Circuits for multisensory processing

In everyday life, our brain combines information from different senses to create a representation of the environment to select appropriate behaviour through a process known as multisensory integration. Multisensory integration is one of the core functions of the cerebral cortex where it has a great impact on cognitive functions. The perirhinal cortex is an associative area receiving inputs from all sensory systems and is involved in sensory processing and memory. The perirhinal circuits involved in multisensory integration are still unknown as well as the sensory and multisensory responses of perirhinal neurons. This gap of knowledge hampers our understanding of how the brain creates representations of the objects in our environment. We will use a combination of in vivo and in vitro neurophysiological measurements to unveil the circuits involved in generating neuronal responses to sensory inputs. Neuroanatomical measurements will identify the neural pathways involved in multisensory integration. The experiments proposed require surgery under anaesthesia for implantation of head-posts and intracranial injections, hence the severity level is moderate. A mild water restriction lasting for a few hours will motivate the mice to lick a spout and achieve a reward. We calculated the maximum number of animals to be used in 1900 mice (wild type and transgenic) of either sex. We aim to reduce the number of animals used by implementing optimal training in surgical and experimental procedures to all researchers involved. By implementing state-of-the-art Neuropixel probes, we will be able to record several neurons from each animal, leading to a reduction in the number of animals. Mice are housed in group in enriched environments to improve their wellbeing and their recovery from surgery. Mice are given 7 days to acclimate to a new environment upon arrival to the facility. Experiments will be performed on mice that have been habituated to handling and to the experimental set up to reduce levels of discomfort and improve the quality of the data obtained. Although sensory physiology requires experiments on living animals, our data will be publicly available as soon as possible to allow computational neuroscientists to develop accurate models of cortical function. This will lead to well defined hypothesis for future research leading to a reduced number of experimental animals needed or in some case to replacement of animals with computational models. These experiments will provide fundamental information to advance our understanding of cortical functions such as perception and memory. This information will greatly advance our knowledge on fundamental processes that are affected in neurological disorders such as autism, schizophrenia and Alzheimer’s disease.