Effect of repetitive cocaine “binge” administration on GAD65/67 and T-type subunits levels from GABAergic somatosensory thalamic neurons in mic

B. GOITIA; M. RAINERI; L. GONZALEZ; J. L. ROZAS; O. D. UCHITEL; E. GARCIA-RILL; V. BISAGNO; F. URBANO

Congreso; XXVI Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2011

Sociedad Argentina de Investigación en Neurociencia

A cocaine "binge" induces an enhancement in both GABAergic transmission and T-type calcium currents on Ventrobasal (VB) thalamic neurons, which were prevented by the systemic administration of T-type calcium channel antagonists mibefradil and 2-octanol. However, it is unknown if protein levels of GAD65/67 or T-type calcium channel subunits are affected by cocaine. The objective of this study was to assess, using Western Blotting, the effects of acute and chronic cocaine "binge" on GAD65/67, Cav3.1 and Cav3.3 T-type subunits protein levels compared to saline administration from mice thalamic VB and Reticular (RetN) nuclei. One day after a chronic "binge" protocol (one "binge" a day, for 3 days) an increase in protein levels of Cav 3.1 was observed in the VB nucleus (ANOVA p=0.01), while no changes in GAD65/67 levels were found. After a fourth "binge" administration, no changes were observed in VB Cav 3.1 protein levels. GAD67 levels were increased in RetN nucleus (ANOVA p=0.024). No differences were found in GAD65/67 protein levels in the VB nucleus. Changes in the expression levels of these two key proteins may help understand alterations in thalamocortical networks of long-term cocaine abusers. Grants: PICT 2007-1009/2008-2019, PIDRI-PRH 2007, PIP 11420100100072.