Spinal cord injury leads to atrophy in pelvic ganglia neurons

Among the most devastating sequelae of spinal cord injury (SCI) are genitourinary and gastrointestinal dysfunctions. Post-ganglionic neurons in pelvic ganglia (PG) directly innervate and regulate the function of the lower urinary tract (LUT), bowel, and sexual organs. A better understanding of how SCI affects PG neurons is essential to develop therapeutic strategies for devastating gastrointestinal and genitourinary complications ensuing after injury. To evaluate the impact of SCI on the morphology of PG neurons, we used a well- characterized rat model of upper thoracic SCI (T3 transection) that causes severe autonomic dysfunction. Using immunohistochemistry for neuronal markers, the neuronal profile size frequency distribution was quantified at one-, four-, and eight-weeks post SCI using recursive translation. Our investigation revealed an SCI-dependent leftward shift in neuronal size (i.e. atrophy), observable as early as one-week post injury. However, this effect was more pronounced at four and eight-weeks post-SCI. These findings demonstrate the first characterization of SCI-associated temporal changes in morphology of PG neurons and warrant further investigation to facilitate development of therapeutic strategies for recovery of autonomic functions following SCI.