Abstract
Most adaptive behaviors require precise and continuous tracking of targets in space. We studied the contribution of a striatal microcircuit to target pursuit using a novel continuous pursuit task in freely moving mice. We show that, in the sensorimotor striatum, many parvalbumin-positive fast-spiking interneurons (FSIs) represent the distance between self and target. On the other hand, the striatal projection neurons (SPNs), which receive FSI projections, more commonly represent self-velocity during pursuit behavior. Moreover, FSIs are shown to regulate SPN activity during pursuit, so that movement velocity is continuously modulated by distance to target. Long-term silencing or transient optogenetic manipulation of FSI output can selectively pursuit behavior. Our results reveal a key role of this striatal interneuron circuit in pursuit behavior, suggesting that it is used to convert distance error signals into velocity commands, allowing the animal to use target distance to guide pursuit behavior.