Purpose. Under this Funding Opportunity Announcement (FOA), the National Institute of Neurological Disorders and Stroke (NINDS), the National Institute on Aging (NIA), and the National Institute of Mental Health (NIMH) invite research grant applications to develop new, or improve existing, animal models which address the underlying neurobiological mechanisms associated with cognitive impairment and mood disturbance in Parkinson's disease (PD), that assist in the development of clinical interventions and therapeutics for cognitive impairment and affective symptoms in PD, or that promote improved treatment of cognitive and affective impairment in PD. A goal of this FOA is to begin a process where basic and clinical scientists from various disciplines can overcome barriers to cross-disciplinary and biobehavioral research and examine all aspects of cognition and affective regulation in the context of the diagnosis and treatment of Parkinson's disease. Mechanism of Support. This FOA will use the NIH Exploratory/Developmental (R21) grant mechanism and runs in parallel with a FOA of identical scientific scope, PA-09-033, that encourages applications under the R01 mechanism. Funds Available and Anticipated Number of Awards. Because the nature and scope of the proposed research will vary from application to application, it is anticipated that the size and duration of each award will also vary. The total amount awarded and the number of awards will depend upon the mechanism, numbers, quality, duration, and costs of the applications received.