Early Cognitive Impairment in Hemi-Parkinson’s Disease Rat Model: A TH+ Immunoreactivity and MRI Correlation Study

The neuropathological changes in Parkinson’s Disease (PD) consists in progressive degeneration of nigrostriatal dopaminergic axons (DA), leading to clinical signs when DA cell loss both in the substantia nigrapars compacta (SNc) and in striatum are severely reduced [1-2]. It was reported that both caudate and putamen DA content were significantly related to executive functioning suggesting that the distinction between cognitive and higher order motor organization may be only artificial [2]. This study correlates the effect of a selective destruction of DA and terminals within the striatum and the execution of a set-shifting task as revealed using tyrosine hydroxylase (TH+) immunoreactivity and MRI in the rat.