The midbrain contains an important class of neurons that produce the neurotransmitter dopamine. These cells are involved in the production of willful smooth movement of muscles. In people suffering from the neurodegenerative disease Parkinson?s disease, 80 percent or more of these dopamine-producing cells are damaged or lost. The loss of modulation by dopamine results in severe motor deficits. We are working with an accepted model of Parkinsonism in rats. In our model we produce a unilateral lesion of dopaminergic neurons using the neurotoxin 6-OHDA. In addition to causing motor deficits, our model also denervates the hippocampus of dopaminergic inputs. Proper hippocampal function is essential to spatial learning, and memory. This study sought to investigate the effects of hemiparkinsonisms on spatial learning and memory function through the use of a well-established cognitive test called the Morris Water Maze (MWM). The results from our study demonstrate that 6-OHDA lesions can lead to spatial learning and memory deficits.