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 BNST CRF 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 PVT BNST neurons release glutamate directly onto BNST CRF neurons but also engage a large BNST interneuron population to ultimately provide a net inhibition of BNST CRF neurons, and both components of this polysynaptic PVT VGLUT2 -BNST CRF circuit are more robust in females than males. While chemogenetic inhibition of the general PVT VGLUT2 neuron population suppressed binge alcohol drinking in both sexes, chemogenetic inhibition specifically of the PVT BNST projection promoted this behavior in females without affecting males; 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-BNST CRF excitatory synapse without altering the function of PVT BNST neurons per se. Our data describe a complex and unique behavioral role of the feedforward inhibitory PVT VGLUT2 -BNST CRF glutamatergic circuit that is more robust in females and undergoes sex-dependent alcohol-induced plasticity. Fig. 1: Females display higher binge alcohol drinking and have greater BNST CRF neuron excitation. a,Average 2-hr alcohol consumption across cycles of the Drinking in the dark (DID) binge drinking paradigm showing higher binge drinking in females than males (n = 10 male mice, 10 female mice). Two-way RM-ANOVA: main effect of sex (F1,18 = 21.62, *** P = 0.0002) and cycle (F4,73 = 6.34, P = 0.0002, not indicated), but no interaction (P > 0.05); direct comparisons within-cycle show sex differences on cycle 2 (t15.8 = 1.58, adjusted *P = 0.037), cycle 5 (t16.3 = 4.71, adjusted **P = 0.001), and cycle 6 (t14.5 = 4.96, adjusted **P = 0.001), with trends on cycle 3 (t17.9 = 2.32, adjusted $ P = 0.063) and cycle 4 (t13.9 = 2.67, adjusted $ P = 0.054). b, Schematic of whole-cell patch clamp recordings of CRF+ neurons in the BNST (BNST CRF neurons, left) and representative 10x confocal image of a coronal BNST section from a CRF-Cre x Ai9 reporter (CRF-reporter) mouse. c, Proportion of BNST CRF neurons sampled that fire in their basal state is greater in females than males (n = 10 male mice, 18 cells; 8 female mice, 19 cells). d-f, spontaneous excitatory and inhibitory synaptic transmission in male and female BNST CRF neurons (males: n = 8 mice, 17 cells; females: n = 8 mice, 21 cells; unpaired ttests). d, Top: representative traces of spontaneous excitatory postsynap...

Sex-specific regulation of binge drinking, social, and arousal behaviors by subcortical serotonin 5HT2creceptor-containing neurons

“…This is somewhat concordant with findings in BNST neurons expressing corticotrophin releasing factor (CRF), a subset of which express 5HT 2c (Marcinkiewcz et al, 2016). In these neurons, binge alcohol consumption significantly increases the proportion of male cells that are in a depolarization block such that they begin to resemble the proportions observed in females (Levine et al, 2021).…”

Involvement of Lateral Habenula Dysfunction in Repetitive Mild Traumatic Brain Injury-Induced Motivational Deficits

“…We found that although the mean sE/I amplitude and frequency in LHb neurons were not significantly different in mTBI and sham mice, mTBI resulted in significant shifts in cumulative probability curves of sE/I ratios (Figure 1 C-G, Kolmogorov-Smirnov tests, p<0.0001). Using the same data points for sEPSC and sIPSC amplitude and frequency, we also calculated and generated the mean, histogram, and cumulative probability curves of synaptic drive ratios in LHb neurons from sham and mTBI mice which incorporated all the properties of sEPSC and sIPSCs including amplitude, charge transfer and frequency 34 . While the mean synaptic drive ratios did not differ between sham and mTBI mice, mTBI resulted in a significant rightward shift in the cumulative probability curves of synaptic drive ratio suggesting that mTBI increased the overall excitatory synaptic drive onto LHb neurons (Figure 1H-I, Kolmogorov-Smirnov tests, p<0.0001).…”

Corticotropin-releasing factor neurons in the bed nucleus of the stria terminalis exhibit sex-specific pain encoding in mice

“…While our findings highlight the use of in vivo calcium dynamics in BNST CRF neurons to understand pain, we acknowledge that the mechanisms contributing to sex-specific encoding remain to be determined. Recent evidence for sex-dependent excitatory transmission and synaptic facilitation in BNST CRF neurons suggests that highly active glutamatergic synapses in female mice prevent increases in excitatory tone that males are otherwise susceptible to 47 . Such differences in intrinsic excitability have major implications on how we interpret relative changes in calcium transients, since we measure these outputs by (i) normalizing pixels within each field-of-view (ΔF/F) and (ii) comparing nociceptive responses to baseline activity.…”