Biology subjects

Tsai, V.

Publications and source records attributed to Tsai, V..

5 recordsLinked to original sources

bioRxiv2025

Experience-Dependent Plasticity of Thalamoprefrontal Circuitry Characterizes Learning Across Species

Learning is an adaptive process which is thought to require precise coordination among multiple brain regions over time. Thalamoprefrontal circuitry is central to multiple domains of cognitive control and executive function, yet its evolution during learning is not characterized. In this study, we explored thalamoprefrontal circuit signaling in mice and connectivity dynamics in humans over the course of learning a homologous psychomotor task. In mice, we targeted a genetically encoded Ca2+indicator to the mediodorsal-prefrontal (MdT-dmPFC) projection and used fiber photometry to record synaptic dorsomedial PFC (dmPFC) activity. As learning sessions progressed, all mice demonstrated a decrease in reaction time (RT) performance on successful trials (p<0.001). In concomitant synaptic MdT-dmPFC circuit activity across sessions, we observed a significant increase in activity during the anticipatory (p<0.01) and reward retrieval (p<0.01) periods, and a non-significant trend towards an increase in preparatory activity (p<0.15). However, following the learning period, during task re-exposure, we observed a significant shift in circuit activity, away from anticipatory (p<0.001) and towards the preparatory period (p<0.001) over the course of re-exposure sessions. Furthermore, we observed an emergence of a learner (decrease in RT) and a non-learner group (increase in RT) during the task re-exposure period. Over the course of a single analogous task session in humans, we also observed a learner and a non-learner group. When analyzing the thalamoprefrontal regional connectivity dynamics of early and late trials for learners, we observed a significant increase in low frequency and decrease in high frequency synchrony (connectivity tilt) in thalamoprefrontal pathways during preparatory and anticipatory periods. Interestingly, pairwise interactions specifically between the anterior corona radiata (ACR) and superior frontal gyrus (SFG), the human homolog to the genetically targeted MdT-dmPFC circuitry in mice, in fact demonstrated a robustly opposite connectivity tilt effect distinguishing learners from non-learners (Cohens d > 2). Overall, these findings may provide cross-species evidence of novel, conserved thalamoprefrontal circuit mechanisms of adaptive learning.

neuroscience↗

bioRxiv2025

Concerted actions of distinct serotonin neurons orchestrate female pup care behavior

In many mammalian species, female behavior towards infant conspecifics changes across reproductive stages. Sexually naive females interact minimally or aggressively with infants, whereas the same animals exhibit extensive care behavior, even towards unrelated infants, after parturition1-6. Here, we discovered that two distinct sets of serotonin neurons collectively mediate this dramatic transition in maternal behavior--serotonin neurons projecting to the medial preoptic area (mPOA) promote pup care in mothers, whereas those projecting to the bed nucleus of the stria terminalis (BNST) suppress pup interaction in virgin female mice. Disrupting serotonin synthesis in either of these subpopulations or stimulating either subpopulation is sufficient to toggle pup-directed behavior between that displayed by virgin females and that of lactating mothers. In virgin female mice, the first pup interaction triggers an increase in serotonin release in BNST but a decrease in mPOA. In mothers, serotonin activity becomes greatly elevated in mPOA during pup interactions. Acute interruption of serotonin signaling locally in either mPOA or BNST disrupts the stage-dependent switch in pup care. Together, these results highlight how functionally distinct serotonin subpopulations orchestrate social behaviors appropriate for a given reproductive state, and suggest a circuit logic for how a neuromodulator coordinates adaptive behavioral changes across life stages.

neuroscience↗

bioRxiv2025

Recombination alters the furin cleavage site in novel bat-borne HKU5-CoV-2 coronavirus

