Ontogeny of the motor inhibitory role of dopamine D(3) receptor subtype in rats.
We have examined the motor responses to the dopamine D(3) receptor-preferring agonist, S(+)-(4aR,10bR)-3,4,4a, 10b-tetrahydro-4-propyl-2H,5H-1-benzopyranol[4,3-b]-1,4-oxazin+ ++-9-ol ((+)-PD128,907), by non-habituated male rats during postnatal development. (+)-PD128,907 (0.025 and 0.1 mg/kg) increased motor activity (rearing, motility and locomotion) in 14-day-old rats without inducing oral stereotypies. However, in 21-, 28- and 70-day-old rats, (+)-PD128,907 caused a significant reduction in motor activity. This reduction was most pronounced in 70-day-old rats. In addition, the stimulatory effects of (+)-PD128,907 in 14-day-old rats were fully blocked by the dopamine D(3) receptor antagonist 5,6-dimethoxy-2-(di-u-propylamino) indan (U99194A). These results suggest that the motor inhibition mediated by the activation of the dopamine D(3) receptors develops between the second and the third postnatal weeks.
Heijtz
R D
RD
Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
Ogren
S O
SO
Fuxe
K
K
D000367:Age Factors; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology*; D007189:Indans / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010078:Oxazines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D050637:Receptors, Dopamine D3
D001578:Benzopyrans; D018491:Dopamine Agonists; C493595:Drd3 protein, rat; D007189:Indans; D010078:Oxazines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C062458:3,4,4a,10b-tetrahydro-4-propyl-2H,5H-(1)benzopyrano(4,3-b)-1,4-oxazin-9-ol; C086335:(5,6-dimethoxyindan-2-yl)dipropylamine