The optogenetic technique allows study of the causal role of millisecond-scale activity of genetically or anatomically defined populations of neurons. In this paper, Smith and Graybiel use optogenetics to study habitual behavior, specifically the neural basis of habit formation. With optogenetic methods, they show that a small site in the medial prefrontal cortex can control habits on-line during their execution, and were able to control new habits when they compete with prior ones. The nearly immediate effect of disabling this site optogenetically suggests the existence of a mechanism for moment-to-moment monitoring of behaviors that had long been thought to be almost automatic and reflexive in nature. This study highlights the kind of new knowledge that can be gained by the carefully timed use of optogenetic techniques. This article is part of a Special Issue entitled Optogenetics (7th BRES).
Smith KS, Graybiel AM: Using optogenetics to study habits. Brain Research [Epub ahead of print Jan. 10, 2013; doi: 10.1016/j.brainres.2013.01.008].