Cocaine-induced psychomotor sensitization and microglia activation in nucleus accumbens and striatum

BARTOS M; IRIBARREN P; CANCELA L

Huerta Grande

Congreso; XXVII Congreso Anual SAN; 2012

Sociedad Argentina de Investigacion en Neurociencia

Repeated administration of cocaine induces psychomotor sensitization, characterized by an augmented locomotor response to a subsequent cocaine challenge and neuronal changes including alterations in the plasticity within the nucleus accumbens (NAc) and striatum (CPu). Microglia cells are resident cells in the brain that become functionally activated in response to injury and diseases. However, it has not been described how the microglia is involved in the psychomotor sensitization and the participation of enkephalinergic system. Male C57B/6J mice were daily treated with cocaine and vehicle for 9 days followed by a cocaine challenge on day 21 of the treatment. The immunohistochemistry was performed in the areas of interest using CD11b and met-ENK antibodies. Cytokines were measured by RT-PCR. In the control treatment microglia cells have small soma and ramified processes. Repeated administration of cocaine induces morphological changes of microglial cells indicative of cell activation and also increased production of pro-inflammatory cytokines such as TNF-α. We observed co-localization of met-ENK with CD11b in microglia. These preliminary results could be a key to better understanding the role of immunological signaling system in drugs addiction which might become in a new therapeutic target.