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Antibody assay for SARS-CoV-2 has become increasingly important to track latent and asymptomatic infections, check the individual's immune status, and confirm vaccine efficacy and durability. However, current SARS-CoV-2 antibody assays require invasive blood collection, requiring a remote laboratory and a trained phlebotomist. Direct detection of SARS-CoV-2 antibodies from clinical saline gargle samples has been considered challenging due to the smaller number of antibodies in such specimens and the high limit of detection of currently available rapid tests. This work demonstrates simple and non-invasive methods for detecting SARS-CoV-2 salivary antibodies. Competitive particle immunoassays were developed on a paper microfluidic chip using the receptor-binding domain (RBD) antigens on spike proteins. Using a smartphone, they were monitored by counting the captured fluorescent particles or evaluating the capillary flow velocities. The limit of detection (LOD), cross-binding between alpha- and omicron-strains, and the effect of angiotensin-converting enzyme 2 (ACE2) presence were investigated. LODs were 1-5 ng/mL in both 10% and 1% saliva. Clinical saline gargle samples were assayed using both methods, showing a statistical difference between virus-negative and virus-positive samples, although the assays targeted antibodies. Only a small number of virus-positive samples were antibody-negative. The high assay sensitivity detected a small number of antibodies developed even during the early phase of infections. Overall, this work demonstrates the ability to detect SARS-CoV-2 salivary IgG antibodies on simple, cost-effective, portable platforms towards mitigating SARS-CoV-2 and potentially other respiratory viruses., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Respiratory viruses, especially coronaviruses, have resulted in worldwide pandemics in the past couple of decades. Saliva-based paper microfluidic assays represent an opportunity for noninvasive and rapid screening, yet both the sample matrix and test method come with unique challenges. In this work, we demonstrated the rapid and sensitive detection of SARS-CoV-2 from saliva samples, which could be simpler and more comfortable for patients than existing methods. Furthermore, we systematically investigated the components of saliva samples that affected assay performance. Using only a smartphone, an antibody-conjugated particle suspension, and a paper microfluidic chip, we made the assay user-friendly with minimal processing. Unlike the previously established flow rate assays that depended solely on the flow rate or distance, this unique assay analyzes the flow profile to determine infection status. Particle-target immunoagglutination changed the surface tension and subsequently the capillary flow velocity profile. A smartphone camera automatically measured the flow profile using a Python script, which was not affected by ambient light variations. The limit of detection (LOD) was 1 fg/μL SARS-CoV-2 from 1% saliva samples and 10 fg/μL from simulated saline gargle samples (15% saliva and 0.9% saline). This method was highly specific as demonstrated using influenza A/H1N1. The sample-to-answer assay time was <15 min, including <1-min capillary flow time. The overall accuracy was 89% with relatively clean clinical saline gargle samples. Despite some limitations with turbid clinical samples, this method presents a potential solution for rapid mass testing techniques during any infectious disease outbreak as soon as the antibodies become available., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Saliva specimens have drawn interest for diagnosing respiratory viral infections due to their ease of collection and decreased risk to healthcare providers. However, rapid and sensitive immunoassays have not yet been satisfactorily demonstrated for such specimens due to their viscosity and low viral loads. Using paper microfluidic chips and a smartphone-based fluorescence microscope, we developed a highly sensitive, low-cost immunofluorescence particulometric SARS-CoV-2 assay from clinical saline gargle samples. We demonstrated the limit of detection of 10 ag/μL. With easy-to-collect saline gargle samples, our clinical sensitivity, specificity, and accuracy were 100%, 86%, and 93%, respectively, for n  = 27 human subjects with n  = 13 RT-qPCR positives., (© The Author(s) 2022. Published by Oxford University Press on behalf of the National Academy of Sciences.)

