title: Cross-correlation reveals facilitation of single motor units in thenar muscles by single corticospinal neurones in the conscious monkey.
abstract: The functional connections between corticospinal neurones and motor units of the monkey's hand muscles were investigated by constructing cross-correlograms of activity recorded from pyramidal tract neurones and from single motor units in the contralateral thenar muscles during performance of a precision grip between thumb and index finger. Only those neurones which produced postspike facilitation of the surface-recorded electromyogram (EMG) of these muscles were selected for analysis. Positive correlations were observed for 11/15 selected neurones, and the form of the correlation was suggestive of monosynaptic action. Corticospinal cells which produced a correlation peak often did so with all concurrently-sampled motor units.
mesh_terms: D000818:Animals; D004576:Electromyography; D004594:