Behavioural effects of GABA-agonists and antagonists infused in the mesencephalic reticular formation - deep layers of superior colliculus.
Unilateral infusion of GABA-receptor antagonists (picrotoxin, bicuculline) in the mesencephalic reticular formation-deep layers of the superior colliculus (MRF-DLSC) elicits tight head-to-tail contralateral posturing but not active circling. Bilateral infusion of the GABA antagonists in the MRF-DLSC elicits compulsive gnawing and biting but not licking or sniffing. Infusion of GABA-receptor agonists (muscimol, THIP) in the MRF-DLSC while producing only minor or no motor or behavioural effects, drastically altered apomorphine effects; thus, unilateral infusion of muscimol resulted i tight, head-to-tail ipsiversive circling while bilateral infusion of muscimol converted the apomorphine-syndrome from stereotypy of high-intensity into pure compulsive forward locomotion devoid of sniffing. The results indicate that GABAergic mechanisms in the MRF-DLSC are of primary importance in the expression of motor and behavioural syndromes arising from the striatum.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D004292:Dominance, Cerebral / Q000502:physiology; D008636:Mesencephalon / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D009118:Muscimol / Q000494:pharmacology; D010852:Picrotoxin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012154:Reticular Formation / Q000502:physiology*; D012640:Seizures / Q000139:chemically induced; D013477:Superior Colliculi / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D001640:Bicuculline; D009118:Muscimol; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid; C017069:bicuculline methiodide