RESUMO
The striatal cholinergic system is key in detecting changes in instrumental contingencies. While recent evidence supports this vision, cell type-specific online control on the activity of the cholinergic striatal neurons is necessary to empirically test it. In this study, we performed optogenetic manipulations of the activity of striatal cholinergic interneurons (CINs) to evaluate their contribution to the updating of a previously learned instrumental contingency. By modulating the activity of CINs, we identified that the inhibition of CINs impairs the update of actions to a contingency change. Remarkably, a manipulation that perturbs the activity of CINs, rather than inhibiting them also impaired the encoding of the change in contingency. These results emphasize that beyond an increase in the activity of CINs, the intact activity of these cells is required for the identification of an instrumental contingency change.