Nigral infusions of muscimol or bicuculline facilitate seizures in developing rats.

Abstract

The substantia nigra (SN) appears to be a crucial site involved in the modification of seizures. The aim of this study was to elucidate the role of the GABA nigral system in the expression of seizures by comparing the effects of multiple doses of a GABA agonist (muscimol) and a GABA antagonist (bicuculline methobromide) on the development of flurothyl seizures in 16-day-old rat pups. The drugs were infused bilaterally either in the SN or dorsal to the SN. An additional group of pups were infused with bicuculline in the corpus striatum. Results indicate that both drugs facilitated the development of seizures in a dose-related manner when infused into the SN. Infusions of muscimol dorsal to the SN had no effect on seizure latencies while infusions of bicuculline dorsal to SN or corpus striatum still increased the susceptibility of rat pups to seizures. The data suggest that only the effects of muscimol on seizures are specific for the SN and that early in life muscimol may exert its proconvulsant effects via a different receptor site or mechanism than bicuculline.

• Authors: E F Sperber, B Y Wong, J N Wurpel, S L Moshé
• Journal: Brain research (Brain Res) Vol. 465 Issue 1-2 Pg. 243-50 (Dec 15 1987) ISSN: 0006-8993 [Print] Netherlands
• PMID: 3440204 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Muscimol
• Bicuculline

Topics

• Animals
• Bicuculline (administration & dosage, toxicity)
• Dose-Response Relationship, Drug
• Muscimol (administration & dosage, toxicity)
• Rats
• Rats, Inbred Strains
• Seizures (chemically induced)
• Substantia Nigra (drug effects)