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Gamma time–frequency responses (TFRs) induced by painful laser in the contralateral primary somatosensory (SI) cortex have been shown to correlate with perceived pain-intensity in human. Given the functional roles of gamma TFRs in the cortical spaces, it remains unclear whether such a relationship is sustained for other brain regions where the laser-evoked potentials (LEPs) are presented. In this study, we delivered the painful laser pluses at random pain-intensity levels (i.e. strong, medium and weak) in a single train to the dorsal hand of six patients with uncontrolled epilepsy. The laser stimulus produced a painful pinprick sensation by activating nociceptors located in the superficial layers of the skin. For each patient, arrays of >64 subdural electrodes were implanted directly covering the contralateral SI, parasylvian (PS) and medial frontal (MF) cortices to study the stimulus related gamma (TFRs) in the neocortex. In addition, using the same stimulation paradigm, the modality specificity of gamma TFRs was further examined by applying innocuous vibrotactile stimuli to the same regions of the dorsal hand in a separated group of five patients. Our results showed that gamma TFRs are not modality specific, but the largest gamma TFRs were consistently found within the SI region and noxious laser elicited significantly stronger gamma TFRs than innocuous nonpainful vibratory stimuli. Furthermore, stronger pain induced stronger gamma TFRs in the cortices of SI ( r = 0.4, p < 0.001) and PS ( r = 0.29, p = 0.005). Given that potentially harmful noxious stimulus would automatically capture greater attention than the innocuous ones, our results support the hypothesis that the degree of SI and PS gamma TFRs is associated with an attentional drive provoked by painful stimuli. [ABSTRACT FROM AUTHOR]

Highlights: [•] We examined mPFC activity during memory retrieval and extinction under anesthesia. [•] mPFC activity increased after CS+/US pairings but not after US presentations alone. [•] During retrieval, mPFC activity increased more during CS+ than CS− presentation. [•] After extinction, mPFC activity did not differ between CS+ and CS− presentation. [•] Memory retrieval and extinction are encoded by mPFC activity under anesthesia. [Copyright &y& Elsevier]

Highlights: [•] We examine the emergence of 600-Hz buzz UP state of Purkinje cell in alert mice. [•] Climbing fiber input is able to switch the 600-Hz buzz to the DOWN state. [•] 600Hz increases the CS frequency indicating inferior olive disinhibition. [•] A single PC model is able to reproduce the 600-Hz buzz. [Copyright &y& Elsevier]

Highlights: [•] We examined the effect of STN-DBS on the striatal monoamine and STN activities. [•] The levels of 3–4-dihydroxyphenylacetic acid (DOPAC) were significantly decreased after the cessation of stimulation in PD model rats. [•] STN beta power was elevated in normal rats and decreased in PD rats by STN-DBS. [•] The STN beta power and the levels of DOPAC and 5-HT were positively correlated in PD model rats. [ABSTRACT FROM AUTHOR]

Highlights: [•] We recorded visual responses of population signals in the mouse visual cortex. [•] We characterized visual responses of multiunit activity and local field potentials. [•] Visual latency of population signals is as short as ∼30ms. [•] Population signals exhibit large receptive fields ∼40°. [•] Orientation tuning is absent in population signals in mouse visual cortex. [ABSTRACT FROM AUTHOR]

Highlights: [•] CSD enhanced lipid peroxidation in cortex, meninges and trigeminal ganglia. [•] H2O2 enhanced spiking of trigeminal nerves and promoted CGRP release. [•] Effect of H2O2 on spiking was abolished by the TRPA1 antagonist. [•] Oxidative stress could couple CSD with activation of the trigeminovascular system. [ABSTRACT FROM AUTHOR]

Highlights: [•] Early gamma oscillations are transiently expressed in neonatal rat barrel cortex. [•] Feedforward gamma-rhythmic input from thalamus is essential for EGOs. [•] GABAergic inhibition plays little role in EGOs. [•] EGOs bind thalamus and cortex and support spike-time-dependent plasticity. [•] Inhibition based “adult” gamma oscillations emerge late in development. [ABSTRACT FROM AUTHOR]

Highlights: [•] Rats learn to associate two cues to reward cells and goal-associated place cells. [•] Unbiased and biased look-ahead scans activate grid cells ahead of the animal. [•] Spatial decoding of entorhinal neurons produces forward activations with look-ahead. [•] Biased look-ahead better emulates forward activation seen in vivo during correct laps. [•] Unbiased look-ahead better emulates forward activation seen in vivo during error laps. [Copyright &y& Elsevier]

Highlights: [•] Recent infant care experience can alter sensory cortical response to infant calls. [•] Infant care experience alone is insufficient for long-term salience of calls. [•] Mom’s physiological state during infant care maintains call salience and plasticity. [•] Spontaneous firing of call-encoding neurons is selectively suppressed in moms. [Copyright &y& Elsevier]

Highlights: [•] CN–SG local field potential pairs were recorded and analyzed. [•] Our results suggest bidirectional information flow between the CN and the SG. [•] Co-oscillation was found during visual stimulation between the CN and the posterior thalamus. [•] Static stimulation increased the cross-correlation of the beta frequency components. [•] Dynamic visual stimulation was reflected by changes in the theta frequency signal. [ABSTRACT FROM AUTHOR]

