessels in the skin and most internal organs results in redistribution of blood from the peripheral to central domains, thus dilating cerebral vessels, increasing global cerebral blood flow, and enhancing the intra-brain entry of oxygen and glucose from arterial blood. This powerful influence appears to determine the long duration of physiological increases in both brain temperature and brain levels of glucose and oxygen and their basic similarity across different brain structures. This work underscores the tight interrelationship between the brain and periphery and a significant contribution of cardiovascular effects in providing the enhanced inflow of oxygen and glucose into brain tissue to prevent metabolic deficit during functional neural activation.

How an organism responds to risk depends on how that individual perceives such risk. Integrating cues from multiple sensory modalities allows individuals to extract information from their environment, and whether and how the brain and body respond differently to different sensory cues can help reveal mechanistic decision-making processes. Here, we assessed neural, hormonal, and behavioral responses to different sensory cues of predation risk in Trinidadian guppies (Poecilia reticulata). Adult guppies were assigned to one of four treatment groups: control, visual, olfactory, and both sensory cues combined from a natural predator, the pike cichlid (Crenicichla alta), for 2 h. We found no difference in glucocorticoid response to any cue. However, we found behavioral and neural activation responses to olfactory-only cues. In addition, we found a sex by treatment effect, where males showed greater changes in neural activation in brain regions associated with avoidance behavior, while females showed greater changes in neural activation in regions associated with social behavior and memory, mirroring sex by treatment differences in behavioral antipredator responses. Altogether, our results demonstrate that single and combinatory cues may influence risk-taking behavior differently based on sex, suggesting that perception and integration of cues can cascade into sex differences in behavior. • How an organism responds to predation risk depends on how it perceives risk. • Males and females often respond differently to risk. • Neural and behavioral responses to sensory cues differed between sexes in guppies. • Glucocorticoids did not change in response to any predatory cue. • Sex differences in risk perception may contribute to sex differences in behavior. [ABSTRACT FROM AUTHOR]

Cross-cultural studies suggest that people typically prefer to eat familiar foods from their own culture rather than foreign foods from other cultures. On this basis, it is plausible that neural responsiveness elicited by palatable food images from one’s own culture differ from those elicited by food depictions from other cultures. Toward clarifying this issue, we examined neural activation and self-report responses to indigenous (Chinese) versus Western food images among young Chinese adults. Participants (33 women, 33 men) viewed Chinese food, Western food and furniture control images during a functional magnetic resonance imaging (fMRI) scan and then rated the images on “liking,” “wanting,” and “difficult resisting.” Analyses indicated there were no significant differences in self-report ratings of Chinese versus Western food images. However, Chinese food images elicited stronger activation in regions linked to cravings, taste perception, attention, reward, and visual processing (i.e., cerebellum crus, superior temporal gyrus, supramarginal gyrus, middle temporal gyrus, inferior parietal lobule, posterior insula, middle occipital gyrus; inferior occipital gyrus). Conversely, Western food images elicited stronger activation in areas involved in visual object recognition and visual processing (inferior temporal gyrus, middle occipital gyrus, calcarine). These findings underscored culture as a potentially important influence on neural responses to visual food cues and raised concerns about the ecological validity of using “standard” Western food images in neuroimaging studies of non-Western samples. Results also provide foundations for designing culturally informed research and intervention approaches in non-Westerns contexts guided by the use of external food cues that are most salient to the cultural group under study.

It is difficult for stroke patients with flaccid paralysis to receive passive rehabilitation training. Therefore, virtual rehabilitation technology that integrates the motor imagery brain-computer interface and virtual reality technology has been applied to the field of stroke rehabilitation and has evolved into a physical rehabilitation training method. This virtual rehabilitation technology can enhance the initiative and adaptability of patient rehabilitation. To maximize the deep activation of the subjects motor nerves and accelerate the remodeling mechanism of motor nerve function, this study designed a brain-computer interface rehabilitation training strategy using different virtual scenes, including static scenes, dynamic scenes, and VR scenes. Including static scenes, dynamic scenes, and VR scenes. We compared and analyzed the degree of neural activation and the recognition rate of motor imagery in stroke patients after motor imagery training using stimulation of different virtual scenes, The results show that under the three scenarios, The order of degree of neural activation and the recognition rate of motor imagery from high to low is: VR scenes, dynamic scenes, static scenes. This paper provided the research basis for a virtual rehabilitation strategy that could integrate the motor imagery brain-computer interface and virtual reality technology.

