Kolliker-Fuse/Parabrachial Complex PACAP-Glutamate Pathway to the Extended Amygdala Couples Rapid Autonomic and Delayed Endocrine Responses to Acute Hypotension.

ABSTRACT: The calyx of Held is a giant axo-somatic synapse classically confined to the auditory brainstem. We recently identified morphologically similar calyx-like terminals in the extended amygdala (EA) that arise from the ventrolateral parabrachial complex and co-express PACAP, CGRP, VAChT, VGluT1, and VGluT2, targeting PKCδ⁺/GluD1⁺ EA neurons. Here, we asked whether this parabrachial-EA pathway participates in compensation during acute hypotension. In rats given hydralazine (10 mg/kg, i.p.), we quantified Fos protein during an early phase (60 min) and a late phase (120 min). Early after hypotension, Fos surged in a discrete subpopulation of the parabrachial Kölliker-Fuse (KF) region and in the EA, whereas magnocellular neurons of the supraoptic and paraventricular nuclei (S

SUBMITTER: Hernandez VS 

PROVIDER: S-EPMC12692419 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature