Neurotensin and dynorphin Bi-Directionally modulate CeA inhibition of oval BNST neurons in male mice.

Neuropeptides are often co-expressed in neurons, and may therefore be working together to coordinate proper neural circuit function. However, neurophysiological effects of neuropeptides are commonly studied individually possibly underestimating their modulatory roles. Here, we triggered the release of endogenous neuropeptides in brain slices from male mice to better understand their modulation of central amygdala (CeA) inhibitory inputs onto oval (ov) BNST neurons. We found that locally-released neurotensin (NT) and dynorphin (Dyn) antagonistically regulated CeA inhibitory inputs onto ovBNST neurons. NT and Dyn respectively increased and decreased CeA-toovBNST inhibitory inputs through NT receptor 1 (NTR1) and kappa opioid receptor (KOR). Additionally, NT and Dyn mRNAs were highly co-localized in ovBNST neurons suggesting that they may be released from the same cells. Together, we showed that NT and Dyn are key modulators of CeA inputs to ovBNST, paving the way to determine whether different conditions or states can alter the neuropeptidergic regulation of this particular brain circuit.