Performance- and task-dependent effects of the dopamine D1/D5 receptor agonist SKF 38393 on learning and memory in the rat.
Dopamine D(1)/D(5) receptor agonists may enhance cognition by mimicking dopamine's neurophysiological actions on the processes underlying learning and memory. The present study examined the task- and performance- dependence of the cognitive effects of a partial agonist at dopamine D(1)/D(5) receptors, SKF 38393 [(+/-)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol hydrobromide], in rats. Spatial working memory was assessed in a T-maze, spatial reference memory in a water maze and habituation learning in a novel environment, a hole board. The muscarinic acetylcholine receptor antagonist scopolamine (1.5 mg/kg, i.p.) was used to cause an impairment of performance of these learning tasks. Administration of SKF 38393 (6 mg/kg, i.p.) alone had no significant effect on spontaneous alternation in the T-maze, latency to escape to a hidden platform in the water maze or the habituation of spontaneous behaviour in the hole board. In contrast, in scopolamine-treated rats, whereas SKF 38393 prevented the scopolamine-induced deficit in the T-maze, it exacerbated the impairment in the water maze and did not significantly alter the disruption of habituation. These results suggest that dopamine D(1)/D(5) receptor activation has performance- and task-dependent effects on cognitive function.
Amico
Francesco
F
Department of Pharmacology and Therapeutics, Trinity College, Dublin 2, Ireland.
Spowart-Manning
Laura
L
Anwyl
Roger
R
Rowan
Michael J
MJ
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology*; D000818:Animals; D018491:Dopamine Agonists / Q000494:pharmacology*; D007858:Learning / Q000187:drug effects*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D018721:Muscarinic Agonists / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D050641:Receptors, Dopamine D5 / Q000819:agonists*; D012601:Scopolamine / Q000494:pharmacology
D018491:Dopamine Agonists; D018721:Muscarinic Agonists; D050641:Receptors, Dopamine D5; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D012601:Scopolamine