To survive in an ever-changing world, animals need to rapidly detect and appropriately respond to external stimuli. In the auditory system, the inferior colliculus (IC) is well-positioned as an obligatory auditory hub involved with making acousticomotor responses to initiate these behavioral responses to auditory stimuli. However, it is not well understood how the relevant contextual information needed to detect and respond appropriately to stimuli is conveyed. In this thesis, I investigate the cerebellar vermis as one possible source of this contextual information.
My experiments revealed that optogenetic stimulation of the cerebellar vermis robustly modulates the majority of neurons throughout IC in awake mice head-fixed on a treadmill. Because I was to monitor the movement of the treadmill, I also found that vermis stimulation produces a similar behavioral response as auditory stimuli, and that vermis evoked activity in the IC is in part related to this motor response. Furthermore, my results show that animal running modulates IC activity by reducing auditory and vermis responses, while increasing spontaneous activity
