Auditory-visual Information Integration And Plasticity In Rat Cortex

Unified perception of stimuli that was seen, felt and heard requires that regions of the brain receive convergent inputs from these different sensory modalities and that these convergent inputs are integrated. Bounding the different modality sensory is of important value in enhancing the detecting, localization and identification of external events or objects. Multisensory integration has been well studied in the superior colliculus (SC) of cat. There are fertile bimodal or trimodal neurons in the deep layer of SC. However, what is less known is Multisensory integration in the cerebral cortex. The rodent cortex offers advantages as a model for such an exploration because its sensory representations are well known and its lissencephalic (i.e., lacking in convolutions) nature makes marking the functional transitions across sensory areas comparatively straightforward. In current study ,we defined the distribution of auditory-visual neurons in rat cortex ,at the same time .analyzed the integration characteristics of bimodal neurons. Based on that we examined the experience-dependent plasticity of bimodal neurons. The study consisted of two parts.Firstly, conventional electrophysiological technique was used to determine the distribution of auditory-visual multisensory neurons and to study the auditory-visual information integration in rat cortex. We isolated 217 auditory-visual bimodal neurons including 108 A-V neurons which can not only response to auditory stimuli but also to visual stimuli, 48 v-A neurons only responsing to auditory stimuli, but can be altered when visual stimuli were presented at the same or almost the same time, and 61 a-A neurons only responsing to visual stimuli, but can be altered when auditory stimuli were presented at the same or almost the same time. These bimodal neurons mainly located in the boundary areas between auditory and visual cortex were...