Several evidences indicate that the administration of the D1 agonist receptor, SKF increased AMPA receptor insertion in the extra synaptic cell surface, phenomenon associated with the sensitization to cocaine. The aim of the present study was to demostrate the cooperation between D1 and AMPA in the sensitization induced by stress. Specificaly we evaluated the stimulating locomotor properties of cocaine and dopamine release in the nucleus accumbens core (Nacc Core). Male Wistar rats (250-350g) were restrained for two hours, control animals were left undisturbed in their cages. Twenty-one days after this stress episode all animals werw assigned to one of the following experiments: 1)Locomotor activity in response to i)AMPA microinyections (0, 0.1, 0.3 ug/dl) in NAcc Core, ii)the D1 agonist SKF38393 (0, 0.5, 1.0 mg/Kg i.p.), and iii)the association between SKF 0.5mg/Kg and a subumbral dose of AMPA (0.1ug/dl administered 10 minutes later in Nacc Core). 2) Microdialysis: dopamine levels werw determinated by HPLC in NAcc Core in response to three different concentration of AMPA (1.0, 10.0, 100.0 uM) and in the expression of sensitization to cocaine (15mg/kg i.p.) during the perfusion of the AMPA antagonist, CNQX (1nmol), or vehicle. These results clearly show the participation of AMPA the long-lasting sensitization to cocaine following a single restraint stress session. The stimulation of the D1 makes possible the observation of the stimulant effect produced by subumbral doses of AMPA. These results are discussed in the framework of the stimulating effects that the D1 produce in the surface cellular expression of GluR1 (The AMPA subunit) in the stressed animals. Current experiments are attempting to confirm this hypothesis.