Sensory-induced activation of pattern generators in the absence of supraspinal control.

Sacrocaudal afferent (SCA) stimulation is used in this work to study neural pathways involved in sensory-activation of central pattern generators (CPGs) in the isolated spinal cord of the neonatal rat. Surgical manipulations of the white matter funiculi and confocal imaging of back-labeled funicular pathways suggest that the CPGs are activated during SCA stimulation by crossed and uncrossed multifunicular projections of sacral neurons and that activation of short projecting proprioneurons is sufficient for the generation of the rhythm by SCA stimulation. The versatile organization of the pathways involved in the SCA-induced rhythm makes it a potent and durable activator of the CPGs in the absence of descending control from the brain. The significance of our findings and their potential clinical use are discussed.