Abstract representations emerge in human hippocampal neurons during inference.

Humans have the remarkable cognitive capacity to rapidly adapt to changing environments. Central to this capacity is the ability to form high-level, abstract representations that take advantage of regularities in the world to support generalization. However, little is known about how these representations are encoded in populations of neurons, how they emerge through learning and how they relate to behaviour.

The representational geometry of emotional states in basolateral amygdala.

Sensory stimuli associated with aversive outcomes cause multiple behavioral responses related to an animal's evolving emotional state, but neural mechanisms underlying these processes remain unclear. Here aversive stimuli were presented to mice, eliciting two responses reflecting fear and flight to safety: tremble and ingress into a virtual burrow. Inactivation of basolateral amygdala (BLA) eliminated differential responses to aversive and neutral stimuli without eliminating responses themselves, suggesting BLA signals valence, not motor commands.

Visuospatial information foraging describes search behavior in learning latent environmental features.

In the real world, making sequences of decisions to achieve goals often depends upon the ability to learn aspects of the environment that are not directly perceptible. Learning these so-called latent features requires seeking information about them. Prior efforts to study latent feature learning often used single decisions, used few features, and failed to distinguish between reward-seeking and information-seeking.

Low Cost Gastroschisis Silo for Sub-Saharan Africa: Testing in a Porcine Model.

Background: Gastroschisis mortality in sub-Saharan Africa (SSA) remains high at 59-100%. Silo inaccessibility contributes to this disparity. Standard of care (SOC) silos cost $240, while median monthly incomes in SSA are < $200.

Prelimbic cortex drives discrimination of non-aversion via amygdala somatostatin interneurons.

The amygdala and prelimbic cortex (PL) communicate during fear discrimination retrieval, but how they coordinate discrimination of a non-threatening stimulus is unknown. Here, we show that somatostatin (SOM) interneurons in the basolateral amygdala (BLA) become active specifically during learned non-threatening cues and desynchronize cell firing by blocking phase reset of theta oscillations during the safe cue. Furthermore, we show that SOM activation and desynchronization of the BLA is PL-dependent and promotes discrimination of non-threat.

Partitioning variability in animal behavioral videos using semi-supervised variational autoencoders.

Recent neuroscience studies demonstrate that a deeper understanding of brain function requires a deeper understanding of behavior. Detailed behavioral measurements are now often collected using video cameras, resulting in an increased need for computer vision algorithms that extract useful information from video data. Here we introduce a new video analysis tool that combines the output of supervised pose estimation algorithms (e.

Symptom profiles and treatment status of older adults with chronic post-traumatic stress disorder.

Objective: Failure to diagnose and treat post-traumatic stress disorder (PTSD) may help explain the substantial disability, increased cognitive decline, and adverse health outcomes suffered by older adults with this disorder. To evaluate this possibility, we examined symptom differences among older and younger individuals with PTSD and measured the frequency with which older adults receive standard of care treatment.

Methods: Clinician-Administered PTSD Scale for DSM (CAPS) scores were compared between younger and older adults with PTSD.

The COVID-19 Pandemic as a Traumatic Stressor: Mental Health Responses of Older Adults With Chronic PTSD.

Objective: Individuals with post-traumatic stress disorder (PTSD) who experience additional traumas or stressful life events may undergo symptomatic worsening, but no data exist on whether exposure to the COVID-19 pandemic in a high infection area worsens mental health among older adults with chronic PTSD.

Methods: Seventy-six older adults (N = 46 with PTSD and N = 30 trauma-exposed comparison subjects [TE]) for whom prepandemic data were available were interviewed between April 1 and May 8, 2020 to quantify depressive (Hamilton Rating Scale for Depression [HRSD]) and PTSD symptom (Post-traumatic Stress Disorder Checklist [PCL-5]) levels. Group differences in baseline characteristics as well as pre-post pandemic symptom levels were examined, and participant characteristics were assessed as moderators of symptom change.

The Geometry of Abstraction in the Hippocampus and Prefrontal Cortex.

The curse of dimensionality plagues models of reinforcement learning and decision making. The process of abstraction solves this by constructing variables describing features shared by different instances, reducing dimensionality and enabling generalization in novel situations. Here, we characterized neural representations in monkeys performing a task described by different hidden and explicit variables.

Benzodiazepines: it's time to return to the evidence.

We propose that discussions of benzodiazepines in the current psychiatric literature have become negatively biased and have strayed from the scientific evidence base. We advocate returning to the evidence in discussing benzodiazepines and adhering to clear definitions and conceptual rigour in commentary about them.

Low-dimensional dynamics for working memory and time encoding.

Our decisions often depend on multiple sensory experiences separated by time delays. The brain can remember these experiences and, simultaneously, estimate the timing between events. To understand the mechanisms underlying working memory and time encoding, we analyze neural activity recorded during delays in four experiments on nonhuman primates.

Multidisciplinary Development of a Low-Cost Gastroschisis Silo for Use in Sub-Saharan Africa.

Background: Gastroschisis silos are often unavailable in sub-Saharan Africa (SSA), contributing to high mortality. We describe a collaboration between engineers and surgeons in the United States and Uganda to develop a silo from locally available materials.

Methods: Design criteria included the following: < $5 cost, 5 ± 0.

Diagnostic and Predictive Neuroimaging Biomarkers for Posttraumatic Stress Disorder.

Background: Comorbidity between posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) has been commonly overlooked by studies examining resting-state functional connectivity patterns in PTSD. The current study used a data-driven approach to identify resting-state functional connectivity biomarkers to 1) differentiate individuals with PTSD (with or without MDD) from trauma-exposed healthy control subjects (TEHCs), 2) compare individuals with PTSD alone with those with comorbid PTSD+MDD, and 3) explore the clinical utility of the identified biomarkers by testing their associations with clinical symptoms and treatment response.

Methods: Resting-state magnetic resonance images were obtained from 51 individuals with PTSD alone, 52 individuals with PTSD+MDD, and 76 TEHCs.

The contribution of nonhuman primate research to the understanding of emotion and cognition and its clinical relevance.

Psychiatric disorders are often conceptualized as arising from dysfunctional interactions between neural systems mediating cognitive and emotional processes. Mechanistic insights into these interactions have been lacking in part because most work in emotions has occurred in rodents, often without concurrent manipulations of cognitive variables. Nonhuman primate (NHP) model systems provide a powerful platform for investigating interactions between cognitive operations and emotions due to NHPs' strong homology with humans in behavioral repertoire and brain anatomy.

Selective serotonin reuptake inhibitors and benzodiazepines in panic disorder: A meta-analysis of common side effects in acute treatment.

Background: Benzodiazepines (BZs) and selective serotonin reuptake inhibitors (SSRIs) are effective in the pharmacologic treatment of panic disorder (PD). However, treatment guidelines favor SSRIs over BZs based on the belief that BZs are associated with more adverse effects than SSRIs. This belief, however, is currently supported only by opinion and anecdotes.