Res Vestib Sci.  2012 Dec;11(4):131-137.

Expression of Metabotropic Glutamate Receptors in the Medial Vestibular Nucleus Following Acute Hypotension in Rats

• Choi MA
• Kim N
• Park SE
• Park BG
• Kim MS
• Park BR

Abstract

BACKGROUND AND OBJECTIVES
Acute hypotension induces expression of c-Fos protein and phosphorylated extracellular signal-regulated kinase (pERK), and glutamate release in the vestibular nuclei. Expression of c-Fos protein and pERK is mediated by the excitatory neurotransmitter, glutamate. In this study, the signaling pathway of glutamate in the vestibular nuclei following acute hypotension was investigated.
MATERIALS AND METHODS
Expression of metabotropic glutamate receptors (mGluRs) was measured by Western blotting in the medial vestibular nucleus following acute hypotension in rats.
RESULTS
Expression of pGluR1 Ser831, a subtype of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, peaked at 30 minutes after acute hypotension insult, and expression of pNR2B, a subtype of N-methyl-D-aspartate (NMDA) receptors, peaked at 2 hours after acute hypotension insult. Acute hypotension induced expression of Homer1a and group I mGluR in the medial vestibular nucleus. Expression of mGluR1 and mGluR5 peaked at 6 hours following acute hypotension insults.
CONCLUSION
These results suggest that afferent signals from the peripheral vestibular receptors, resulting from acute hypotension insult, are transmitted through group I mGluRs as well as AMPA and NMDA receptors in the vestibular system.

Keyword

Metabotropic glutamate receptor; Ionotropic glutamate receptor; Homer1a; Medial vestibular nucleus; Acute hypotension

MeSH Terms

alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
Animals
Blotting, Western
Glutamic Acid
Hypotension
N-Methylaspartate
Neurotransmitter Agents
Phosphotransferases
Rats
Receptors, Metabotropic Glutamate
Receptors, N-Methyl-D-Aspartate
Vestibular Nuclei
Glutamic Acid
N-Methylaspartate
Neurotransmitter Agents
Phosphotransferases
Receptors, Metabotropic Glutamate
Receptors, N-Methyl-D-Aspartate
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid