Structural changes in the nucleus of the solitary tract following chorda tympani nerve cut in young rats

Taste buds convey sensory information to the brain via the chorda tympani nerve (CT). The CT transmits taste information from the anterior two-thirds of the tongue to the nucleus of the solitary tract (NTS). The NTS is the central first relay station where sensory information about taste is communicated to neurons in the brain. Previous research conducted to investigate the effects of chorda tympani transections (CTX) revealed plasticity of the sensory system for taste, the gustatory system. CTX surgeries are useful as they enable examination of CT functionality. For example, we can examine whether CT removal impacts cell structure in the NTS. The present experiment focused on identification of how CTX affects development in the brainstem. Twenty female Sprague-Dawley rats were utilized to explore plasticity of neurons within the rostral portion of the NTS. For this study, rats underwent bilateral CTX or a control surgery at 10 days of age. When the rats were adults (minimum of 50 days after surgery), the brains were extracted and placed in a Golgi stain to allow visualization of somas and dendrites. After the tissue was stained, it was frozen and then sectioned on a cryostat at 200μm, followed by neuronal tracing using the program Neurolucida (MicroBrightField, Inc.). Neurolucida enables precise tracking of structural changes that may take place s a result of CTX. Currently, work is being done to investigate possible modifications in neural pathways conveying sensory information to the brain and other effects resulting from diminishing sensory input from the CT