Biology subjects

Falconnier, C.

Publications and source records attributed to Falconnier, C..

3 recordsLinked to original sources

bioRxiv2026

Acetylcholine drives astrocytic JAK2-STAT3 signaling to modulate male-to-female approach behavior

Astrocytes are essential regulators of neural circuits and behavior, sensing synaptic activity and modulating plasticity through diverse intracellular mechanisms. However, the contribution of astrocyte transcription factor-based cascades, linking external stimuli to long-term transcriptional programs, is currently misunderstood. Here we show that the JAK2-STAT3 signaling plays a critical role in male-to-female social behavior. Hence, in male mice, exposure to estrus females rapidly and selectively induces STAT3 signaling in ventral hippocampal astrocytes. Surprisingly, this induction is not driven through canonical cytokine signaling but by septo-hippocampal cholinergic inputs acting through 7 nicotinic acetylcholine receptors (7nAChR). Astrocytic 7nAChR-JAK2-STAT3 signaling in turn modulates vCA1 pyramidal neuron activity and is required for context-appropriate male approach behavior. These findings reveal a previously unsuspected cellular pathway integrating neuromodulatory inputs and transcription factor-based signaling to shape male behavioral response depending on female receptivity.

neuroscience↗

bioRxiv2025

Sex-divergent brain epigenetic reprogramming by chronic opioids

Opioid use disorder (OUD) is a chronic condition that exhibits sex differences in prevalence, symptoms and treatment. Yet, the epigenetic mechanisms underlying these differences remain largely unknown. Here, we investigated the nucleus accumbens, a key brain region in OUD, to define the multiomic consequences of chronic morphine exposure in male and female mice. We profiled DNA methylation, five histone post-translational modifications, and their transcriptional effects at bulk and cell-type-specific levels. Despite comparable tissue organization and neurophysiological responses to morphine, epigenetic adaptations occurred at highly sex-specific genomic loci. These adaptations nevertheless followed common mechanistic principles, acting at similar gene features and transcription factor binding sites across sexes. Strikingly, they converged on overlapping genes, biological functions, and co-expression modules, and partially recapitulated transcriptional signatures of OUD in men and women. Therefore, our findings uncover a profound epigenetic sex divergence that mediates convergent biological dysregulation, and highlight opportunities for developing improved therapeutic strategies tailored to sex-specific mechanisms.

neuroscience↗

bioRxiv2022

Functional genomic mechanisms of opioids: a systematic review of animal and human studies

In the past two decades, over-prescription of opioids for pain management has driven a steep increase in opioid use disorder (OUD) and death by overdose, exerting a dramatic toll on western countries. OUD is a chronic relapsing disease associated with a lifetime struggle to control drug consumption, suggesting that opioids trigger long-lasting brain adaptations, notably through functional genomic and epigenomic mechanisms. Current understanding of these processes, however, remain scarce, and have not been previously reviewed systematically. To do so, the goal of the present work was to synthesize current knowledge on genome-wide transcriptomic and epigenetic mechanisms of opioid action, in primate and rodent species. Using a prospectively registered methodology, comprehensive literature searches were completed in PubMed, Embase, and Web of Science. Of the 2709 articles identified, 73 met our inclusion criteria and were considered for qualitative analysis. Focusing on the 5 most studied nervous system structures (nucleus accumbens, frontal cortex, whole striatum, dorsal striatum, spinal cord; 44 articles), we also conducted a quantitative analysis of differentially expressed genes, in an effort to identify a putative core transcriptional signature of opioids. Only one gene, Cdkn1a, was consistently identified in eleven studies, and globally, our results unveil surprisingly low consistency across published work, even when considering most recent single-cell approaches. Analysis of putative sources of variability detected significant contributions from species, brain structure, duration of opioid exposure, strain, time-point of analysis, and batch effects, but not type of opioid. To go beyond those limitations, we leveraged threshold-free methods to illustrate how genome-wide comparisons may generate new findings and hypotheses. Finally, we discuss current methodological development in the field, and their implication for future research and, ultimately, better care.

neuroscience↗