The neural substrates of apomorphine-stimulated locomotor activity following denervation of the nucleus accumbens.
Efferent fibers from the nucleus accumbens (N.Acc.) to the substantia innominata and lateral preoptic region (SI/LPO) are believed to be essential for the supersensitive locomotor response to apomorphine in rats following 60HDA-induced denervation of the N.Acc., since destruction of cells within the SI/LPO eliminates this supersensitive response. In the present study, the neurochemical properties of this efferent projection were investigated. Injection of muscimol, a GABA agonist, directly into the SI/LPO produced a dose-dependent decrease in supersensitive locomotor activity at doses that did not alter baseline locomotion. Higher doses of muscimol actually produced a prolonged locomotor activation in all animals. These results suggest that the locomotor activation following stimulation of supersensitive dopamine receptors within the N.Acc. may involve a decrease in GABAergic activity at the level of the SI/LPO.
D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002421:Caudate Nucleus / Q000032:analysis; D004298:Dopamine / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D006892:Hydroxydopamines / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009118:Muscimol / Q000494:pharmacology; D009476:Neurons, Efferent / Q000502:physiology; D009638:Norepinephrine / Q000032:analysis; D009714:Nucleus Accumbens / Q000032:analysis / Q000502:physiology*; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000502:physiology; D012686:Septal Nuclei / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D006892:Hydroxydopamines; D011963:Receptors, GABA-A; D015102:3,4-Dihydroxyphenylacetic Acid; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D016627:Oxidopamine; D001058:Apomorphine; D004298:Dopamine; D009638:Norepinephrine