The paraventricular thalamus provides a polysynaptic brake on limbic CRF neurons to sex-dependently blunt binge alcohol drinking and avoidance behavior

Abstract

Bed nucleus of the stria terminalis (BNST) neurons that synthesize and release the stress neuropeptide corticotropin-releasing factor (CRF) drive binge alcohol drinking and anxiety, behaviors that are primary risk factors for alcohol use disorder (AUD) and comorbid neuropsychiatric diseases more common in women than men. Here, we show that female C57BL/6J mice binge drink more than males and have greater basal BNSTCRF neuron excitability and synaptic excitation. We identified a dense VGLUT2+ glutamatergic synaptic input from the paraventricular thalamus (PVT) that is anatomically similar in males and females. These PVTBNST neurons release glutamate directly onto BNSTCRF neurons but also engage a large BNST interneuron population to ultimately provide a net inhibition of BNSTCRF neurons, and both components of this polysynaptic PVTVGLUT2-BNSTCRF circuit are more robust in females than males. Chemogenetic inhibition of the PVTBNST projection promoted binge alcohol drinking in females without affecting males, and chemogenetic activation of the pathway was sufficient to reduce avoidance behavior in both sexes in anxiogenic contexts. Lastly, we show that withdrawal from repeated binge drinking produces a female-like phenotype in the male PVT-BNSTCRF excitatory synapse without altering the function of PVTBNST neurons per se. Our data describe a complex feedforward inhibitory PVTVGLUT2-BNSTCRF glutamatergic circuit that is more robust in females, plays sex-dependent roles in alcohol drinking and avoidance behavior, and undergoes sex-dependent alcohol-induced plasticity.