Abstract

The area postrema produces sympathoinhibitory responses and enhances baroreflex mediated sympathoinhibition. Since these effects may depend on intact baroreceptors, it has been hypothesized that the area postrema enhances neurotransmission in the nucleus of the solitary tract (NITS), the primary site of baroreceptor afferent termination. Glutamate is thought to be the principal neurotransmitter released by baroreceptor afferents. However, it is unknown if glutamate neurotransmission in the NTS is required for responses elicited by area postrema stimulation. Glutamate acts at both ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mG1uRs) and both are present in the NTS. While iGluRs are necessary for an intact baroreflex, mGluR may modulate synaptic glutamate transmission in the NTS as has been demonstrated in other brain areas. Microinjections of alpha2 antagonists into the NTS abolish area postrema responses. Thus, alpha2 and glutamate receptors may interact in the NTS to mediate area postrema effects. This proposal is designed to examine interactions of glutamate (through iGluRs and mGluRs) and alpha2 receptors during peripheral and central responses elicited by area postrema stimulation.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32HL010166-02
Application #
6183036
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Project Start
2000-04-01
Project End
Budget Start
2000-04-01
Budget End
2001-03-31
Support Year
2
Fiscal Year
2000
Total Cost
$40,936
Indirect Cost

  Institution

Name
University of Missouri-Columbia
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
112205955
City
Columbia
State
MO
Country
United States
Zip Code
65211

  Publications

Byrska-Bishop, Marta; VanDorn, Daniel; Campbell, Amy E et al. (2015) Pluripotent stem cells reveal erythroid-specific activities of the GATA1 N-terminus. J Clin Invest 125:993-1005
Chou, Stella T; Byrska-Bishop, Marta; Tober, Joanna M et al. (2012) Trisomy 21-associated defects in human primitive hematopoiesis revealed through induced pluripotent stem cells. Proc Natl Acad Sci U S A 109:17573-8
Mueller, Patrick J; Foley, C Michael; Hasser, Eileen M (2005) Hindlimb unloading alters nitric oxide and autonomic control of resting arterial pressure in conscious rats. Am J Physiol Regul Integr Comp Physiol 289:R140-7
Mueller, Patrick J; Hasser, Eileen M (2003) Enhanced sympathoinhibitory response to volume expansion in conscious hindlimb-unloaded rats. J Appl Physiol 94:1806-12
Mueller, P J; Cunningham, J T; Patel, K P et al. (2003) Proposed role of the paraventricular nucleus in cardiovascular deconditioning. Acta Physiol Scand 177:27-35