Psychopharmacological investigations of a lead-induced long-term XXXX in monkeys.

@entity1617 @entity73 @entity5591 @entity4944
This study investigated pharmacological manipulations of the cholinergic ( @entity1617 ) and dopaminergic (DA) transmitter systems in monkeys with a long-term lead-induced @entity73 on delayed spatial alternation (DSA). Both @entity1617 and DA have been found to be affected by developmental lead exposure and to be involved with performance on spatial learning and memory tasks. The lead-induced deficit in performance accuracy on DSA persisted throughout the 2 years of this experiment, which ended more than 8 years after the end of the postnatal lead exposure. Acute administration of agonists and antagonists of the @entity1617 and DA systems did not elicit differential effects from the lead-exposed and control groups in terms of DSA per cent correct performance. The @entity1617 antagonist, @entity5591 , caused a dose-related decline in performance in both groups. Significant amelioration of the lead-induced DSA deficit was achieved by chronic treatment with the DA agonist, L-dopa. After withdrawal from L-dopa, the lead-related deficit reappeared. Improvement in performance of the lead-treated group was also seen after chronic @entity4944 administration, but this effect was not significant. These data implicate DA mechanisms in the long-lasting cognitive effects of developmental lead exposure. The alleviation of the deficit with chronic administration of a DA precursor points to a possible line of treatment for the cognitive effects of developmental lead exposure.
