Korean J Physiol Pharmacol.  2004 Aug;8(4):181-185.

Activation of Vestibular Neurons Projecting to Autonomic Brain Stem Nuclei Following Acute Hypotension in Rats

• Choi DO
• Yon CI
• Choi MA
• Park BR
• Kim MS

Abstract

Extracellular regulated protein kinase1/2 (pERK1/2) is one of the major regulatory factors for transcription of the c-fos oncogene in neurons. The purpose of this study was to evaluate the expression of phosphorylated ERK1/2 within the vestibular nuclei (VN) of rats following acute arterial hypotension. Following the acute arterial hypotension induced by rapid hemorrhage, a significant number of pERK1/2-immunoreactive neurons appeared bilaterally in the caudal aspect of the medial and inferior VN. No labeling of pERK1/2 was observed in the lateral VN. The peak expression of pERK1/2 in these nuclei occurred within 5 min after hemorrhage. However, in bilaterally labyrinthectomized rats, the appearance of pERK1/2-immunoreactive neurons was eliminated in the VN. Western blot confirmed the effect of bilateral labyrinthectomy on pERK1/2 protein expression in the medial vestibular nucleus 5 min after hemorrhage. These results suggest that, following acute hypotension, afferent signals from the peripheral vestibular receptors are required for activation of ERK 1/2 in the VN.

Keyword

Vestibular nucleus; Hypotension; pERK 1/2; Labyrinthectomy

MeSH Terms

Animals
Blotting, Western
Brain Stem*
Brain*
Hemorrhage
Hypotension*
Neurons*
Oncogenes
Rats*
Vestibular Nuclei