Parvalbumin

Neural activity in the cortex exhibits a wide range of timescales, allowing animals to respond to rapidly changing sensory stimuli while maintaining information in working memory. Recent studies show how top-down inputs representing locomotive state modulates these timescales differently across visual areas in mice. In particular, the sign of correlations between speed and neural activity varies by region, highlighting the interplay between bottom-up sensory inputs, top-down pathways and connectivity motifs in shaping cortical dynamics. In addition, cortical circuits comprise a large diversity

Neural activity in the cortex exhibits a wide range of timescales, allowing animals to respond to rapidly changing sensory stimuli while maintaining information in working memory. The timescales of neural activity are not only affected by bottom-up sensory inputs, but also by top-down inputs originating from corticocortical and neuromodulatory pathways. In addition, cortical circuits comprise a large diversity of cell types connected in non-random ways, which are the subject of profound plasticity dynamics. Due to this complexity, understanding how top-down projections affect the timescales of

The basolateral amygdala (BLA) is increasingly recognized as a key regulator of depression and anxiety-like behaviors. However, the specific contribution of individual BLA neurons to these behaviors remains poorly understood. Building on our previous study, which demonstrated increased activity in glutamatergic BLA neurons in response to aversive stimuli and that enhancing inhibition in the BLA can alleviate depressive-like behaviors, we investigated the role of individual GABAergic neurons (BLAGABA) in depressive and anxiety-like phenotypes. Our findings indicate that BLAGABA neurons show dec

The processing of sensory information by the neocortex is at the heart of conscious perception and is known to involve a dynamic interaction between synaptically connected GABAergic inhibitory interneurons (INs) and excitatory principal neurons (PNs). One hypothesis is that sensory feature encoding in PNs is supported by different IN types performing specific functional roles. Here we address this hypothesis in the mouse thermal cortex. The thermal system is a fundamental pathway required for accurate object identification, pain perception and body temperature regulation and one that is highly

Hearing loss in the elderly has been associated with cognitive impairments and an increased risk of dementia. Social withdrawal due to difficulties in verbal interaction may play an important role. Previous research on deafened rats, ruling out language as a potential confounding factor, showed only initial and mild cognitive deficits during learning, whereas electrophysiological recordings in the prefrontal cortex revealed compromised neuronal activity to some extent. The present study tested whether hearing loss would lead to altered expression of the GABA and dopamine (DA) systems in key re

Hippocampal Interneurons are heavily myelinated but show differences in composition/distribution and myelin function. Contactin-2 (CNTN2 or TAG-1), an adhesion molecule of the immunoglobulin superfamily, expressed in glia and axons, organizes the juxtaparanodal region of myelinated fibers and clusters voltage-gated potassium channels under the myelin sheath. CNTN2 has a dynamic spatial and temporal expression and is implicated in migration during development as well as in neuropathology (multiple sclerosis, AD). We have shown that a significant population of hippocampal GABAergic interneurons

…fast-spiking interneurons expressing parvalbumin (INPV). These neurons are surrounded by a specialized extracellular matrix, the perineuronal nets (PNNs) which regulate their functions a

Autism spectrum disorder is characterized by a wide range of symptoms, including impairments in social interactions, communication, and emotion-related behavior. In this study we aimed to uncover the changes of inhibitory basket cell outputs in the prefrontal cortex and basolateral amygdala, regions that play a central role in the expression of core symptoms in autistic behaviors.We observed that valproate treatment at E12.5 resulted in a decrease in ultrasound vocalizations in the pups (n=12) and an increase in tactile sensitivity assessed by the von Frey test in comparison to controls (n=13)

Schizophrenia is a major disabling psychiatric disease, significantly impacts patients' social functioning. The lateral septum (LS), a brain region connecting the cortex to the hypothalamus and crucial for regulating affect and social behaviors, is implicated in schizophrenia. We hypothesized that specific populations of LS neurons regulating social interactions are dysregulated during schizophrenia and leveraged the Df(16)A+/- mouse model of schizophrenia to test our hypothesis. This model contains the human 22q11 microdeletion, which in humans, confers a 30% probability to develop schizophre

…stainings (calbindin, calretinin, parvalbumin, nonphosphorylated neurofilament H /SMI32/ among others

…Many of these interneurons express parvalbumin (PV), a calcium bindingprotein, and their somata and proximal dendrites are surrounded by a specialized region ofextracellular matrix, the perineuronal nets (PNNs). Recent studies have

…Somatostatin (SOM) and Parvalbumin (PV) positive GABAergic neurons are two major classes of interneurons in the hippocampus, providing strong dendritic and peri-somatic inhibition to excitatory neurons, respectively. It is well known that exposure of mice to an enriched environment (EE) reliably increases performance on hippocampus-dependent learning and memory tasks. However, the mechanisms underlying the behavioral improvements an

