INTERCHANGEABILITY OF GLUTAMATERGIC MECHANISMS IN THE RECONSOLIDATION OF THE COCAINE AND STRESS-INDUCED REINSTATEMENT IN A COCAINE CONDITIONED PLACE PREFERENCE PARADIGM
De Giovanni, Laura Noemi; Virgolini, Miriam Beatriz, Cancela, Liliana Marina.
luli_deyo@yahoo.com.ar
Previous results from our laboratory show that the administration of MK 801, blocks the stress-induced reinstatement in animals conditioned to cocaine in the conditioned place preference paradigm (CPP) and that this blockage is long lasting 3 and 10 days after the first reinstatement in response to a cocaine priming injection (5 mg/kg).
Our goal was to determine if the reconsolidation memory process is involved in the long lasting MK 801 reinstatement blockage. Male Wistar (220-300g) were conditioned with cocaine injections (10-mg/kg ip), and confined to one of two compartments during four alternated drug/vehicle sessions and later was extinguished with successive vehicle associations. In the reinstatement day, a group of animals was immobilized for 30 min, and control group non-stress. Subsequently, all groups were tested in the CPP and, immediately or 3 h after, injected with MK 801 (0,1 mg/kg) or vehicle, and evaluated 3 days after for cocaine-induced reinstatement. We observed that MK 801 administered immediately after the test blocked cocaine-induced reinstatement, but the animals that were injected 3 h after the test did not show this blockage.
These results suggest that there is a common glutamatergic mechanism between cocaine and stress in the reconsolidation.
