Despite the fundamental significance of temporal order on brain function, little is known about the circuit mechanisms that underlie the ability to generate and learn sequences. In the songbird premotor pathway, information concerning the production of learned vocalizations is encoded in the spatiotemporal activity patterns within a higher-order nucleus, named HVC. In the present proposal, in vivo intracellular recordings will be used to better understand the mechanisms involved in generating precisely timed sequences of activity within HVC. These experiments will address the role of synaptic inhibition and afferent inputs in generating stereotyped neuronal codes. Furthermore, the ontogeny of sequential activity within HVC will be considered in order to address the means by which learned vocalizations are encoded. The present proposal has direct relevance for human speech learning in that songbirds, unlike most animals such as nonhuman primates, are capable of learning vocalizations.
