Optogenetic study of the projections from the bed nucleus of the stria terminalis to the central amygdala

Abstract

study of the projections from the bed nucleus of the stria terminalis to the central amygdala. J Neurophysiol 114: 2903-2911. First published September 23, 2015 doi:10.1152/jn.00677.2015.-It has been proposed that the central amygdala (CeA), particularly its medial sector (CeM), generates brief fear responses to discrete conditioned cues, whereas the bed nucleus of the stria terminalis (BNST) promotes long-lasting, anxiety-like states in response to more diffuse contingencies. Although it is believed that BNST-CeA interactions determine the transition between short-and long-duration responses, the nature of these interactions remains unknown. To shed light on this question, we used a double viral strategy to drive the expression of channelrhodopsin (ChR2) in BNST cells that project to CeA. Next, using patch-clamp recordings in vitro, we investigated the connectivity of infected cells to noninfected cells in BNST and compared the influence of BNST axons on neurons in the medial and lateral (CeL) parts of CeA. CeA-projecting BNST cells were concentrated in the anterolateral (AL) and anteroventral (AV) sectors of BNST. Dense plexuses of BNST axons were observed throughout CeA. In CeA and BNST, light-evoked excitatory postsynaptic potentials accounted for a minority of responses (0 -9% of tested cells); inhibition prevailed. The incidence of inhibitory responses was higher in CeM than in CeL (66% and 43% of tested cells, respectively). Within BNST, the connections from CeA-projecting to non-CeA-targeting cells varied as a function of the BNST sector: 50% vs. 9% of tested cells exhibited light-evoked responses in BNST-AL vs. BNST-AV, respectively. Overall, these results suggest that via its projection to CeA, BNST exerts an inhibitory influence over cued fear and that BNST neurons projecting to CeA form contrasting connections in different BNST subnuclei.

Resting‐state fMRI effective connectivity between the bed nucleus of the stria terminalis and amygdala nuclei

“…Our finding of a fully interconnected system is in accordance with studies showing a close interaction between amygdala nuclei and BNST (e.g., Been & Petrulis, ; Dong et al, ; Duvarci & Pare, ; Gungor, Yamamoto, & Pare, ). However, a direct comparison between the results from microscopic research and our macroscopically orientated approach is difficult, and further research with detailed biophysically realistic models is required to establish a link between both approaches.…”

A Central Amygdala CRF Circuit Facilitates Learning about Weak Threats

“…In addition to locally projecting CRF neurons described here, the CeA receives input from other brain regions known to contain CRF-producing neurons, including the paraventricular hypothalamus (PVH) (Hernandez et al, 2015) and bed nucleus of the stria terminalis (BNST) (Gungor et al, 2015), that may contribute to threat conditioning at higher US intensities. To determine the extent of input to the CeA from CRF neurons in the PVH and BNST, we quantified projections from these neurons using the Allen Brain Institute Mouse Connectivity Atlas (Oh et al, 2014).…”

Convergence of Sex Differences and the Neuroimmune System in Autism Spectrum Disorder

“…In the rodent the BNST is also sexually dimorphic in both cell number and the size of afferent connections to other regions (46), as well as activation threshold to socially salient stimuli such olfaction and novelty (65) The BNST regulates innate fear responses and social play (66). Both the POA and the BNST have distinct reciprocal connections with the amygdala (67). …”