Context: Although knee pain is common, some facets of this pain are unclear. The independent effects (ie, independent from other knee injury or pathology) of knee pain on neural activation of lower-extremity muscles during landing and jumping have not been observed. Objective: To investigate the independent effects of knee pain on lower-extremity muscle (gastrocnemius, vastus medialis, medial hamstrings, gluteus medius, and gluteus maximus) activation amplitude during landing and jumping, performed at 2 different intensities. Design: Laboratory-based, pretest, posttest, repeated-measures design, where all subjects performed both data-collection sessions. Methods: Thirteen able-bodied subjects performed 2 different land and jump tasks (forward and lateral) under 2 different conditions (control and pain), at 2 different intensities (high and low). For the pain condition, experimental knee pain was induced via a hypertonic saline injection into the right infrapatellar fat pad. Functional linear models were used to evaluate the influence of experimental knee pain on muscle-activation amplitude throughout the 2 land and jump tasks. Results: Experimental knee pain independently altered activation for all of the observed muscles during various parts of the 2 different land and jump tasks. These activation alterations were not consistently influenced by task intensity. Conclusion: Experimental knee pain alters activation amplitude of various lower-extremity muscles during landing and jumping. The nature of the alteration varies between muscles, intensities, and phases of the movement (ie, landing and jumping). Generally, experimental knee pain inhibits the gastrocnemius, medial hamstring, and gluteus medius during landing while independently increasing activation of the same muscles during jumping. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is insufficient knowledge about the rate of force development (RFD) characteristics over both single and multiple joint movements and the electromechanical delay (EMD) values obtained in athletes and untrained individuals. OBJECTIVE: To compare single and multiple joint functions and the neural drive of trained athletes and untrained individuals. METHODS: Eight trained athletes and 10 untrained individuals voluntarily participated to the study. The neuromuscular performance was assessed during explosive and maximum voluntary isometric contractions during leg press and knee extension related to single and multiple joint. Explosive force and surface electromyography of eight superficial lower limb muscles were measured in five 50-ms time windows from their onset, and normalized to peak force and electromyography activity at maximum voluntary force, respectively. The EMD was determined from explosive voluntary contractions (EVC's). RESULTS: The results showed that there were significant differences in absolute forces during knee extension maximum voluntary force and EVC's (p < 0.01) while trained athletes achieved greater relative forces than untrained individuals of EVC at all five time points (p < 0.05). CONCLUSIONS: The differences in explosive performance between trained athletes and untrained individuals in both movements may be explained by different levels of muscle activation within groups, attributed to variation in biarticular muscle function over both activities. [ABSTRACT FROM AUTHOR]

Background: Electrical muscle stimulation (EMS) induces involuntary muscle contraction. Several studies have suggested that EMS has the potential to be an alternative method of voluntary exercise; however, its effects on cerebral blood flow (CBF) when applied to large lower limb muscles are poorly understood. Thus, the purpose of this study was to examine the effects of EMS on CBF, focusing on whether the effects differ between the internal carotid (ICA) and vertebral (VA) arteries.Methods: The participants performed the experiments under EMS and control (rest) conditions in a randomized crossover design. The ICA and VA blood flow were measured before and during EMS or control. Heart rate, blood pressure, minute ventilation, oxygen uptake, and end-tidal partial pressure of carbon dioxide (PETCO2) were monitored and measured as well.Results: The ICA blood flow increased during EMS [Pre: 330 ± 69 mL min-1; EMS: 371 ± 81 mL min-1, P = 0.001, effect size (Cohen's d) = 0.55]. In contrast, the VA blood flow did not change during EMS (Pre: 125 ± 47 mL min-1; EMS: 130 ± 45 mL min-1, P = 0.26, effect size = 0.12). In the EMS condition, there was a significant positive linear correlation between ΔPETCO2 and ΔICA blood flow (R = 0.74, P = 0.02). No relationships were observed between ΔPETCO2 and ΔVA blood flow (linear: R = - 0.17, P = 0.66; quadratic: R = 0.43, P = 0.55).Conclusions: The present results indicate that EMS increased ICA blood flow but not VA blood flow, suggesting that the effects of EMS on cerebral perfusion differ between anterior and posterior cerebral circulation, primarily due to the differences in cerebrovascular response to CO2. [ABSTRACT FROM AUTHOR]

Peripheral vasoconstriction is a centrally mediated physiological effect known to play an important role in regulating body temperature by adjusting heat exchange with the external environment. However, peripheral vasoconstriction as a component of sympathetic activation also occurs following exposure to various salient stimuli and during motivated behavior at stable environmental temperatures. This review aims to consider available evidence suggesting a significant contribution of this peripheral effect to physiological increases in both brain temperature and entry of oxygen and glucose into the brain's extracellular space. While these effects are triggered by neuronal activation, constriction of blood vessels in the skin and most internal organs results in redistribution of blood from the peripheral to central domains, thus dilating cerebral vessels, increasing global cerebral blood flow, and enhancing the intra-brain entry of oxygen and glucose from arterial blood. This powerful influence appears to determine the long duration of physiological increases in both brain temperature and brain levels of glucose and oxygen and their basic similarity across different brain structures. This work underscores the tight interrelationship between the brain and periphery and a significant contribution of cardiovascular effects in providing the enhanced inflow of oxygen and glucose into brain tissue to prevent metabolic deficit during functional neural activation. [ABSTRACT FROM AUTHOR]

