Res Vestib Sci.  2018 Dec;17(4):142-151. 10.21790/rvs.2018.17.4.142.

Application of Tetrode Technology for Analysis of Changes in Neural Excitability of Medial Vestibular Nucleus by Acute Arterial Hypotension

• Kim Y
• Koo H
• Park BR
• Moon SJ
• Yang SB
• Kim MS

• KMID: 2436245
• DOI: http://doi.org/10.21790/rvs.2018.17.4.142

Abstract

OBJECTIVES
Excitability o medial vestibular nucleus (MVN) in the brainstem can be affected by changes in the arterial blood pressure. Several animal studies have demonstrated that acute hypotension results in the alteration of multiunit activities and expression of cFos protein in the MVN. In the field of extracellular electrophysiological recording, tetrode technology and spike sorting algorithms can easily identify single unit activity from multiunit activities in the brain. However, detailed properties of electrophysiological changes in single unit of the MVN during acute hypotension have been unknown.
METHODS
Therefore, we applied tetrode techniques and electrophysiological characterization methods to know the effect of acute hypotension on single unit activities of the MVN of rats.
RESULTS
Two or 3 types of unit could be classified according to the morphology of spikes and firing properties of neurons. Acute hypotension elicited 4 types of changes in spontaneous firing of single unit in the MVN. Most of these neurons showed excitatory responses for about within 1 minute after the induction of acute hypotension and then returned to the baseline activity 10 minutes after the injection of sodium nitroprusside. There was also gradual increase in spontaneous firing in some units. In contrast small proportion of units showed rapid reduction of firing rate just after acute hypotension.
CONCLUSIONS
Therefore, application of tetrode technology and spike sorting algorithms is another method for the monitoring of electrical activity of vestibular nuclear during acute hypotension.

Keyword

Medial vestibular nucleus; Acute arterial hypotension; Tetrode electrode; Spike sorting; Neuronal firing

MeSH Terms

Animals
Arterial Pressure
Brain
Brain Stem
Fires
Hypotension*
Methods
Neurons
Nitroprusside
Rats
Vestibular Nuclei*
Nitroprusside