Involvement of dopamine, N-methyl-D-aspartate and sigma receptor mechanisms in methamphetamine-induced anticipatory activity rhythm in rats.

Daily injection of methamphetamine (MAP) increased the locomotor activity and produced the development of MAP-induced anticipatory activity on the next withdrawal day. Daily restricted feeding also causes a feeding-associated anticipatory activity rhythm. The importance of catecholaminergic neurons has been suggested in the manifestation of a feeding-associated corticosterone rhythm. In our study, we examined the role of dopaminergic neurons in the development of MAP-induced anticipatory activity. The development of MAP-induced anticipatory activity was blocked by coadministration of dopamine D2 receptor antagonists such as YM-09151-2 and sulpiride, the D1 receptor antagonist SCH23390 and haloperidol weak D1/D2 receptor antagonist, but not by clozapine. The anticipatory activity increase was reproduced by daily injection of the D2 receptor agonist quinpirole as well as moderately by the D1 receptor agonist SKF38393. Moreover, MAP-induced anticipation was blocked by coadministration of the N-methyl-D-aspartate receptor antagonist MK-801 or sigma ligands rimcazol and NE-100. Our results suggest that activation of the dopaminergic system, especially via D2 receptors may be required for the development of MAP-associated anticipatory activity increases and that N-methyl-D-aspartate receptors and sigma receptor mechanisms are also involved in the development of this behavior.