Deakin University
Browse

File(s) under permanent embargo

Hypothalamic paraventricular nucleus neurons regulate medullary catecholamine cell responses to restraint stress

journal contribution
posted on 2004-10-04, 00:00 authored by C Dayas, K Buller, Trevor DayTrevor Day
Both physical and psychological stressors recruit catecholamine cells (CA) located in the ventrolateral medulla (VLM) and the nucleus of the solitary tract (NTS). In the case of physical stressors, this effect is initiated by signals that first access the central nervous system at or below the level of the medulla. For psychological stressors, however, CA cell recruitment depends on higher structures within the neuraxis. Indeed, we have recently provided evidence of a pivotal role for the medial amygdala (MeA) in this regard, although such a role must involve a relay, as MeA neurons do not project directly to the medulla. However, some of the MeA neurons that respond to psychological stress have been found to project to the hypothalamic paraventricular nucleus (PVN), a structure that provides significant input to the medulla. To determine whether the PVN might regulate medullary CA cell responses to psychological stress, animals were prepared with unilateral injections of the neurotoxin ibotenic acid into the PVN (Experiment 1), or with unilateral injections of the retrograde tracer wheat germ agglutinin-gold (WGA-Au) into the CA cell columns of the VLM or NTS (Experiment 2). Seven days later, animals were subjected to a psychological stressor (restraint; 15 minutes), and their brains were subsequently processed for Fos plus appropriate cytoplasmic markers (Experiment 1), or Fos plus WGA-Au (Experiment 2). PVN lesions significantly suppressed the stress-related induction of Fos in both VLM and NTS CA cells, whereas tracer deposits in the VLM or NTS retrogradely labeled substantial numbers of PVN cells that were also Fos-positive after stress. Considered in concert with previous results, these data suggest that the activation of medullary CA cells in response to psychological stress may involve a critical input from the PVN.

History

Journal

Journal of comparative neurology

Volume

478

Issue

1

Pagination

22 - 34

Publisher

Wiley

Location

London, England

ISSN

0021-9967

eISSN

1096-9861

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2004, Wiley-Liss

Usage metrics

    Research Publications

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC