Venue: Centre Broca
Wataru Inoue
Western University, Canada
https://www.schulich.uwo.ca/physpharm//people/faculty/inoue_wataru.html
Invited by Sophie Layé (NutriNeuro)
Title
Neural arithmetic for stress response.
Abstract
The stress response represents a shift in neural operations—from maintaining homeostasis to executing emergency responses—affecting a wide range of behavioral and physiological functions. A classic example is the activation of the hypothalamic-pituitary-adrenal (HPA) axis, which increases systemic glucocorticoid levels from baseline to stress-elevated concentrations. Despite decades of research, the neural mechanisms underlying this transition remain poorly understood.
Using a combination of in vivo and ex vivo electrophysiology in mice, along with computational modeling, we identified a key circuit mechanism that enables rapid transitions in the activity states of corticotropin-releasing hormone (CRH) neurons in the paraventricular nucleus (PVN) of the hypothalamus—critical regulators of the HPA axis. I will present our findings on how local GABAergic feedback circuits tightly constrain the gain (i.e., arithmetic transformation) of CRHPVN neurons under non-stress conditions. Stress removes this inhibitory control, allowing for the robust activation of CRHPVN neurons. Together, our work reveals a neural arithmetic and circuit-level framework for understanding the hormonal stress response.