Differential effects of cocaine and methylphenidate on GABA release from thalamic reticular nucleus [Poster Number 198 / Session I]

B. GOITIA; M. RAINERI; E. GARCIA-RILL; V. BISAGNO; F. J. URBANO

Huerta Grande, Cordoba

Congreso; XXVII Congreso SAN 2012; 2012

Sociedad Argentina de Investigacion en Neurociencias (SAN)

Methylphenidate (MPH), a drug used to treat children diagnosed with attention deficit/hyperactivity disorder, shares mechanistic similarities to cocaine (COC), but its effects on GABAergic transmission in sensory thalamic nuclei are unknown. We compared COC and MPH effects on GABAergic projections between thalamic reticular and ventrobasal (VB) nuclei. We subjected mice (P18-30) to binge-like Coc and MPH acute and sub-chronic administrations, and evaluated locomotion and patch-clamp GABA-A-mediated currents from VB neurons in thalamocortical slices. Sub-chronic COC-mediated effects on hyperlocomotion were stronger than MPH effects. Sub-chronic COC and MPH altered paired-pulse and spontaneous GABAergic input differently. The effects of COC on evoked paired-pulse GABA-A mediated currents changed from depression to facilitation with the duration of the protocols used, while MPH induced a constant increase throughout administration protocols. Our results suggest that COC and MPH produced distinct presynaptic alterations on GABAergic transmission. Differential effects of COC on postsynaptic VB calcium currents might explain deleterious COC effects on sensory thalamic nuclei. These results also help to understand the impact of MPH repetitive administration on sensory thalamic nuclei. FONCYT-PICT 2007-1009, PICT 2008-2019 & PIDRI-PRH 2007 (Dr. Urbano), CONICET- PIP 2011-2013-11420100100072 (Dr. Bisagno), and by NIH grants P20 GM103425-09, and R01 NS020246-25 (Dr. Garcia-Rill).