Skilled motor control for the preclinical assessment of functional deficits and recovery following nigral and striatal cell transplantation.

Neural transplantation holds the promise for restoring behavioral function following brain injury. Substantial evidence indicates that fetal neurons transplanted to the adult brain survive and incorporate into remaining neural tissue and produce positive behavioral effects. A yet-unanswered question is whether the integration of new tissue can restore complex neural circuits that connect the neocortex, basal ganglia, and brainstem, and restore functions that are mediated by these circuits. This chapter describes the skilled reaching task, a task that requires transport of the arm and hand to grasp a food item and withdrawal to place the food item in the mouth for eating. It is a movement that is readily expressed in rodents and is fundamental to both nonhuman primates and humans. Methods for analyzing skilled reaching have been developed for preclinical rodent and mouse models of Parkinson's disease and Huntington's disease that are generalizable to humans with those clinical disorders. It is suggested that the task provides a motor benchmark for assessing the restoration of function produced by neural transplantation.