Ocean sensor data prediction has become a promising means for smart ocean monitoring. In alternative solutions, deep neural networks (DNNs) are considered as a good choice. The determination of activation functions in DNNs has a significant effect on training speed and nonlinear approximation. In this paper, the effect of activation functions on a deep computing model called deep belief echo-state network (DBEN) is studied in the scenario of ocean time series prediction. Here, different forms, including hyperbolic tangent, rectified linear unit, exponential linear unit, swish, softplus and their variants, are considered. The purpose is to investigate, from the perspectives of accuracy and training efficiency, whether certain activation function in DBEN is completely universal for the different tasks of ocean sensor data processing or not. On a great deal of real-world ocean time series of different characteristics, the results show that the selection of activation functions in DBEN is task-related. Specially, these newly introduced activation functions are more beneficial to the accurate predictions for conventional and chemical data sets compared with sigmoid benchmark. The statistical analysis further verifies this finding. [ABSTRACT FROM AUTHOR]

The globus pallidus internus and the subthalamic nucleus are common targets for deep brain stimulation to alleviate symptoms of Parkinson's disease and dystonia. In the rodent models, however, their direct targeting is hindered by the relatively large dimensions of applied electrodes. To reduce the neurological damage, the electrodes are usually implanted cranial to the nuclei, thus exposing the non-targeted brain regions to large electric fields and, in turn, possible undesired stimulation effects. In this numerical study, we analyze the spread of the fields for the conventional electrodes and several modifications. As a result, we present a relatively simple electrode design that allows an efficient focalization of the stimulating field in the inferiorly located nuclei.

In people with mental health issues, approximately 20% have co-occurring substance use, often involving cannabis. Although emotion regulation can be affected both by major depressive disorder (MDD) and by cannabis use, the relationship among all three factors is unknown. In this study, we used fMRI to evaluate the effect that cannabis use and MDD have on brain activation during an emotion regulation task. Differences were assessed in 74 emerging adults aged 16–23 with and without MDD who either used or did not use cannabis. Severity of depressive symptoms, emotion regulation style, and age of cannabis use onset were also measured. Both MDD and cannabis use interacted with the emotion regulation task in the left temporal lobe, however the location of the interaction differed for each factor. Specifically, MDD showed an interaction with emotion regulation in the middle temporal gyrus, whereas cannabis use showed an interaction in the superior temporal gyrus. Emotion regulation style predicted activity in the right superior frontal gyrus, however, this did not interact with MDD or cannabis use. Severity of depressive symptoms interacted with the emotion regulation task in the left middle temporal gyrus. The results highlight the influence of cannabis use and MDD on emotion regulation processing, suggesting that both may have a broader impact on the brain than previously thought.

Abstract Background Obesity and major depressive disorder (MDD) independently contribute to memory impairment. Little is known about shared neural mechanisms that may result in the cognitive impairment experienced by these populations. This study's aim was to determine how obesity impacts neural activity during a verbal recognition memory task in individuals both with and without MDD. Methods Functional magnetic resonance imaging was employed to examine whether differences in neural activation patterns would be seen across three groups during the Warrington's Recognition Memory Test. Three study groups are reported: 20 subjects with obesity but without MDD (bariatric controls), 23 subjects with past or current MDD and obesity, and 20 normal BMI controls (healthy controls). Results Three‐group conjunction analyses indicated that overlapping neural regions were activated during both encoding and retrieval processes across all groups. However, second‐level 2‐group t‐contrasts indicated that neural activation patterns differed when comparing healthy and bariatric controls, and when comparing bariatric controls and bariatric MDD participants. Discussion Results indicate that obesity in conjunction with MDD confers a subtle impact on neural functioning. Given high rates of obesity and MDD comorbidity, and the role of cognition on ability to return to premorbid level of functioning, this association should inform treatment decisions.

