GABAergic modulation of axonal conduction in the developing rat retinotectal pathway.
The effect of gamma-aminobutyric acid (GABA) on nerve conduction was investigated in the developing rat optic nerves in vitro. Antidromic compound action potentials (CAP) were suppressed by GABA, with increasing attenuation in older preparations. Enhancement of CAP amplitude using bicuculline was observed in postnatal days 4-5 suggesting the presence of endogenous GABA activity. Our findings suggest that the role of electrical activity in the refinement of the retinotectal projection could be limited by the GABAergic action on axonal conduction.
Developmental Neurobiology Group, Research School of Biological Sciences, Australian National University, Canberra, Australia.
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D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D001640:Bicuculline / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000166:cytology; D018756:GABA Antagonists / Q000494:pharmacology; D009431:Neural Conduction / Q000502:physiology*; D009900:Optic Nerve / Q000166:cytology / Q000196:embryology / Q000254:growth & development; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000166:cytology* / Q000196:embryology / Q000254:growth & development; D013477:Superior Colliculi / Q000166:cytology* / Q000196:embryology / Q000254:growth & development; D014795:Visual Pathways; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D018756:GABA Antagonists; D005680:gamma-Aminobutyric Acid; D001640:Bicuculline