050 | Rac1 Activity Biosensor in a Stress-Induced Sensitization to Cocaine Model

Cellular and Molecular Neurobiology

Author: Victoria Vaccaro | Email: victoria.vaccaro@unc.edu.ar

Victoria Vaccaro , Julieta Boezio , Daiana Rigoni , Liliana Cancela , Mariano Bisbal , Flavia Bollati

1° Instituto de Farmacología Experimental de Córdoba, IFEC-CONICET, Departamento de Farmacología O. Orsingher, FCQ, UNC-Córdoba, Argentina
2° Instituto de Investigación Médica M. y M. Ferreyra, INIMEC-CONICET, Córdoba, Argentina

Recent studies suggest an important role for RhoGTPase Rac1 signaling in models of cocaine addiction. In our laboratory, we have demonstrated that the modulation of cofilin activity, a regulatory protein involved in actin cytoskeleton dynamics, is crucial to the structural and functional neuroadaptations within the Nucleus Accumbens core (NAc) triggered by chronic stress exposure. These adaptations contribute to an increased vulnerability to cocaine abuse. The activity of cofilin is regulated by Rac1. Our hypothesis proposes that a decrease in Rac1 activity leads to increased cofilin activity in the dendritic spines of the NAc during stress-induced cocaine sensitization.
Thus, the objective of this project is to characterize the activity of Rac1 in the NAc using lentiviral particles that express an activity biosensor based on fluorescence resonance energy transfer (FRET). To design the lentiviral vector, we cloned the Rac1bios2G biosensor from the original pTriEx plasmid into the pLV-eGFP plasmid, incorporating a CMV promoter to optimize its expression. Subsequently, we generated lentiviral particles containing pLV-Rac1bios2G in HEK cell lines.
In our stress-induced cocaine sensitization model, we will administer lentiviral particles into the NAc of male Wistar rats one week after chronic stress exposure (day 14). On day 21, a cocaine challenge injection will be administered, and we will analyze the Rac1 activation pattern at 5, 15, 30, and 45 minutes post-injection.