This research project aims to investigate a part of the neural control pathway for reach to grasp movements in cats. These movements are an essential part of many behaviors including feeding and defense. A reach to grasp movement was most likely utilized to pick up this document. When the movement fails, life changes drastically. To repair a deficit, an understanding of the basic neural control of the movement is necessary. The proposed research will contribute to this understanding. One of the fundamental aspects of the neural control of a movement is the organization of its control pathway in the nervous system. What areas of the brain control the movement? How do the control signals change as they progress through the brain? How is the control of the movement organized within the brain structures involved? Dr. Gibson's laboratory has concentrated on the control of the reach to grasp movement. His work has identified a pathway which appears dedicated to the control of the grasping aspect of the reach to grasp movement. This pathway includes the interpositus nucleus in the deep cerebellar nuclei and the magnocellular red nucleus. Neurons in these areas discharge sharply only to reach movements with a grasp. A grasp pathway suggests that there is a reach pathway. Recently, work in Dr. Gibson's laboratory has identified an area of the mesencephalic reticular formation where neurons discharge for reaching during the reach to grasp movement. Preliminary anatomical data from the lab suggests that the dentate nucleus projects to the reach related area of the mesencephalic reticular formation. The proposed research will first investigate the discharge from neurons in the dentate nucleus during reach to grasp movements. Next, the contribution these neural areas make to the reach to grasp will be studied through inactivation experiments of the dentate nucleus and the mesencephalic reticular formation. The deficits from the inactivation of each of the areas will be compared.