Nutrient delivery to the brain presents a unique challenge because the tissue functions as a computer system with in the order of 200,000 neurons/mm3. Penetrating arterioles bud from surface arteries of the brain and penetrate downward through the cortex. Capillary networks spread from penetrating arterioles through the surrounding tissue. Each penetrating arteriole forms a vascular unit, with little sharing of flow among vascular units (collateral flow). Unlike cells in other tissues, neurons have to be operationally isolated, interacting with other neurons through specific electrical connections. Neuronal activation typically involves only a few of the cells within a vascular unit, but the local increase in nutrient consumption is substantial. The metabolic response to activation is transmitted to the feeding arteriole through the endothelium of neighboring capillaries and alters calcium permeability of smooth muscle in the wall resulting in modulation of flow through the entire vascular unit. Many age and trauma related brain pathologies can be traced to vascular malfunction. This includes: 1. Physical damage such as in traumatic injury with imposed shear stress as soft tissue moves relative to the skull. Lack of collateral flow among vascular units results in death of the cells in that vascular unit and loss of brain tissue. 2. Age dependent changes lead to progressive increase in vascular resistance and decrease in tissue levels of oxygen and glucose. Chronic hypoxia/hypoglycemia compromises tissue energy metabolism and related regulatory processes. This alters stem cell proliferation and differentiation, undermines vascular integrity, and suppresses critical repair mechanisms such as oligodendrocyte generation and maturation. Reduced structural integrity results in local regions of acute hypoxia and microbleeds, while failure of oligodendrocytes to fully mature leads to poor axonal myelination and defective neuronal function. Understanding and treating age related pathologies, particularly in brain, requires better knowledge of why and how vasculature changes with age. That knowledge will, hopefully, make possible drugs/methods for protecting vascular function, substantially alleviating the negative health and cognitive deficits associated with growing old.

Electrical stimulation has been used for decades in devices such as pacemakers, cochlear implants and more recently for deep brain and retinal stimulation and electroceutical treatment of disease. However, current spread from the electrodes limits the precision of neural activation, leading to a low quality therapeutic outcome or undesired side-effects. Alternative methods of neural stimulation such as optical stimulation offer the potential to deliver higher spatial resolution of neural activation. Direct optical stimulation is possible with infrared light, while visible light can be used to activate neurons if the neural tissue is genetically modified with a light sensitive ion channel. Experimentally, both methods have resulted in highly precise stimulation with little spread of activation at least in the cochlea, each with advantages and disadvantages. Infrared neural stimulation does not require modification of the neural tissue, but has very high power requirements. Optogenetics can achieve precision of activation with lower power, but only in conjunction with targeted insertion of a light sensitive ion channel into the nervous system via gene therapy. This review will examine the advantages and limitations of optical stimulation of neural tissue, using the cochlea as an exemplary model and recent developments for retinal and deep brain stimulation.

The globus pallidus internus and the subthalamic nucleus are common targets for deep brain stimulation to alleviate symptoms of Parkinson's disease and dystonia. In the rodent models, however, their direct targeting is hindered by the relatively large dimensions of applied electrodes. To reduce the neurological damage, the electrodes are usually implanted cranial to the nuclei, thus exposing the non-targeted brain regions to large electric fields and, in turn, possible undesired stimulation effects. In this numerical study, we analyze the spread of the fields for the conventional electrodes and several modifications. As a result, we present a relatively simple electrode design that allows an efficient focalization of the stimulating field in the inferiorly located nuclei. [ABSTRACT FROM AUTHOR]

• Iv cocaine induces rapid neural effects revealed by high-resolution physiological techniques in freely moving animals. • The rapidity of these neural effects cannot be explained by cocaine's action on brain receptive substrates. • Rapid effects of cocaine are mimicked by peripherally acting cocaine-methiodide and resistant to dopamine receptor blockade. • The initial sites of cocaine action are receptive sites on afferents of visceral sensory nerves innervating blood vessels. • This action creates neural signal to CNS, resulting in neural activation and rapid changes in physiological parameters. Direct interaction of cocaine with centrally located monoamine transporters is the primary mechanism underlying its reinforcing properties. It is also often assumed that this drug action is responsible for all the physiological and behavioral effects of this drug. The goal of this review is to challenge this basic mechanism and demonstrate the importance of peripheral actions of cocaine in inducing its initial, rapid neural effects. The use of high-resolution electrophysiological, neurochemical and physiological techniques revealed that the effects of intravenous cocaine at behaviorally relevant doses are exceptionally rapid and transient correlating with strong, quick, and transient increases in blood cocaine levels. Some of these effects are mimicked by cocaine-methiodide, a cocaine analog that cannot cross the blood–brain barrier and they are resistant to dopamine (DA) receptor blockade. Therefore, it appears that rapid neural effects of cocaine result from its direct interaction with receptive sites on afferents of sensory nerves densely innervating blood vessels. This interaction creates a rapid neural signal to the CNS that results in generalized neural activation and subsequent changes in different physiological parameters. This drug's action appears to be independent from cocaine's action on central neurons, which requires a definite time to occur and induce neural and physiological effects with longer latencies and durations. The co-existence in the same drug on two timely distinct actions with their subsequent interaction in the CNS could explain consistent changes in physiological and behavioral effects of cocaine following their repeated use, playing a role in the development of drug-seeking and drug-taking behavior. [ABSTRACT FROM AUTHOR]