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have shown high efficacy, but immunocompromised participants were excluded from controlled clinical trials. In this study, we compared immune responses to the BNT162b2 mRNA Coronavirus Disease 2019 vaccine in patients with solid tumors (n = 53) who were on active cytotoxic anti-cancer therapy to a control cohort of participants without cancer (n = 50). Neutralizing antibodies were detected in 67% of patients with cancer after the first immunization, followed by a threefold increase in median titers after the second dose. Similar patterns were observed for spike protein-specific serum antibodies and T cells, but the magnitude of each of these responses was diminished relative to the control cohort. In most patients with cancer, we detected spike receptor-binding domain and other S1-specific memory B cell subsets as potential predictors of anamnestic responses to additional immunizations. We therefore initiated a phase 1 trial for 20 cancer cohort participants of a third vaccine dose of BNT162b2 ( NCT04936997 ); primary outcomes were immune responses, with a secondary outcome of safety. At 1 week after a third immunization, 16 participants demonstrated a median threefold increase in neutralizing antibody responses, but no improvement was observed in T cell responses. Adverse events were mild. These results suggest that a third dose of BNT162b2 is safe, improves humoral immunity against SARS-CoV-2 and could be immunologically beneficial for patients with cancer on active chemotherapy., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

In December of 2019, a novel coronavirus, SARS-CoV-2, emerged in the city of Wuhan, China, causing severe morbidity and mortality. Since then, the virus has swept across the globe, causing millions of confirmed infections and hundreds of thousands of deaths. To better understand the nature of the pandemic and the introduction and spread of the virus in Arizona, we sequenced viral genomes from clinical samples tested at the TGen North Clinical Laboratory, the Arizona Department of Health Services, and those collected as part of community surveillance projects at Arizona State University and the University of Arizona. Phylogenetic analysis of 84 genomes from across Arizona revealed a minimum of 11 distinct introductions inferred to have occurred during February and March. We show that >80% of our sequences descend from strains that were initially circulating widely in Europe but have since dominated the outbreak in the United States. In addition, we show that the first reported case of community transmission in Arizona descended from the Washington state outbreak that was discovered in late February. Notably, none of the observed transmission clusters are epidemiologically linked to the original travel-related case in the state, suggesting successful early isolation and quarantine. Finally, we use molecular clock analyses to demonstrate a lack of identifiable, widespread cryptic transmission in Arizona prior to the middle of February 2020. IMPORTANCE As the COVID-19 pandemic swept across the United States, there was great differential impact on local and regional communities. One of the earliest and hardest hit regions was in New York, while at the same time Arizona (for example) had low incidence. That situation has changed dramatically, with Arizona now having the highest rate of disease increase in the country. Understanding the roots of the pandemic during the initial months is essential as the pandemic continues and reaches new heights. Genomic analysis and phylogenetic modeling of SARS-COV-2 in Arizona can help to reconstruct population composition and predict the earliest undetected introductions. This foundational work represents the basis for future analysis and understanding as the pandemic continues., (Copyright © 2020 Ladner et al.)

Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts and repetitive, compulsive behaviors. While a cortico-striatal-limbic network has been implicated in the pathophysiology of OCD, the neural correlates of this network in OCD are not well understood. In this study, we examined resting state functional connectivity among regions within the cortico-striatal-limbic OCD neural network, including the rostral anterior cingulate cortex, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, orbitofrontal cortex, ventromedial prefrontal cortex, amygdala, thalamus and caudate, in 44 OCD and 43 healthy participants. We then examined relationships between OCD neural network connectivity and OCD symptom severity in OCD participants. OCD relative to healthy participants showed significantly greater connectivity between the left caudate and bilateral dorsolateral prefrontal cortex. We also found a positive correlation between left caudate-bilateral dorsolateral prefrontal cortex connectivity and depression scores in OCD participants, such that greater positive connectivity was associated with more severe symptoms. This study makes a significant contribution to our understanding of functional networks and their relationship with depression in OCD., Competing Interests: Declaration of Competing Interest The authors report no biomedical financial interests or potential conflicts of interest., (Published by Elsevier B.V.)

Background: Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts and repetitive, compulsive behaviors. Neuroimaging studies have implicated altered connectivity among the functional networks of the cerebral cortex in the pathophysiology of OCD. However, there has been no comprehensive investigation of the cross-talk between the cerebellum and functional networks in the cerebral cortex., Methods: This functional neuroimaging study was completed by 44 adult participants with OCD and 43 healthy control participants. We performed large-scale data-driven brain network analysis to identify functional connectivity patterns using resting-state functional magnetic resonance imaging data., Results: Participants with OCD showed lower functional connectivity within the somatomotor network and greater functional connectivity among the somatomotor network, cerebellum, and subcortical network (e.g., thalamus and pallidum; all p < .005). Network-based statistics analyses demonstrated one component comprising connectivity within the somatomotor network that showed lower connectivity and a second component comprising connectivity among the somatomotor network, and motor regions in particular, and the cerebellum that showed greater connectivity in participants with OCD relative to healthy control participants. In participants with OCD, abnormal connectivity across both network-based statistics-derived components positively correlated with OCD symptom severity (p = .006)., Conclusions: To our knowledge, this study is the first comprehensive investigation of large-scale network alteration across the cerebral cortex, subcortical regions, and cerebellum in OCD. Our findings highlight a critical role of the cerebellum in the pathophysiology of OCD., (Published by Elsevier Inc.)

