백서 고속핵 미각영역에서 gamma-aminobutyric acid의 효과 = Effects of gamma-aminobutyric acid on the gustatory nucleus tractus solitarius in rats

다국어 초록 (Multilingual Abstract)

Gamma-aminobutyric acid (GABA) is known as an inhibitory neurotransmitter in the neurons of the central nervous system. However, its detailed action mechanisms in the rostral gustatory zone of the nucleus tractus solitarius (rNTS) have not been established. The present study was aimed to investigate the distribution, role and action mechanisms of GABA in rNTS. Presence of GABA ergic neurons was examined by immunohistochemistry and membrane potentials were recorded by whole cell recordings in isolated brain slices of the rat medulla. GABA-containing neurons were present in the gustatory nucleus tractus solitarius. Superfusion of GABA resulted in a concentration-dependent reduction in input resistance in the neurons in rNTS. The change in input resistance was accompanied by membrane hyperpolarization. The spontaneous activity and action potential elicited in response to a depolarizing pulse were diminished by GABA. Superfusion of the slices with either GABA_A agonist, muscimol, GABA_B agonist, baclofen or GABA_C agonist, TACA, decreased input resistance and reduced the nerve activity in association with membrane hyperpolarization.
It is suggested that inhibitory signals play a role in sensory processing by the rNTS, in that GABA actions occur through activation of GABA_A, GABA_B, and GABA_C receptors.
These results suggest that GABA has an inhibitory effect on the rNTS through an activation of GABA_A, GABA_B, and GABA_C receptors and that the GABAergic inhibition probably plays an important role in sensory processing by the rNTS.

목차 (Table of Contents)

• Ⅰ. 서 론
• Ⅱ. 실험방법
• Ⅲ. 실험결과
• Ⅳ. 고 찰
• Ⅴ. 결 론
• 참고문헌
• 영문초록