GABA as an inhibitory transmitter in the pigeon isthmo-tectal pathway.
In the present investigation, the effects of inhibitory amino acids and their antagonists were tested on isthmo-tectal projection in the pigeon. The majority of superficial tectal cells are inhibited following stimulation of the parvocellular division of nucleus isthmi. A smaller portion of tectal cells showed excitatory responses followed by an inhibitory period. Both inhibitory mechanisms are blocked by the specific gamma-aminobutyric acid (GABA)-antagonist bicuculline but not by strychnine. Our results support the idea that GABA acts as an inhibitory neurotransmitter in the pigeon isthmo-tectal pathways.
Felix
D
D
Division of Neurobiology, University of Berne, Switzerland.
Wu
G Y
GY
Wang
S R
SR
D000818:Animals; D001479:Basal Ganglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D001640:Bicuculline / Q000494:pharmacology; D010856:Columbidae / Q000502:physiology*; D004594:Electrophysiology; D007478:Iontophoresis; D018377:Neurotransmitter Agents / Q000502:physiology*; D013331:Strychnine / Q000494:pharmacology; D013477:Superior Colliculi / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D014795:Visual Pathways / Q000187:drug effects / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D018377:Neurotransmitter Agents; D005680:gamma-Aminobutyric Acid; D013331:Strychnine; D001640:Bicuculline