…PL, including pyramidal cells (Pyr), parvalbumin- (PV+), somatostatin- (Sst+), and vasoactive intestinal peptide- (VIP+) expressing interneurons, in processing information about familiar and novel social stimuli.We employed chemo/optogenetics alongside automated behavioral testing in Eco-HAB®, an RFID-based system for ecologically relevant assessment of social behavior in group-housed mice. This

Communication between neurons and glial cells are crucial to establish and maintain brain function. Some of these interactions are activity-dependent, yet it remains unexplored how acute changes in neuronal activity affect neuron-to-glial dynamics.Here, we used excitatory and inhibitory designer receptors exclusively activated by designer drugs (DREADD) based chemogenetic methods to study the effects of acute manipulations of a subpopulation of layer 5 cortical projection and dentate gyrus neurons in adult (Rbp4Cre) mouse brain after 90 minutes. We validated changes in activity with in vitro p

…GABAergic interneurons positive for parvalbumin (PV-GaIs) and somat

We have previously communicated that multisession epidural direct current anodic stimulation (ES) of the auditory cortex (AC) preserves hearing thresholds (Fernández del Campo, 2024) and the loss of neurons in the olivary brainstem efferent system (Alvarado, 2024) after aging. Although it is known that the descending pathway is the main effector for hearing preservation in our age-related hearing loss (ARHL) model, intrinsic mechanisms through which ES preserves cortical regulation must be analyzed. Our hypothesis is that our ES protocol regulates AC activity and prevents alterations in inhibi

In this study we have investigated the plasticity-related changes observed in the medial prefrontal cortex (mPFC) of a dual-hit model of schizophrenia developed in rats. The dual-hit model combines an injection of non-competitive NMDA receptor antagonist MK-801 at P7 and 8 weeks of postweaning social isolation. The model was developed in both male and female rats. At P90 RNA sequencing (RNAseq) was conducted on the prefrontal cortex. Differential expressed genes (DEGs) and enriched categories were validated in silico via MAGMA using GWAS summary statistics of the Psychiatric Genomics Consortiu

The hippocampus plays a pivotal role in the formation of episodic memories, facilitating spatial navigation and detection of novel stimuli. Within this structure, the dentate gyrus (DG) is crucial for discriminating novel from familiar content. Despite GABAergic inhibitory interneurons (INs) being increasingly recognized to participate to the hippocampal computation by controlling the activity of principal cells, the specific mechanisms by which they contribute to the encoding of episodic memories remain elusive. This study explores how interneurons (INs) representations of spatial context are

Rapid eye movement (REM, also called paradoxical) sleep correlates with enhanced cellular activity in region-specific thalamo-cortical circuits and subcortical structures including the hippocampus, midbrain or hypothalamus. This REM sleep specific neuronal activity is hypothesized to promote structural plasticity and provide a window for the consolidation of contextual and emotional memories previously acquired during wakefulness, yet the underlying mechanism remains unclear.Amongst the cortical structures, the activity of neurons located in the retrosplenial cortex (RSC) is increased during R

…showed the immunoreactivity for parvalbumin

According to the World Health Organization, there were over 340 million obese or overweight children and adolescents worldwide in 2016. Western diet consumption, based on refined sugars and high-fat foods, leads to obesity and negative effects on the brain, resulting in cognitive impairments even before changes in body weight. This is especially concerning for young people, since brain development, neurogenic processes, and neuronal maturation occur during this life period. Knowing this, our study aimed to analyze the effects of high-caloric diets on the hippocampus, particularly on the gamma-

Parvalbumin-positive GABAergic interneurons (PV-INs) provide inhibitory control of excitatory neuron activity, coordinate circuit function, and regulate behavior and cognition. PV-INs are uniquely susceptible to loss and dysfunction in traumatic brain injury (TBI) and epilepsy but the cause of this susceptibility is unknown. One hypothesis is that PV-INs use specialized metabolic systems to support their high-frequency action potential firing and that metabolic stress disrupts these systems, leading to their dysfunction and loss. Metabolism-based therapies can restore PV-IN function after inju

…the loss of GluN2A signaling impacts parvalbumin-positive (PV) GABAergic interneuron function in hippocampus. Grin2a knockout mice have 33% more PV cells in CA1 compared

Cortical circuits process information by rich recurrent interactions between excitatory neurons and inhibitory interneurons. One of the prime functions of interneurons is to stabilize the circuit by feedback inhibition, but the level of specificity on which inhibitory feedback operates is not fully resolved. We hypothesized that inhibitory circuits could enable separate feedback control loops for different synaptic input streams, by means of specific feedback inhibition to different neuronal compartments. To investigate this hypothesis, we adopted an optimization approach. Leveraging recent ad