WORD · Wireless Optogenetics to elucidate the function of corticostriatal neurons in biRDsong

Corticostriatal neurons are vital components of brain circuits that connect cortical areas to the striatum, and are known to play essential roles in the control of cognitive and motor functions. The contribution of these projection neurons in shaping vocal behaviors in the healthy brain and their implications in disease are nonetheless still not well understood. I will use songbirds as a model system to investigate the functional roles of a corticostriatal neuron population during the production of vocal sequences and in reinforcement learning of vocal features. Songbirds are the prime model system to study the neural basis of speech development and complex motor skill acquisition, due to the many parallels between birdsong and human speech and their respective neural correlates. I will investigate corticostriatal neurons in nucleus HVC (proper name), the songbird vocal premotor cortex analog. Neural activity in HVC has been thoroughly studied in the past, but the roles of individual HVC neuron types in mediating vocal sequences and the stereotypy and flexibility of song features remain poorly understood. I will be using optogenetics to manipulate activity in HVC’s corticostriatal neurons during the production of song sequences, and while birds are adapting song features in response to an externally applied aversive auditory stimulus. I will first develop novel tools to enable such investigations in songbirds, including new viral constructs to target specific projection neuron populations and wireless sensor nodes for performing vocal output-triggered optogenetic manipulations without movement restrictions for experimental animals. I will then apply the developed tools to conduct optogenetic manipulations of corticostriatal neurons in freely moving, vocalizing birds in social groups. These experiments will shine new light into the role of corticostriatal neurons in shaping complex vocal behaviors.