Drug addiction is associated with dysfunction in the medial prefrontal cortex (mPFC). However, the modifications of neuronal activity in mPFC underlying the reinforcing properties of addictive drugs are still unclear. Here we carried out single-unit recording experiments to study the neuronal activity in the prelimbic (PL) cortex of anesthetized rats, after expression of locomotor sensitization to amphetamine. In control rats, an acute injection of amphetamine induced mainly an inhibitory effect on firing rate (FR) and this response was negatively correlated with the basal FR. Sensitized rats showed a higher proportion of excited neurons and the response to amphetamine was independent of basal FR. Moreover, in control rats, acute amphetamine decreased burst rate, whereas in sensitized rats acute amphetamine increased burst rate. These findings indicate that amphetamine sensitization renders mPFC neurons hyperexcitable. Taken together, these data support the hypothesis that early withdrawal is associated with an increase in the activity of the mPFC, which could strengthen the PL-Nucleus Accumbens connection, thus facilitating amphetamine-induced locomotor sensitization., (Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.)

Extinction of conditioned fear to a tone paired with foot shock is thought to involve the formation of new memory. In support of this, previous studies have shown that extinction of conditioned fear depends on NMDA receptor-mediated plasticity. To further investigate the role of NMDA receptors in extinction, we examined the effects of the NMDA antagonist d(-)-3-(2-carboxypiperazine-4-yl)-propyl-1-phosphonic acid (CPP) on the extinction of conditioned freezing and suppression of bar pressing (conditioned emotional response). Rats extinguished normally during a 90 min session in the presence of systemic CPP (10 mg/kg), but were unable to recall extinction learning 24 hr later. This suggests that an NMDA-independent form of plasticity supports short-term extinction memory, but NMDA receptors are required for consolidation processes leading to long-term extinction memory. Surprisingly, extinction learned in the presence of CPP was recalled normally when tested 48 hr after training, suggesting a delayed consolidation process that was able to improve memory in the absence of further training. Delayed consolidation involves NMDA receptors because CPP injected on the rest day between training and test prevented 48 hr recall of extinction learned under CPP. Control experiments showed that the effect of CPP on memory consolidation was not caused by state-dependent learning or reduced expression of freezing under CPP. These findings demonstrate that NMDA receptor activation is critical for consolidation of extinction learning and that this process can be initiated after training has taken place. We suggest that consolidation of extinction involves off-line relearning that reinforces extinction memory through NMDA-mediated plasticity, perhaps in prefrontal-amygdala circuits.

Conditioned fear responses to a tone paired with footshock extinguish when the tone is presented repeatedly in the absence of shock. Rather than erase the tone-shock association, extinction is thought to involve new learning accompanied by inhibition of conditioned responding. Despite much interest in extinction from a clinical perspective, little is known about the neural circuits that are involved. Although the prefrontal cortex has a well established role in the inhibition of inappropriate behaviors, previous reports have disagreed as to the role of the ventromedial prefrontal cortex (vmPFC) in extinction. We have reexamined the effects of electrolytic vmPFC lesions made before training on the acquisition, extinction, and recovery of conditioned fear responses in a 2 d experiment. On Day 1 vmPFC lesions had no effect on acquisition or extinction of conditioned freezing and suppression of bar pressing. On Day 2 sham rats recovered only 27% of their acquired freezing, whereas vmPFC-lesioned rats recovered 86%, which was indistinguishable from a control group that never received extinction. The high recovery in lesioned rats could not be attributed to decreased motivation or altered sensitivity to footshock. vmPFC lesions that spared the caudal infralimbic (IL) nucleus had no effect. Thus, the vmPFC (particularly the IL nucleus) is not necessary for expression of extinction, but it is necessary for the recall of extinction learning after a long delay. These data suggest a role of the vmPFC in consolidation of extinction learning or the recall of contexts in which extinction took place.

