Characterization of neuronal activity of the striatum during a habit-inducing learning task

MARTÍNEZ, MARÍA CECILIA; ZOLD, CAMILA; BELFORTE, JUAN; MURER, MARIO GUSTAVO; BELLUSCIO, MARIANO

Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2013

Habits involve a structured action sequence that can be elicited by a particular context or stimulus. They are acquired by experience-dependent plasticity and once fixed, they are performed almost automatically. It is currently thought that synaptic plasticity in the striatum, the entrance gateway for cortical inputs to the basal ganglia, mediates habit formation. Theory says that signals produced by mesencephalic dopaminergic neurons and striatal cholinergic interneurons in response to reward related cues induce such plasticity and are essential for habit formation. With the aim of characterizing striatal activity during the acquisition of a rewarded conditioning task, we recorded the local field potential and unit activity in the striatum of freely moving rats during task learning. Trials were initiated by a light signal delivered after a nose-poke. Water-deprived rats were rewarded with a drop of water in 50% of the trials after completion of eight licks, and could initiate a new trial after a two second interval. We are analyzing neuronal activity in relationship with different events of the task, like reward delivery and reward expectancy, and events occurring outside the task like impulsive nose-pokes during the ITI. Also, we study behavioral parameters of the task related to learning at different stages of training. We plan to study task learning and neuronal activity in adolescent and adult rats under the hypothesis that behavioral control is immature in adolescents.