Correlation of behavioural inhibition or excitation produced by bromocriptine with changes in brain catecholamine turnover
Snider, S.R.; Hutt, C.; Stein, B.; Prasad, A.L.; Fahn, S.
Journal of Pharmacy and Pharmacology 28(7): 563-566
1976
ISSN/ISBN: 0022-3573 PMID: 8610 Document Number: 96362
The dopamine agonist, bromocriptine, produced either inhibition or stimulation of motor behavior in rats depending upon the dose and time after administration. Stimulatin of motor activity occurred only with high doses after a 1-2 h delay. Both inhibition and stimulation were associated with decreased turnover of dopamine in the brain. Release of noradrenaline in brain and noradrenaline plus adrenaline in adrenal varied with motor activity. Low doses of bromocriptine inhibit behavior by activating an inhibitory presynaptic receptor, resulting in reduced synthesis and release of dopamine, while high doses cause behavioral excitation by activating the post-synaptic dopamine receptor.