In auditory fear conditioning, pairing of a neutral acoustic conditioned stimulus (CS) with an aversive unconditioned stimulus (US) results in an enhancement of neural responses to the CS in the amygdala and auditory cortex. It is not clear, however, whether cortical plasticity governs neural changes in the amygdala or vice versa, or whether learning in these two structures is determined by independent processes. We examined this issue by recording single-cell activity in the auditory cortex (areas Te1, Te1v, and Te3) of freely behaving, amygdalectomized rats using a movable bundle of microwires. Amygdala damage did not affect short-latency (0-50 msec) tone responses, nor did it interfere with conditioning-induced increases of these onset responses. In contrast, lesions of the amygdala interfered with the development of late (500-1500 msec) conditioned tone responses that were not present before conditioning. Furthermore, whereas onset conditioned responses in the control group remained elevated after 30 extinction trials (presentation of CS alone), onset responses in lesioned animals returned to their preconditioning firing level after approximately 10 extinction trials. These results suggest that the amygdala enables the development of long-latency (US anticipatory) responses and prevents the extinction of short-latency onset responses to threatening stimuli. The findings further suggest that auditory cortex cells may participate differently in explicit and implicit memory networks.

To examine the effects of chronic malnutrition on central nervous system function, we used the somatosensory evoked potential to measure the central conduction time of 20 children aged 7-8 y with heights below the third percentile for their age and 20 control children in Honduras. The two groups differed significantly in socioeconomic status, achievement in Bender's neurointegrative test, and hematocrit, but not in birth weight. After median nerve stimulation, the mean central conduction time (interpeak latency between N13 and N20) for the growth-stunted group (6.19 +/- 0.52 ms) did not differ significantly from that of the control subjects (6.30 +/- 0.58 ms), suggesting appropriate myelination and fiber diameter. Somatosensory tracts may escape damage resulting from postnatal dietary deficiencies because myelination in these tracts is almost complete at birth.

Single neurons were recorded in freely behaving rats during fear conditioning from areas of auditory cortex that project to the lateral nucleus of the amygdala (LA). The latency and rate of conditioning and extinction were analyzed, and the results were compared to previous recordings from LA itself. Auditory cortex neurons took more trials to learn, and they responded more slowly than LA neurons within trials. Short-latency plasticity in LA, therefore, reflects inputs from the auditory thalamus rather than the auditory cortex. Unlike LA cells, some auditory cortex cells showed late conditioned responses that seemed to anticipate the unconditioned stimulus, while others showed extinction-resistant memory storage. Thus, rapid conditioning of fear responses to potentially dangerous stimuli depends on plasticity in the amygdala, while cortical areas may be particularly involved in higher cognitive (mnemonic and attentional) processing of fear experiences.

The first laboratory of neurophysiology was installed in the medical school of the University of Honduras during the 1992-1993 academic year. The goal of the project was to improve the teaching of physiology in the medical curriculum and to establish a neuroscience research laboratory able to address Honduran needs. In addition to a computer learning facility and wet labs in neurophysiology for medical students, an independent research program that focused on social problems in the country (for example, the effects of malnutrition on the developing central nervous system) was developed, paving the way for the first graduate program in physiology in Honduras. Funded by a Fulbright Lectureship Grant, the shoe-string budget was augmented by donations of equipment by colleagues. This first-hand account describes the planning and implementation of the project, covering both expected and unexpected problems and successes. An update on the progress of the lab after two years of independent operation is also described.

The lateral nucleus of the amygdala (LA) is the first site in the amygdala where the plasticity underlying fear conditioning could occur. We simultaneously recorded from multiple LA neurons in freely moving rats during fear conditioning trials in which tones were paired with foot shocks. Conditioning significantly increased the magnitude of tone-elicited responses (often within the first several trials), converted unresponsive cells into tone-responsive ones, and altered functional couplings between LA neurons. The effects of conditioning were greatest on the shortest latency (less than 15 ms) components of the tone-elicited responses, consistent with the hypothesis that direct projections from the auditory thalamus to LA are an important link in the circuitry through which rapid behavioral responses are controlled in the presence of conditioned fear stimuli.