LEE, MJ*; ANDERSON, CW: Neuroanatomical evidence for integration of olfaction into the frog feeding motor pattern generator

To understand the neural control of movement, it is critical to understand the anatomy of feedback mechanisms that coordinate movement with environmental and postural changes. The specific goal of this project is to identify olfactory projections into the brainstem and to determine if these projections anatomically converge onto previously identified brainstem circuits involved during feeding movements in the leopard frog, Rana pipiens. Using a semi-intact, in vitro preparation, the brain and brainstem was bathed in Sulforhodamine 101 (SR101) while the olfactory nerve was electrically stimulated. Voltage-activated uptake of SR101 revealed labeled Purkinje cells in the cerebellar cortex, reticular formation neurons, the trigeminal nuclei, hypoglossal nuclei and the raphe nuclei. Previous work demonstrates that hypoglossal and glossopharyngeal afferents project to these same areas, suggesting that olfaction directly interacts with the neuronal circuitry of feeding movements.