Nutrient delivery to the brain presents a unique challenge because the tissue functions as a computer system with in the order of 200,000 neurons/mm3. Penetrating arterioles bud from surface arteries of the brain and penetrate downward through the cortex. Capillary networks spread from penetrating arterioles through the surrounding tissue. Each penetrating arteriole forms a vascular unit, with little sharing of flow among vascular units (collateral flow). Unlike cells in other tissues, neurons have to be operationally isolated, interacting with other neurons through specific electrical connections. Neuronal activation typically involves only a few of the cells within a vascular unit, but the local increase in nutrient consumption is substantial. The metabolic response to activation is transmitted to the feeding arteriole through the endothelium of neighboring capillaries and alters calcium permeability of smooth muscle in the wall resulting in modulation of flow through the entire vascular unit. Many age and trauma related brain pathologies can be traced to vascular malfunction. This includes: 1. Physical damage such as in traumatic injury with imposed shear stress as soft tissue moves relative to the skull. Lack of collateral flow among vascular units results in death of the cells in that vascular unit and loss of brain tissue. 2. Age dependent changes lead to progressive increase in vascular resistance and decrease in tissue levels of oxygen and glucose. Chronic hypoxia/hypoglycemia compromises tissue energy metabolism and related regulatory processes. This alters stem cell proliferation and differentiation, undermines vascular integrity, and suppresses critical repair mechanisms such as oligodendrocyte generation and maturation. Reduced structural integrity results in local regions of acute hypoxia and microbleeds, while failure of oligodendrocytes to fully mature leads to poor axonal myelination and defective neuronal function. Understanding and treating age related pathologies, particularly in brain, requires better knowledge of why and how vasculature changes with age. That knowledge will, hopefully, make possible drugs/methods for protecting vascular function, substantially alleviating the negative health and cognitive deficits associated with growing old. [ABSTRACT FROM AUTHOR]

Aim: Reduced physical function and increased risk of falls in older adults are accompanied by age-related reductions in torque development of leg muscles, although the mechanisms and potential sex differences are not understood. Purpose: To determine the mechanistic origins (neural vs. muscular) for the age-related reduction in torque development, we compared the peak rates of torque development (RTD) during electrically-evoked and fast voluntary contractions of the knee extensors between young and older men and women. Methods: Sets of single- and double-pulse electrical stimulations evoked contractions of the knee extensor muscles in 20 young (23.0 ± 0.8 years; 10 women) and 20 older adults (78.2 ± 1.5 years; 10 women), followed by voluntary isometric knee extension contractions with torque development as fast as possible that matched the torque during electrically-evoked contraction (10–40% maximal torque). Results: Peak RTD during fast-voluntary contractions was 41% less than electrically-evoked contractions (p < 0.001), but more so for older adults (44%) than young (38%, p = 0.04), with no sex differences. Peak RTD during fast-voluntary contractions was more variable between contractions for the older than young adults (77%MVC s−1 vs. 47%MVC s−1, p < 0.001). Additionally, older women exhibited greater variability than older men (81%MVC s−1 vs. 72%MVC s−1, p = 0.04) with no sex-related differences within the young adults. Conclusion: Older adults had slower and more variable RTD during voluntary contractions than young adults, particularly older women. The limited age-related differences in electrically-evoked RTD suggest the primary mechanism for the slower torque development of the knee extensor muscles in older men and women involve reduced neural activation. [ABSTRACT FROM AUTHOR]

To clarify the different regional brain electroencephalogram (EEG) activities and biochemical responses in seizure and epilepsy models, we assessed the EEG and c-Fos immunolabeling characteristics in a lithium-pilocarpine-induced status epilepticus (SE) model and pentylenetetrazol (PTZ)-induced seizure model. The regional brain activities were evaluated by EEG and c-Fos immunolabeling. ZnT3 immunostaining was performed to observe hippocampal mossy fiber sprouting (MFS) within 7 days after the induction of SE in the lithium-pilocarpine model. The EEG recordings showed distinctive features of activation in different brain areas. With the aggravation of the behavioral manifestations of the seizures, the frequency and amplitude of the discharges on EEG gradually increased. SE was eventually induced and sustained. The labeling of c-Fos was enhanced in the cortex and hippocampal CA1, CA3, and dentate gyrus (DG); however, compared to the PTZ-induced seizure model, c-Fos staining could only be observed in the striatum and thalamus in the lithium-pilocarpine-induced epilepsy model. In each brain region, prominent c-Fos labeling was observed 2 h and 4 h after the induction of SE or seizures and diminished at 24 h. During the lithium-pilocarpine-induced chronic epilepsy phase after SE induction, MFS was observed 7 days after SE and was accompanied by the dynamic evolution of epileptic EEG activities. These findings validated the lithium-pilocarpine-induced SE model as an epilepsy model with a specific spatial-temporal profile of neural activation. The EEG characteristics and c-Fos expression patterns differ from those presented in a previous study using a PTZ-induced seizure model. Hippocampal mossy fiber spouting might be associated with spontaneous seizures during the chronic phase and can be detected at least within 1 week by ZnT3 staining after stimulation.

