Dissecting the stress circuits of the paraventricular nucleus of the thalamus

National Institute Of Mental Health

Investigators

Linked publications, trials & patents

Abstract

Over the course of FY21, we concluded and published two independent research studies that collectively highlighted a previously neglected role for the paraventricular nucleus of the thalamus (PVT) in driving goal-directed behaviors. The first study showed that the PVT is part of a brain circuit that promotes food seeking behavior in response to chemically induced hypoglycemia (Beas et al., 2020). Specifically, this study implicated PVT projections to the nucleus accumbens (NAc)a ventral-striatal region previously linked to goal-directed behaviorsin food seeking behavior. Notably, our findings highlighted the PVT as a critical node in the control of glucose homeostasis and answered long-standing questions regarding the neural mechanisms that underlie this process. In the second study we discovered that, in addition to guiding appetitive goal-directed behavior, PVT projections to the NAc also control active avoidance, a goal-directed instrumental defensive response (Ma et al, 2021). Moreover, this study demonstrated a role for the PVT in mediating the selection of opposing defensive strategies. Collectively, by highlighting important contribution of the PVT to both appetitive and defensive instrumental behaviors, the studies we conducted and published during FY21 support recent proposals that the PVT is a candidate region for guiding behavioral decisions amid motivational conflicts (e.g., approach-avoidance). Elucidating the mechanisms that contribute to this behavior selection process is at the center of our ongoing research efforts. Our overarching goal is to achieve a comprehensive understanding of how the neuronal circuits of the PVT contribute to adaptive behavior. We believe that developing such framework will allow us to identify potential links between genetic and/or environmentally driven modifications of these circuits and the emergence of maladaptive behavioral states.