Proprioception from a spinocerebellar perspective

This review explores how proprioceptive sensory information is organized at : spinal cord levels as it relates to a sense of body position and movement . The topic is considered in an historical context and develops a different framework that may be more in tune with current views of sensorimotor proc essing in other central nervous system structures. The dorsal spinocerebell ar tract (DSCT) system is considered in detail as a model system that may b e considered as an end point for the processing of proprioceptive sensory i nformation in the spinal cord. An analysis of this system examines sensory processing,at the lowest levels of synaptic connectivity with central neuro ns in the nervous system. The analysis leads to a framework for propriocept ion that involves a highly flexible network organization based in some way on whole limb kinematics. The functional organization underlying this frame work originates with the biomechanical linkages in the limb that establish functional relationships among the limb segments. Afferent information from limb receptors is processed further through a distributed neural network i n the spinal cord. The result is a global representation of hindlimb parame ters rather than a muscle-by-muscle or joint-by,joint representation.