Much evidence suggests that the basal ganglia and cortico-basal ganglia loops are centrally involved in learning how to perform sequences of acts so smoothly that we can carry them out almost without conscious effort. This type of learning is crucial for maximizing cognitive function. But what is the type of neural processing that lets us transform behaviors into habits? And how do we break them once they are formed? The goal of research in our laboratory is to answer these questions. We use two experimental approaches to focus on these issues. First, we record chronically with multiple electrodes from ensembles of neurons in the striatum and cortex of monkeys, rats and mice as they undergo training in learning tasks. For example, the lab has found large-scale and long-lasting changes in the response properties of striatal neurons as T-maze learning takes place in rats, and finds that these changes occur at the population level. Neuronal firing patterns in the frontal cortex and striatum of macaque monkeys also undergo pattern changes as the monkeys learn motor tasks and then perform them "automatically" as routines, and as the monkeys shift cognitive strategies during learning. These findings suggest that during habit learning, there are dynamic changes in ensemble activity that occur in cortico-striatal networks. The second approach of the lab is to seek molecular events that correlate with such behavioral changes. The lab maps early-response genes for initial clues to identify relevant circuits, has cloned novel striatum-enriched genes to allow transgenic approaches to studying habit learning, and now is engineering mice with deletions of these genes.
Affiliate Member, Picower
Center for Learning and Memory Walter A. Rosenblith Professor of Neuroscience
Department of Brain and Cognitive Sciences
Investigator, McGovern Institute for Brain Research