Electrophysiological Analysis of GABA and Glycine Action on Neurons of the Catfish Retina

• 영문명: Electrophysiological Analysis of GABA and Glycine Action on Neurons of the Catfish Retina
• 발행기관: 대한생리학회
• 저자명: Bai, Sun-Ho Jung, Chang-Sub Lee, Sung-Jong
• 간행물 정보: 『대한생리학회지』제27권 제2호, 163~174쪽, 전체 12쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1993.12.31

영문 초록

Vertebrate retinal neurons, like brain tracts farm complex synaptic relations in the enter and inner plexiform layers which ape equivalent to the central nervous system nuclei. The effects of γ-aminobutyric acid(GABA) and glycine on retinal neurons were explored to discern the mechanisms of action of neurotransmitters. Experiments were performed in the superfused retina-eyecup preparation of the channel catfish, Ictalurus punctatus, using intracellular electrophysiological techniques. The roles of GABA and glycine as inhibitory neurotransmitters are well established in the vertebrate retina. But, we found that the depolarizing action of GABA and glycine on third-order neurons in the catfish retina. GABA and glycine appeared to act on retinal ueurons based on the observations that (1) effects on photoreceptors were not observed, (2) horizontal cells were either hyperpolarized (~ 33%) or depolarized (~ 67%), (3) bipolar cells were all hyperpolarized (4) amacrine and ganglion cells were either hyperpolarized (~ 37%) or depolarized (~ 63%), (5) GABA and glycine may be working to suppress presynaptic inhibition. The results suggest that depolarization of third-order neurons by GABA and glycine is due to at least two mechanisms; a direct postsynaptic effect and an indirect effect. Therefore, in the catfish retina, a mechanism of presynaptic inhibition or disinhibition including the direct postsynaptic effect may exist in the third-order neurons.

키워드

Catfish retinal neurons Eyecup GABA Glycine Disinhibition