DIFFERENTIAL ROLE OF DOPAMINE-RECEPTORS ON MOTOR ASYMMETRIES OF NIGRO-STRIATAL LESIONED ANIMALS THAT ARE REM-SLEEP DEPRIVED

Recently, we have shown that rapid eye movement sleep deprivation (REM -SD) in animals with lesions of the nigro-striatal pathway facilitates turning behavior and such increase still occurred even in the presenc e of dopaminergic grafts. The objective of this work was to determine which DA receptors are preferentially involved. The results showed tha t the D-2 receptor antagonist sulpiride decreases significantly turnin g behavior of lesioned animals, with no effect whatsoever of the D-1 a ntagonist SCH 23390. When lesioned animals were REM sleep deprived, th e D-1 but not the D-2 receptor antagonist prevented the increase of tu rning induced by REM-SD. This work suggests that the increase of post- synaptic supersensitivity induced by REM-SD in nigro-striatal lesioned animals is mediated by D-1 receptors.