Abstract: Investigations of local field potentials of the subthalamic nucleus of patients with Parkinson’s disease have provided evidence for pathologically exaggerated oscillatory beta-band activity (13–30Hz) which is amenable to physiological modulation by, e.g., voluntary movement. Previous functional magnetic resonance imaging studies in healthy controls have provided evidence for an increase of subthalamic nucleus blood-oxygenation-level-dependant signal in incremental force generation tasks. However, the modulation of neuronal activity by force generation and its relationship to peripheral feedback remain to be elucidated. We hypothesised that beta-band activity in the subthalamic nucleus is modulated by incremental force generation. Subthalamic nucleus local field potentials were recorded intraoperatively in 13 patients with Parkinson’s disease (37 recording sites) during rest and five incremental isometric force generation conditions of the arm with applied loads of 0–400g (in 100-g increments). Repeated measures analysis of variance (ANOVA) revealed a modulation of local field potential (LFP) power in the upper beta-band (in 24–30Hz; F (3.042) =4.693, p =0.036) and the gamma-band (in 70–76Hz; F (4) =4.116, p =0.036). Granger-causality was computed with the squared partial directed coherence and showed no significant modulation during incremental isometric force generation. Our findings indicate that the upper beta- and gamma-band power of subthalamic nucleus local field potentials are modulated by the physiological task of force generation in patients with Parkinson’s disease. This modulation seems to be not an effect of a modulation of peripheral feedback. [Copyright &y& Elsevier]

Highlights: [•] Extensive review on mPFC functions in conditioned fear behavior. [•] Contribution of mPFC neuronal elements and circuits in fear behavior. [•] Detailed neuronal and cellular mechanisms involved in the regulation of fear memory. [•] Neuronal rate and temporal encoding of fear responses in the mPFC. [•] Optogenetic strategies to causally relate mPFC circuits and fear behavior. [ABSTRACT FROM AUTHOR]

Abstract: The basal ganglia play a critical role in controlling seizures in animal models of idiopathic non-convulsive (absence) epilepsy. Inappropriate output from the substantia nigra pars reticulata (SNr) is known to exacerbate seizures, but the precise neuronal mechanisms underlying abnormal activity in SNr remain unclear. To test the hypothesis that cortical spike-wave oscillations, often considered indicative of absence seizures, propagate to the subthalamic nucleus, an important afferent of SNr, we simultaneously recorded local field potentials from the frontal cortex and subthalamic nucleus of freely moving rats. Spontaneous spike-wave oscillations in cortex (mean dominant frequency of 7.4 Hz) were associated with similar oscillations in the subthalamic nucleus (mean of 7.9 Hz). The power of oscillations at 5–9 Hz was significantly higher during spike-wave activity as compared with rest periods without this activity. Importantly, spike-wave oscillations in cortex and subthalamic nucleus were significantly coherent across a range of frequencies (3–40 Hz), and the dominant (7–8 Hz) oscillatory activity in the subthalamic nucleus typically followed that in cortex with a small time lag (mean of 2.7 ms). In conclusion, these data suggest that ensembles of subthalamic nucleus neurons are rapidly recruited into oscillations during cortical spike-wave activity, thus adding further weight to the importance of the subthalamic nucleus in absence epilepsy. An increase in synchronous oscillatory input from the subthalamic nucleus could thus partly underlie the expression of pathological activity in SNr that could, in turn, aggravate seizures. Finally, these findings also reiterate the importance of oscillations in these circuits in normal behaviour. [Copyright &y& Elsevier]

To test the hypotheses that (i) electroencephalograms (EEGs) are largely made up of oscillations at many frequencies and (ii) that the peaks in the power spectra represent oscillations, we applied a new method, called the period specific average (PSA) to a wide sample of EEGs. Both hypotheses can be rejected.Although the principal peaks in the two spectra agree most of the time, quite often a peak in the power spectrum accompanies no periodicity peak and some periodicity peaks have no power spectral peak. The Fourier spectrum is not a reliable indication of rhythms. EEG samples from patients during waking, sleeping and seizure states, and volunteer healthy subjects doing cognitive tasks quite often show no significant rhythms, on an arbitrary, common sense definition. When clear rhythms are seen, they involve one or two, rarely up to four or five simultaneous non-harmonically related frequencies. Rhythms are special cases; most of the power spectrum most of the time is nonrhythmic. “Good” rhythms usually have quite narrow peaks, with frequency modulation of <5%, strengths of >2.5 up to >10 times the expectation from chance, and they often show fine structure by being quite local and brief. Most rhythms are quasisinusoidal but others are sharp-cornered recurrent events with <50% duty cycle. In the face of wide variability, we do not report any systematic differences in periodicity among EEGs from different parts of the brain or different brain states or species; it will take many more exemplars of each state, species or brain part to establish characteristic features.The PSA method may be the best so far proposed to demonstrate and quantify periodicity in wide-band time series with noise, but it has serious limitations. Discussion leads to the conclusion that it is time for a new paradigm or metaphor for brain waves. [Copyright &y& Elsevier]