Key Central Pattern Generators of the Spinal Cord

In the central nervous system (CNS), central pattern generators (CPGs) are generally considered as specialized networks that can produce oscillatory motor output in the absence of any oscillatory input. For instance, respiration and mastication are among the critical biological functions well known to be controlled by such specialized networks. Several other CPGs have also been found specifically in the spinal cord. Among them, the CPG for locomotion is probably the most extensively studied rhythm- and pattern-generating network of the CNS. Other, less completely understood CPGs have also been associated with the control of scratching, micturition, and ejaculation. This review provides a brief update on CPG organization and function in the spinal cord and focuses on similarities and differences between these networks and their pharmacological modulation. (C) 2009 Wiley-Liss, Inc.