Grant: Operating Grant

The majority of neurons (up to 85%) in the brain are found in the cerebellum. The cerebellum integrates information from various sensory systems and is involved in numerous processes including motor control, learning and cognition. How the cerebellum organizes information from the various senses is still poorly understood. The cerebellum has a unique organization: some neurochemicals are expressed as "stripes" throughout the cerebellum. The most thoroughly studied of these neurochemicals is the enzyme aldolase C, also known as zebrin. Although the exact role of zebrin is not clear, it is expressed in the same way in all vertebrate species studied, indicating that it is essential for cerebellar function. The organization is such that there are stripes of neurons that express zebrin alternating with stripes of cells that do not express zebrin. The goal of the proposed research is to understand how these stripes relate to function and processing of information in the cerebellum. We use a part of the cerebellum known as the vestibulocerebellum as a model. This is an area where visual, vestibular and spinal information is integrated in order to control eye movements, posture and locomotion, and balance. To understand how information is organized with respect to the zebrin stripes, we will determine how the visual, vestibular, and spinal connections are associated with particular zebrin stripes in the vestibulocerebellum. Moreover, we will record from neurons in particular zebrin stripes to determine the nature of sensory processing within each stripe. These studies will provide basic information about the principles of fundamental sensory organization in the cerebellum. This is critical for understanding diseases of the vestibulocerebellum that cause disturbances of visuo-motor behaviour (e.g., oscillopsia, oculomotor abnormalities, vertigo), and diseases that affect the cerebellum in general such as Wernicke's encephalopathy, Alzheimer's disease and autism.