Preoperative baseline cognitive impairment is associated with postoperative neurocognitive disorder (PND). Fasting, and more generally, calorie restriction has been shown to exert controversial effects in clinical settings and various animal models of neurological disorders. Every patient needs acute fasting before anesthesia and surgery. However, the impact of acute fasting on cognitive function remain largely unknown. We, therefore, set out to determine whether acute fasting can induce neurotoxicity and neurobehavioral deficits in rodents. In the present system establishment study, a mouse model of acute fasting was established. The effects of the acute fasting on natural and learned behavior were evaluated in the buried food test, open field test and the Y maze test. The expression of c-Fos, the marker of neuronal activation, and caspase-3 activation, the marker of cellular apoptosis, were measured with immunohistochemistry. We found that the 9 h acute fasting increased the latency to eat food in the buried food test. The acute fasting also selectively increased the total distance and decreased the freezing time in open field test, and increased the duration in the novel arm in the Y maze test. Besides, the immunohistochemical study showed that the fasting significantly increased the c-Fos level in the hippocampus and various sub-cortical areas, including paraventricular thalamus (PVT), dorsomedial hypothalamus (DMH), lateral hypothalamus (LH), and basal amygdala (BMA). However, the acute fasting did not induce apoptosis, demonstrating by no appearance of caspase-3 activation in the corresponding brain areas. These data showed that acute fasting did not cause cellular apoptosis and cognitive impairment in the mice. Instead, the acute fasting increased the neuronal activity, enhanced the ambulatory activity and improved the spatial recognition memory in the mice. These findings will promote more research in the established system to further determine the effects of perioperative factors on the postoperative neurocognitive function and the underlying mechanisms.

Background. Interpersonal distance (IPD) plays a critical role in a human being’s social life, especially during interpersonal interaction, and IPD is non-verbal social information and not only provides silent cues but also provides a secure space for personal relationships. IPD has been a research field of neural studies from the recent decade, researches had provided behavior and neural correlates of IPD. Objectives. This review aims to summarize the experimental paradigms of IPD-neural research, to reveal the neural activity processes associated with it, and to explore the correlation between IPD-neural activity and IPD-behavior. Methods. We conducted a standardized systematic review procedure, including the formal search method be adopted to seek out any type of studies related to IPD and brain, then devised them into categories to make a systematic review. Results. 17 articles met the inclusion criteria of the review, 5 event-related potential (ERP) studies measured the amplitude and latencies of ERPs, and 12 functional magnetic resonance imaging (fMRI) studies provided the neural activation during IPD tasks. In addition, the passive IPD experimental paradigm is the main experimental paradigm for exploring neural activity in IPD cognition, with the parietal lobe, motor areas, prefrontal lobe, and amygdala being the main brain areas involved. Functional connections between the identified brain regions were found and have a moderate correlation with IPD behavior. Conclusions. This review provides the neural activity of the IPD interaction process. However, the insufficient ecological validity of IPD tasks and ignore the initiative of people in IPD interaction. Therefore, there is a large research space on this topic. The work of the current systematic review contributed to linking the external performance and inner neural activities of IPD.

New Findings: What is the central question of this study?The effects of long‐term muscle disuse on neuromuscular function are unclear because disuse studies are typically short term. In this study, we used a new model (unilateral transtibial amputees) to investigate the effects of long‐term disuse on quadriceps neuromuscular function.What is the main finding and its importance?Kinetic analysis (knee‐extension moments during gait) indicated habitual disuse of the amputated limb quadriceps, accompanied by lower quadriceps muscle strength (60–76%) and neural activation (32–44%), slower contractile properties and altered muscle architecture in the amputated limb, which could not be predicted from short‐term disuse studies. The purpose of this study was to determine: (i) whether individuals with unilateral transtibial amputations (ITTAs), who habitually disuse the quadriceps muscles of their amputated limb, provide an effective model for assessing the effects of long‐term muscle disuse; and (ii) the effects of such disuse on quadriceps muscle strength and neuromuscular function in this population. Nine ITTAs and nine control subjects performed isometric voluntary knee extensions of both limbs to assess maximal voluntary torque (MVT) and the rate of torque development (RTD). The interpolated twitch technique and EMG normalized to maximal M‐wave were used to assess neural activation, involuntary (twitch and octet) contractions to assess intrinsic contractile properties, and ultrasound images of the vastus lateralis to assess muscle architecture. Clinical gait analysis was used to measure knee kinetic data during walking at an habitual speed. The ITTAs displayed 54–60% lower peak knee‐extensor moments during walking in the amputated compared with intact/control limbs, but the intact and control limbs were comparable for loading during walking and muscle strength variables, suggesting that the intact limb provides a suitable internal control for comparison with the disused amputated limb. The MVT and RTD were ∼60 and ∼75% lower, respectively, in the amputated than intact/control limbs. The differences in MVT appeared to be associated with ∼40 and ∼43% lower muscle thickness and neural activation, respectively, and the differences in RTD appeared to be associated with the decline in MVT coupled with slowing of the intrinsic contractile properties. These results indicate considerable changes in strength and neuromuscular function with long‐term disuse that could not be predicted from short‐term disuse studies. [ABSTRACT FROM AUTHOR]

