Losing Control: Excessive Alcohol Seeking after Selective Inactivation of Cue-Responsive Neurons in the Infralimbic Cortex.

Hebb's (1949) idea of memories as being represented in local neuronal networks is supported by identification of transiently stable activity patterns within subgroups of neurons. However, it is difficult to link individual networks to specific memory tasks, for example a learned behavior. By a novel approach of activity-dependent ablation, here we identify a specific neuronal ensemble located in the infralimbic subregion of the medial prefrontal cortex that controls a seeking response for alcohol in rats. Our data demonstrate that functional output depends on specific neuronal ensembles within a given brain region rather than on the global activity of that region, which raises important questions about the interpretation of numerous earlier experiments using site-directed silencing or stimulation for elucidating brain function.