title: Involvement of the substantia innominata/ventral pallidum complex in transmitting forelimb muscular rigidity evoked from the nucleus accumbens in rats.
abstract: In the present study it was investigated whether muscular rigidity elicited from the nucleus accumbens could be transmitted via the substantia innominata/ventral pallidum (SI/VP) complex. For this purpose rats were equipped with cannulae aimed at the nucleus accumbens and/or the SI/VP, and with electrodes in the triceps muscle of the forelimb. In the first set of experiments it was found that the GABA agonist muscimol (10-25 ng/0.5 microliters) dose-dependently increased tonic EMG activity upon injection into the SI/VP region. The GABA antagonist bicuculline (50 ng/0.5 microliters) antagonized the effects of muscimol (25 ng/0.5 microliters). In the second set of experiments it appeared that the increase in tonic EMG activity induced by haloperidol (1000 ng/0.5 microliters) injected into the nucleus accumbens was antagonized by subsequent injection of bicuculline (25 ng/0.5 microliters) into the SI/VP complex. These data suggest that the SI/VP complex may be one station through which the muscular rigidity elicited from the nucleus accumbens is transmitted to lower brain structures.
authors: Psychoneuropharmacological Research Unit, Catholic University Nijmegen, The Netherlands.
authors: R
authors: R
authors: van den Bos
authors: A R
authors: AR
authors: Cools
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000502:physiology*; D001640:Bicuculline / Q000494:pharmacology; D004566:Electrodes; D004576:Electromyography; D005552:Forelimb; D006220:Haloperidol / Q000494:pharmacology; D007267:Injections; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D009127:Muscle Rigidity / Q000209:etiology*; D009714:Nucleus Accumbens / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012686:Septal Nuclei / Q000502:physiology*; D013377:Substantia Innominata / Q000502:physiology*
chemical_list: D009118:Muscimol; D006220:Haloperidol; D001640:Bicuculline