Sound-evoked responses of distinct neuron classes from the tail of the striatum

Abstract

Given its inputs from auditory structures and neuromodulatory systems, the posterior tail of the striatum is ideally positioned to influence behavioral responses to acoustic stimuli according to context and previous rewards. Results from previous studies indicate that neurons in this striatal region display selective responses to sounds. However, it is not clear whether different striatal cell classes code for distinct features of sounds, nor how different striatal output pathways may use acoustic information to guide behavior. Here we compared the sound-evoked responses of posterior striatal neurons that form the striatal direct pathway (and express the dopamine receptor D1) to the responses of neighboring neurons in naive mice. We achieved this via optogenetic photo-identification of D1-expressing neurons during extracellular electrophysiological recordings in awake head-fixed mice of both sexes. We found that the frequency tuning of sound-responsive direct-pathway striatal neurons is comparable to that of their sound-responsive neighbors. Moreover, we found that both populations encode amplitude modulated sounds in a similar fashion. These results suggest that different classes of neurons in the posterior striatum of naive animals have similar access to acoustic features conveyed by the auditory system even outside the context of an auditory task.

Significance Statement

Sound-driven decision-making is a key component of an animal’s behavioral repertoire in their quest for positive outcomes. Subsets of neurons in the striatum (a brain area associated with motor control and the integration of reward information) receive inputs from the auditory system, yet what features of sounds are accessible to specific striatal cell classes is not well understood. We found that multiple classes of posterior striatal neurons have access to detailed spectro-temporal acoustic features and could therefore potentially influence behavioral responses according to these properties of sounds.