GABAergic fibers from substantia nigra pars reticulata modulate escape behavior induced by midbrain central gray stimulation.
Electrical stimulation of microinjection of GABA antagonists into the dorsal periaqueductal gray (DPAG) produces escape behavior. In order to determine whether the nigrocollicular gabaergic fibers exert some control over this behavior, rats bearing kainic acid lesion of the substantia nigra pars reticulata were submitted to microinjections of bicuculline or electrical stimulation of the DPAG at the escape threshold. Rats thus treated exhibited a significant decrease in the escape threshold while bicuculline increased the expression of flight behavior. These results suggest an inhibitory control of gabaergic fibers from the substantia nigra pars reticulata on aversive behavior induced by DPAG stimulation.
Coimbra
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NC
Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brasil.
Leão-Borges
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PC
Brandão
M L
ML
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology*; D004558:Electric Stimulation; D004924:Escape Reaction / Q000187:drug effects*; D018756:GABA Antagonists; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000187:drug effects*
D018756:GABA Antagonists; D007608:Kainic Acid; D001640:Bicuculline