ELECTROPHYSIOLOGICAL AND MORPHOLOGICAL CHARACTERISTICS OF FACIAL NUCLEUS IN RAT

,; ,; ,; ,

Journal of the Korean Academy of Pediatric Dentistry 2000;27(3):400-409.
Published online August 31, 2000.

ELECTROPHYSIOLOGICAL AND MORPHOLOGICAL CHARACTERISTICS OF FACIAL NUCLEUS IN RAT

¹
²
³

흰쥐 안면신경핵 세포의 전기생리학적 및 형태학적 특성

최병주¹, 조진화¹, 배용철², 김영진³

¹경북대학교 치과대학 치과약리학교실
²경북대학교 치과대학 구강해부학교실
³경북대학교 치과대학 소아치과학교실

Abstract

This study used in vivo intracellular and extracellular field potential recording to evaluate the intrinsic membrane properties and connection pattern within facial nucleus. 1. There were four subdivisions of medial, intermediate, lateral, and dorsolateral in facial nucleus. 2. Principal cells in the facial nucleus was recorded from and filled with neurobiotin in anesthetized rats. The extent of their dendrites and the characteristics of cell body were examined. 3. Principal cells had a large amplitude action potential and afterhyperpolarization was followed a single action potential. 4. The response from facial motonucleus to electrical stimulation of the facial nerve was mainly a monophasic wave, with a latency of 1 msec, which was assumed to reflect antidromic activation of facial motoneurons. In some of rats the response in addition showed late components at a latency of about 7-8 msec, but its amplitude was small. 5 Most of cells exhibited accommodation of spike discharge upon depolarization of membrane by 0.8 nA for 400 ms. Our results support the hypothesis that there normally are weak connections between different parts of the facial motonucleus to explain pathophysiology of hemifacial spasm and facial naive paralysis.

Key Words: Facial nucleus, Synapse, Membrane properties, Facial nerve paralysis, Hemifacial spasm