Higher Nervous Control of Quadrupedal vs Bipedal Locomotion in Non-human Primates; Common and Specific Properties

Abstract

Bipedal (Bp) terrestrial locomotion is a routine, everyday activity for humans and advanced non-human primates. While its elaboration seems simple, it actually involves much skill and long-term locomotor learning, such that the CNS can achieve a seamless spatial and temporal integration of multiple motor segments. To advance understanding of the GNS control mechanisms that operate during Bp locomotion, it seemed necessary to make use of a non-human primate model. This strategy invites the possibility of employing state-of-the-art interventional recording techniques and cellular-to-systems level of neuroscientific analysis to the study of locomotion. We think that the study of posture and locomotion is fundamental to the understanding of basic brain-behavior relationships from the cellular to the behavioral level of analysis. To this end, we used operant conditioning to train the normally quadrupedal (Qp)-walking juvenile Japanese monkey (M. fuscata) to stand upright and walk bipedally on the surface of a moving treadmill belt. Our M. fuscata studies have started to reveal brain mechanisms involved in the successful emergence and elaboration of Bp locomotion.