Bladder function is controlled by spinal reflexes involving spinal motoneurons, which connect to muscles in the periphery, and interneurons, which make their connections within the central nervous system. The activity of these spinal neurons is coordinated by higher centers in the brain. The object of the present work by Drs. Collins and Erichsen is to identify and characterize these spinal motoneurons, both anatomically and physiologically. At present, little is known about these neurons, particularly the spinal interneurons; this lack of knowledge is the result of the inability to identfy function-specific spinal interneurons and to establish their connections within the spinal cord. Recently, the investigators of these studies have developed both the electrophysiological and neuroanatomical techniques which will enable them to achieve this objective. The use of a multidisciplinary approach in this research will allow a more comprehensive examination and analysis of individual spinal neurons than would be possible with any single technique. The information obtained from these experiments will provide an essential database of the locations, functional identities, and synaptic connections of spinal interneurons involved in the control of bladder function.