Direct Connectivity Between the Inferior Colliculus and Lateral Vestibular Nucleus in the Integration of Auditory and Vestibular Systems

초록

The auditory system receives sound stimuli and transmits information to the brain, allowing us to perceive sounds. When running, accurately recognizing the direction to move in amidst various environmental stimuli requires interactions with other sensory systems, such as vision and proprioception. In particular, the connection between auditory and vestibular sensory systems is essential for daily life, yet research on this relationship remains relatively limited. Previous studies have reported some associations between the inferior colliculus (IC), a key structure integrating ascending auditory signals, and the vestibular nuclei (VN) in the brainstem. For example, an increase in neuronal firing in the IC was observed when the extra auditory canal (EAC) was stimulated with ice water (Song et al., 2020). Additionally, when excitatory neurons in the medial vestibular nuclei (MVN) were stimulated using optogenetics while an auditory stimulus was applied to the contralateral ear, neural activity in the IC increased (Leong et al., 2019). These findings confirmed the connectivity between the VN and IC but did not lead to results related to a direct connection. In this study, we aimed to investigate the direct connection between VN and IC. We also explored whether VN, which is typically associated with balance, responds to other sensory inputs, such as auditory stimuli.