Auditory-visual convergence at the superior colliculus in rat using functional MRI

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)5531-5536
Journal / PublicationAnnual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Proceedings
Publication statusPublished - Jul 2018

Conference

Title2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
PlaceUnited States
CityHonolulu
Period18 - 21 July 2018

Abstract

The superior colliculus (SC) of the midbrain has been a model structure for multisensory processing. Many neurons in the intermediate and deep SC layers respond to two or more of auditory, visual, and somatosensory stimuli as assessed by electrophysiology. In contrast, noninvasive and large field of view functional magnetic resonance imaging (fMRI) studies have focused on multisensory processing in the cortex. In this study, we applied blood oxygenation level-dependent (BOLD) fMRI on Sprague-Dawley rats receiving monaural (auditory) and binocular (visual) stimuli to study subcortical multisensory processing. Activation was observed in the left superior olivary complex, lateral lemniscus, and inferior colliculus and both hemispheres of the superior colliculus during auditory stimulation. The SC response was bilateral even though the stimulus was monaural. During visual stimulation, activation was observed in both hemispheres of the SC and lateral geniculate nucleus. In both hemispheres of the SC, the number of voxels in the activation area (p<10 -8) and BOLD signal changes (p<0.01) were significantly greater during visual than auditory stimulation. These results provide functional imaging evidence that the SC is a site of auditory-visual convergence due to its involvement in both auditory and visual processing. The auditory and visual fMRI activations likely reflect the firing of unisensory and multisensory neurons in the SC. The present study lays the groundwork for noninvasive functional imaging studies of multisensory convergence and integration in the SC.

Citation Format(s)

Auditory-visual convergence at the superior colliculus in rat using functional MRI. / Lau, Condon; Manno, Francis A. M.; Dong, Celia M.; Chan, Kevin C.; Wu, Ed X.

In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Proceedings, 07.2018, p. 5531-5536.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review