Article date: 1989/2/20
PubMed ID: 2713664
Journal name: Brain research (ISSN: 0006-8993)
Recent evidence suggests that the substantia nigra (SN) may be involved in the modification of various experimental epilepsy models. We determined the role of gamma-aminobutyric acid (GABA)ergic activity of the SN and the target sites of SN efferents, the pedunculopontine nucleus (PPN) and superior colliculus (SC), in pentylenetetrazol-induced seizures in rats. Bilateral administration of a GABA agonist (muscimol) into the SN significantly reduced seizure severity; its administration into the PPN significantly augmented seizure severity; administration into the SC did not alter the seizure severity. On the other hand, infusion of a GABA antagonist (bicuculline) into the PPN revealed a protective effect against seizures. Our findings indicate that the nigral GABAergic projections to the PPN play an important role in seizure propagation. Thus, PPN neurons may be a possible target site of nigral output modulating seizure propagation.
Author List: Okada R, Negishi N, Nagaya H
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Muscimol; gamma-Aminobutyric Acid; Pentylenetetrazole; Bicuculline;
Mesh terms: Animals; Bicuculline/pharmacology; Male; Muscimol/pharmacology; Pentylenetetrazole; Pons/drug effects; Rats; Rats, Inbred Strains; Seizures/chemically induced; Substantia Nigra/drug effects; Superior Colliculi/drug effects; gamma-Aminobutyric Acid/metabolism;