Ontogenetic changes in [3H]-spiroperidol binding sites in posthatch chick brain.
The ontogenetic development of [3H]-spiroperidol binding sites was measured in the optic tectum, cerebellum, forebrain base, and forebrain roof of 1-, 4-, and 16-day-old chicks. In the chick optic tectum and cerebellum both the density and the total number of [3H]-spiroperidol binding sites increased from 4- to 16-days-posthatch, but no significant differences were found in either brain area across the initial four posthatch days. In the forebrain base, [3H]-spiroperidol receptor density and total binding increased significantly between 1- and 4-days-posthatch, but at 16-days-posthatch there was a slight decrease in receptor density. Binding sites in the forebrain roof were minimal at all ages. As expected, saturation experiments yielded curvilinear plots indicating the presence of high- and low-affinity binding sites. The high-affinity sites probably reflect dopamine D-2 receptors; whereas, the low-affinity sites may reflect other receptor types, possibly serotonin S-2. These results suggest that large doses of haloperidol, which are normally used in chick behavioral research, may produce behavioral effects by antagonizing multiple receptors.
McDougall
S A
SA
Department of Psychology, University of Kentucky, Lexington 40506.
Neisewander
J L
JL
Bardo
M T
MT
Zolman
J F
JF
D000375:Aging / Q000378:metabolism; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism; D004027:Diencephalon / Q000378:metabolism; D011954:Receptors, Dopamine / Q000378:metabolism; D013134:Spiperone / Q000378:metabolism*; D013477:Superior Colliculi / Q000378:metabolism; D013687:Telencephalon / Q000378:metabolism
D011954:Receptors, Dopamine; C031611:spiroperidol receptor; D013134:Spiperone