Organisation of inputs to spinal interneurone populations

In order to use electrical stimulation or biological repair to attempt to alleviate spinal cord dysfunction, a key problem will be how to target the intervention. Since the majority of inputs to spinal motoneurones originate from intrinsic spinal premotor interneurones, these are key targets for interventions that may help restore function. Information on the organisation of these neurones could thus be crucially important to determine how to proceed. Understanding the organisation of spinal interneurones is no easy task. In this article I review evidence of the connectivity of some of the groups of spinal premotor interneurones that have been studied, focusing particularly on whether they form subgroups and how these can be identified.