Grant: Discovery Grants Program - Individual

In providing us with a more complete sensory experience, our brains naturally merge information from our different senses (e.g., sight and hearing). In species ranging from mice to humans, there exist functionally-specialized regions of the cortex that are largely populated by neurons capable of processing information from more than one sensory modality (e.g., bimodal neurons). For more than 25 years, a theoretical framework has been championed in the field of multisensory processing which suggests that performance in multisensory behavioral tasks could be derived from the ability of bimodal neurons to show greater response activation to combined-modality stimuli (i.e., multisensory integration). For example, in humans and laboratory animals, it is well established that the reaction time to detect auditory and visual stimuli is fastest when the stimuli are presented together compared to when either stimulus is presented alone. By recording cortical activity in awake-behaving rats, this grant will determine whether this behavioral enhancement is indeed mediated by multisensory integration at the single neuron level. Furthermore, by using a combination of neuropharmacology, electrophysiology and behavioral experiments, the proposed studies will provide the first comprehensive investigation of the effect of local inhibitory neurotransmission on cortical multisensory processing and behavior. Importantly, the graduate students responsible for conducting these integrative studies will acquire advanced experimental skills which are highly marketable in academic and industrial neuroscience research. Ultimately, this grant will improve our understanding of how information processing in multisensory cortical circuits translates into behavioral outcomes. Such knowledge will help with the interpretation of results from an ever-increasing number of functional neuroimaging studies on multisensory processing. Finally, the significance of the proposed studies is not restricted to the field of multisensory processing, as the findings will be relevant to a wide-array of researchers investigating the neuronal basis of sensory processing in general.