HKU5-CoV-2 is a new bat-infecting coronavirus phylogenetically related to MERS-CoV. It has recently been confirmed that HKU5-CoV-2 can enter human cells and organoids in vitro via the ACE2 receptor, raising concerns about its pandemic potential due to zoonotic spillover. Whether recombination has an influence on HKU5-CoV-2 is completely unclear to date. Here we report the first evidence of HKU5-CoV-2 viral recombination, in association with mutations at the receptor binding domain (RBD) and S1/S2 furin cleavage site (FCS) of the spike protein. Using linkage disequilibrium and haploblock analysis, we identified that 167 recombination hotspots and 27 haploblocks. SNP23016/23043/23064/23156/23193/23285 at the RBD and SNP23833/23847 at the FCS are recombinant hotspots. Our results suggest that recombination may lead to the substitution at RBD residue 498 (Thr498Val/Val498Thr, Thr498Ile/Ile498Thr), which Thr498 directly contacts the ACE2 receptor. Recombination also causes Ser723 deletion/insertion and Ser729Ala substitution at the FCS. These mutations could affect host tropism and change furin cleavage activity. Our results indicate that recombination has played a critical role in HKU5-CoV-2 evolution and infectivity.

microbiology↗

bioRxiv2022

Dynorphin / kappa-opioid receptor regulation of excitation-inhibition balance toggles afferent control of prefrontal cortical circuits in a pathway-specific manner.

The medial prefrontal cortex (mPFC) controls emotional behaviors and cognition via connections with limbic excitatory afferents that engage various intra-mPFC inhibitory motifs The mPFC dynorphin (Dyn) / kappa-opioid receptor (KOR) system regulates affect and cognition and is implicated in neuropsychiatric disorders. However, its unclear how neuropeptides in the mPFC, including the Dyn / KOR system, control excitatory and inhibitory circuit motifs integral in information processing. Here, we provide a circuit-based framework wherein selective KOR expression in mPFC afferents or within mPFC feedforward and feedback inhibitory circuits gates how distinct limbic afferent inputs control mPFC neurons. Dyn/KOR signaling directly decreases the ability of KOR-expressing afferent inputs to drive mPFC cell activity. Dyn/KOR signaling also suppresses afferent-driven recruitment of inhibitory sub-networks via several mechanisms, disinhibiting KOR-negative excitatory afferent control of mPFC ensembles. Thus, the Dyn/KOR system toggles which afferent input controls mPFC circuits, providing mechanistic insights into the role of neuropeptides in shaping mPFC function. HighlightO_LIPathway-specific KOR expression confers selective filtering of mPFC afferents by dynorphin C_LIO_LIEndogenous dynorphin release gates KOR-expressing inputs to both dynorphin-expressing and lacking mPFC neurons C_LIO_LIDynorphin / KOR modulation reveals parallel channels within amygdalo-cortical and cortical-cortical circuits C_LIO_LIDynorphin disinhibits mPFC pyramidal neurons via KOR-mediated suppression of distinct inhibitory circuit motifs that preferentially impact SST-mediated feedforward inhibition C_LIO_LIDynorphin / KOR signaling biases afferent control of mPFC principal cells away from KOR-positive and towards KOR-negative afferent inputs C_LI

neuroscience↗

bioRxiv2022

Dynamic Sex Differences in Reactive and Appetitive Aggression

Aggression is an evolutionarily conserved, adaptive component of social behavior. Studies in male mice illustrate that aggression is influenced by numerous factors including the degree to which an individual finds aggression rewarding and will work for access to attack and subordinate mice. While such studies have expanded our understanding of the molecular and circuit mechanisms of male aggression very little is known about female aggression, owed in part to limited availability of valid mouse models in females. Here we use an ethologically relevant model of male vs. female aggression by pair housing adult male and female outbred CFW mice with opposite sex cage mates. We assess reactive (defensive) aggression in the resident intruder (RI) test and appetitive (rewarding) aggression in the aggression conditioned place preference (CPP) and operant self-administration (SA) tests. Our results show dramatic sex differences in both qualitative and quantitative aspects of reactive vs. appetitive aggression. Males exhibit more wrestling and less investigative behavior during RI, find aggression rewarding and will work for access to a subordinate to attack. Females exhibit more bites, alternate between aggressive behaviors and investigative behaviors more readily during RI, however, they do not find aggression to be rewarding or reinforcing. These results establish sex differences in aggression in mice, providing an important resource for the field to better understand the circuit and molecular mechanisms of aggression in both sexes.

neuroscience↗