PINK1 knockout rats show premotor cognitive deficits measured through a complex maze

Cognitive decline in Parkinson's disease (PD) emerges up to 10 years before clinical recognition. Neurobiological mechanisms underlying premotor cognitive impairment in PD can potentially be examined in the PINK1 ^-/- rat, which exhibits a protracted motor onset. To enhance translation to human PD cognitive assessments, we tested a modified multiple T-maze, which measures cognitive flexibility similarly to the Trail-Making Test in humans. Like human PD outcomes, PINK1 ^-/- rats made more errors and took longer to complete the maze than wild types. Thus, we have identified a potential tool for assessing cross-species translation of cognitive functioning in an established PD animal model.