Caffeine, the most widely consumed psychostimulant drug, acutely stimulates motor behaviour and enhances dopamine agonists actions whilst chronically it induces tolerance to either caffeine- or dopamine agonist-induced motor activating effects. The present study examined whether subchronic caffeine administration (15 mg=kg, on alternate days for 14 days) induces enduring modifications in caffeine- and amphetaminemediated motor activity. To this end, motor activation and rotational behaviour stimulated by either caffeine or D-amphetamine (0.5, 2 mg=kg), given 3 days after the last caffeine administration, were evaluated in neurologically intact and unilaterally 6-hydroxydopamine-lesioned rats respectively. Subchronic caffeine resulted in an increase in caffeine-induced motor and turning behaviour. Furthermore, caffeine pretreatment potentiated the motor effects of amphetamine in both intact and 6-hydroxydopamine-lesioned rats. These results suggest that subchronic caffeine treatment results in an enhancement of its motor stimulant effects, rather than in tolerance, and induces neuroadaptive facilitatory changes in dopamine transmission.
SUBCHRONIC-INTERMITTENT CAFFEINE AMPLIFIES THE MOTOR EFFECTS OF AMPHETAMINE IN RATS
PINNA A;MORELLI M
2006
Abstract
Caffeine, the most widely consumed psychostimulant drug, acutely stimulates motor behaviour and enhances dopamine agonists actions whilst chronically it induces tolerance to either caffeine- or dopamine agonist-induced motor activating effects. The present study examined whether subchronic caffeine administration (15 mg=kg, on alternate days for 14 days) induces enduring modifications in caffeine- and amphetaminemediated motor activity. To this end, motor activation and rotational behaviour stimulated by either caffeine or D-amphetamine (0.5, 2 mg=kg), given 3 days after the last caffeine administration, were evaluated in neurologically intact and unilaterally 6-hydroxydopamine-lesioned rats respectively. Subchronic caffeine resulted in an increase in caffeine-induced motor and turning behaviour. Furthermore, caffeine pretreatment potentiated the motor effects of amphetamine in both intact and 6-hydroxydopamine-lesioned rats. These results suggest that subchronic caffeine treatment results in an enhancement of its motor stimulant effects, rather than in tolerance, and induces neuroadaptive facilitatory changes in dopamine transmission.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
