Affordable Access

Publisher Website

Cholinergic mechanisms in the ventrolateral medullary depressor area

Authors
Journal
Brain Research
0006-8993
Publisher
Elsevier
Publication Date
Volume
501
Issue
2
Identifiers
DOI: 10.1016/0006-8993(89)90652-5
Keywords
  • Afdx-116
  • Blood Pressure
  • Cis-Methyldioxolane
  • Heart Rate
  • M1And M2Muscarinic Receptor
  • Mcn-A343
  • Pirenzepine
  • Wistar Rat

Abstract

Abstract Cardiovascular actions of cholinergic agonists in the ventrolateral medullary depressor area (VLDA) were investigated. Microinjections (0.2–1.6 nmol/site) of an M 2 muscarinic receptor agonist ( cis-methyldioxolane; CD) into the VLDA decreased blood pressure (33–71 mm Hg) and heart rate (11–62 beats/min). Microinjections of AFDX-116 (a specific blocker for M 2 receptors), but not those of pirenzepine (a specific blocker for M 1 receptors), prevented the depressor responses induced by CD. Unilateral microinjections of CD (0.3 nmol) into the VLDA also elicited depressor and bradycardic effects which were blocked by microinjections of bicuculline methiodide (200 pmol) into the ipsilateral ventrolateral medullary pressor area (VLPA). Bilateral vagotomy did not alter the depressor and bradycardic actions of CD in the VLDA. McN-A343 (2–3 nmol/site), an M 1 receptor agonist, failed to evoke any response when microinjected into the VLDA. These results indicate that muscarinic receptors of the M 2 type are present in the VLDA. Activation of the latter by cholinergic agonists results in depressor and bradycardic responses. These responses are mediated via the VLPA.

There are no comments yet on this publication. Be the first to share your thoughts.