• People with obesity shows greater response to food cues in visual-attention related areas. • High calories food induced greater activation in reward areas in people with obesity. • Healthy weight group shows greater response to food cues in gustatory area. • Greater inhibitory control for food cues is elicited in healthy weight group. Growing researches have shown that obese/overweight and healthy weight individuals exhibit different neural responses to food-related stimuli. Accordingly, researchers proposed several theories to explain these differences. Hereon, meta-analyses were conducted using activation likelihood estimation (ALE) to verify these theories and specify the reason of overeating from two aspects. Pubmed, Web of Science and Neurosynth were searched for the current study and screened according to inclusion criteria. Firstly, neural responses to visual food cues versus non-food images were compared between obese/overweight and healthy weight individuals. Then, neural activation to high-calorie food images versus low-calorie food/non-food visual stimuli was further investigated among the two populations. Coordinates in included studies were recorded and analysed by Ginger ALE software under threshold at uncorrected p < 0.001 with cluster-level p < 0.05 (cFWE). Eleven and seven studies were found in the first and second set of meta-analysis, respectively. The first meta-analysis showed that obese/overweight have hyper-responsivity in reward area and hypo-responsivity in both gustatory processing and inhibitory control area. The second meta-analysis indicated that the reward responsivity in the obese/overweight individuals was amplified and healthy weight individuals had higher activation in areas associated with gustatory processing in response to high-calorie food images. Our results showed that the obese/overweight exhibit hyper-responsivity in brain regions involved in reward processing for visual food cue which provide strong support for incentive-sensitization theory of obesity and healthy weight individuals showed higher response in inhibitory control region which support the inhibitory control deficit theory of obesity. [ABSTRACT FROM AUTHOR]

To clarify the different regional brain electroencephalogram (EEG) activities and biochemical responses in seizure and epilepsy models, we assessed the EEG and c-Fos immunolabeling characteristics in a lithium-pilocarpine-induced status epilepticus (SE) model and pentylenetetrazol (PTZ)-induced seizure model. The regional brain activities were evaluated by EEG and c-Fos immunolabeling. ZnT3 immunostaining was performed to observe hippocampal mossy fiber sprouting (MFS) within 7 days after the induction of SE in the lithium-pilocarpine model. The EEG recordings showed distinctive features of activation in different brain areas. With the aggravation of the behavioral manifestations of the seizures, the frequency and amplitude of the discharges on EEG gradually increased. SE was eventually induced and sustained. The labeling of c-Fos was enhanced in the cortex and hippocampal CA1, CA3, and dentate gyrus (DG); however, compared to the PTZ-induced seizure model, c-Fos staining could only be observed in the striatum and thalamus in the lithium-pilocarpine-induced epilepsy model. In each brain region, prominent c-Fos labeling was observed 2 h and 4 h after the induction of SE or seizures and diminished at 24 h. During the lithium-pilocarpine-induced chronic epilepsy phase after SE induction, MFS was observed 7 days after SE and was accompanied by the dynamic evolution of epileptic EEG activities. These findings validated the lithium-pilocarpine-induced SE model as an epilepsy model with a specific spatial-temporal profile of neural activation. The EEG characteristics and c-Fos expression patterns differ from those presented in a previous study using a PTZ-induced seizure model. Hippocampal mossy fiber spouting might be associated with spontaneous seizures during the chronic phase and can be detected at least within 1 week by ZnT3 staining after stimulation. [ABSTRACT FROM AUTHOR]

The ability to recognize others' emotions based on vocal emotional prosody follows a protracted developmental trajectory during adolescence. However, little is known about the neural mechanisms supporting this maturation. The current study investigated age-related differences in neural activation during a vocal emotion recognition (ER) task. Listeners aged 8 to 19 years old completed the vocal ER task while undergoing functional magnetic resonance imaging. The task of categorizing vocal emotional prosody elicited activation primarily in temporal and frontal areas. Age was associated with a) greater activation in regions in the superior, middle, and inferior frontal gyri, b) greater functional connectivity between the left precentral and inferior frontal gyri and regions in the bilateral insula and temporo-parietal junction, and c) greater fractional anisotropy in the superior longitudinal fasciculus, which connects frontal areas to posterior temporo-parietal regions. Many of these age-related differences in brain activation and connectivity were associated with better performance on the ER task. Increased activation in, and connectivity between, areas typically involved in language processing and social cognition may facilitate the development of vocal ER skills in adolescence. [ABSTRACT FROM AUTHOR]

