Parkinson’s Disease (PD) is a neurodegenerative disease associated with a loss of dopaminergic neurons in the basal ganglia, located in the midbrain. PD patients are typically over the age of 50 because dopamine production slows due to continuous degeneration of dopamine cells as age progresses. Individuals with the disease typically exhibit both motor and non-motor symptoms, including some autonomic issues. Motor symptoms occur early in the disease, and are described as tremors, muscle rigidity and slowness of movement. A common autonomic issue is bladder dysfunction, typically caused by detrusor overactivity, leading to nocturia, increased urgency and increased frequency.
This project aims to recreate these urinary symptoms in laboratory rats by injecting 6-OHDA into the periaqueductal grey area of the midbrain and the lumbosacral spinal cord. The purpose of the injection is to prove that the loss of dopaminergic neurons are in fact the cause of these bladder issues. The current protocol begins with a 6-OHDA injection in the intended area (either into the midbrain or the CSF in the lumbosacral spinal cord) and requires the periodic monitoring of micturition patterns in awake rats with the use of diuresis chambers. After this period of observation, the animals are anesthetized for a terminal procedure that examines and records bladder-sphincter reflexes. Lastly, immunohistochemistry is used to test for tyrosine hydroxylase (TH), a dopamine marker, once the brain and spinal cord are removed. It is anticipated that these manipulations will result in changes in LUT function similar to those that occur in PD.