Synaptic noise-triggered averaging as a technique for investigating the origin of EPSPs

A method to investigate the origin of EPSPs has been introduced and its application to recordings from spinal motoneurons allows an estimate to be made of the proportion of spontaneous EPSPs being of monosynaptic muscle afferent origin. Furthermore its application to the largest muscle stretch evoked EPSPs indicates that they can be of either monosynaptic muscle spindle Ia action or can be interneuronally mediated.