It is well known that temperature affects the dynamics of all physicochemical processes governing neural activity. It is also known that the brain has high levels of metabolic activity, and all energy used for brain metabolism is finally transformed into heat. However, the issue of brain temperature as a factor reflecting neural activity and affecting various neural functions remains in the shadow and is usually ignored by most physiologists and neuroscientists. Data presented in this review demonstrate that brain temperature is not stable, showing relatively large fluctuations (2-4°C) within the normal physiological and behavioral continuum. I consider the mechanisms underlying these fluctuations and discuss brain thermorecording as an important tool to assess basic changes in neural activity associated with different natural (sexual, drinking, eating) and drug-induced motivated behaviors. I also consider how naturally occurring changes in brain temperature affect neural activity, various homeostatic parameters, and the structural integrity of brain cells as well as the results of neurochemical evaluations conducted in awake animals. While physiological hyperthermia appears to be adaptive, enhancing the efficiency of neural functions, under specific environmental conditions and following exposure to certain psychoactive drugs, brain temperature could exceed its upper limits, resulting in multiple brain abnormalities and life-threatening health complications. [ABSTRACT FROM AUTHOR]

Preoperative baseline cognitive impairment is associated with postoperative neurocognitive disorder (PND). Fasting, and more generally, calorie restriction has been shown to exert controversial effects in clinical settings and various animal models of neurological disorders. Every patient needs acute fasting before anesthesia and surgery. However, the impact of acute fasting on cognitive function remain largely unknown. We, therefore, set out to determine whether acute fasting can induce neurotoxicity and neurobehavioral deficits in rodents. In the present system establishment study, a mouse model of acute fasting was established. The effects of the acute fasting on natural and learned behavior were evaluated in the buried food test, open field test and the Y maze test. The expression of c-Fos, the marker of neuronal activation, and caspase-3 activation, the marker of cellular apoptosis, were measured with immunohistochemistry. We found that the 9 h acute fasting increased the latency to eat food in the buried food test. The acute fasting also selectively increased the total distance and decreased the freezing time in open field test, and increased the duration in the novel arm in the Y maze test. Besides, the immunohistochemical study showed that the fasting significantly increased the c-Fos level in the hippocampus and various sub-cortical areas, including paraventricular thalamus (PVT), dorsomedial hypothalamus (DMH), lateral hypothalamus (LH), and basal amygdala (BMA). However, the acute fasting did not induce apoptosis, demonstrating by no appearance of caspase-3 activation in the corresponding brain areas. These data showed that acute fasting did not cause cellular apoptosis and cognitive impairment in the mice. Instead, the acute fasting increased the neuronal activity, enhanced the ambulatory activity and improved the spatial recognition memory in the mice. These findings will promote more research in the established system to further determine the effects of perioperative factors on the postoperative neurocognitive function and the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Purpose: To confirm different local brain activities characterized in pentylenetetrazol (PTZ)-induced seizure model. Methods: we induced seizure response by a single dose of PTZ injection (45 mg/kg, i.p.). Local activity was recorded in different brain regions by EEG in time and c-Fos staining at different time points (0.5 h, 1 h, 2 h, 4 h) after PTZ treatment. Results: EEG recordings showed distinctive features of activation in different brain areas. With the aggravation of behavioral manifestations of seizures, the frequency and amplitude of the discharges on EEG were increasing gradually. The epileptic response on EEG immediately ended after reaching the maximum stage of seizures, followed by a short period of suppression. The labeling of c-Fos was enhanced in the medial prefrontal cortex, the piriform cortex, the amygdala, hippocampal CA1, CA3 and dentate gyrus, but inapparent in the striatum. The most potent changes in c-Fos were observed in cortex, amygdala nuclei, and dentate gyrus. EEG and c-Fos immunolabeling in neuronal activation showed discrepancies in the striatum. For each brain region, the maximum c-Fos labeling was observed at 2 h after injection and diminished at 4 h. The level of c-Fos immunoreactivity was even lower than the control group, which was accompanied by increased labeling of parvalbumin neurons (PVNs). Conclusions: These findings validated PTZ-induced seizure as a seizure model with a specific spatial-temporal profile. Neuronal activity was enhanced and then subsequently inhibited during seizure evolution. Abbreviations: AEDs: anti-epileptic drugs; AF: Alexa Fluor; CA1: Cornu Ammonis area 1; CA3: Cornu Ammonis area 3; DAB, 3: 3P-diaminobenzidine; DAPI: 4',6-diamidino-2-phenylindole; DG: dentate gyrus; EEG: electroencephalogram; GABA: gamma-aminobutyric acid; IEG: immediate early gene; mPFC: medial prefrontal cortex; NAc: nucleus accumbens; PB: phosphate buffer; PBS: phosphate buffered saline; PBST: phosphate buffered saline with Tween; PFA, paraformaldehyde; PTZ: pentylenetetrazol; PVN: parvalbumin neuron; ROI: regions of interest; SE: status epilepticus. [ABSTRACT FROM AUTHOR]