Neuronal Excitatory Action of GABA on the Pelvic Ganglia
Journal of Korean Neurosurgical Society
; : 145-149, 2004.
Article
in Ko
| WPRIM
| ID: wpr-77479
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WPRO
ABSTRACT
OBJECTIVE: In the central nervous system, gamma-aminobutyric acid (GABA) is well known to act as an inhibitory neurotransmitter by hyperpolarizing postsynaptic neurons through gating GABA-activated Cl- channels. To date, however, the functional roles of GABA remain unclear in the autonomic nervous system. In the present study, we characterize GABA-activated Cl- currents in the neurons of major pelvic ganglia (MPG). METHODS: MPG neurons, located on the lateral surfaces of the prostate gland, from male rats were enzymatically dissociated. Ionic currents were recorded using whole-cell variant patch-clamp technique. Membrane potential was recorded under current clamp mode. Current traces were filterd at 2kHz by using 4-pole Bassel filter in the amplifier. RESULTS: Application of GABA (100micrometer) induced inward currents in the neurons, with holding potentials being maintained below the Cl- equilibrium potential (ECl). The GABA response was concentration-dependent and its reversal potential was close to the theoretical ECl. The GABA-induced Cl- currents were largely blocked by bicuculline (10micrometer, n=5), a GABAA receptor antagonist, but were not affected by 9-AC and niflumic acid, chloride channel blockers. GABA also produced significant membrane depolarization (19mV, n=28). As in the case of the Cl- currents, the GABA-induced depolarizations were largely blocked by bicuculline(10micrometer, n=6), but not by DIDS(50micrometer, n=4), another chloride channel blocker. CONCLUSION: The data suggest that GABAergic roles may be due to it's activation of excitatory GABAA receptors, which are expressed in MPG neurons.
Key words
Full text:
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Index:
WPRIM
Main subject:
Prostate
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Autonomic Nervous System
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Bicuculline
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Central Nervous System
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Niflumic Acid
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Chloride Channels
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Patch-Clamp Techniques
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Neurotransmitter Agents
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Gamma-Aminobutyric Acid
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Ganglia
Limits:
Animals
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Humans
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Male
Language:
Ko
Journal:
Journal of Korean Neurosurgical Society
Year:
2004
Type:
Article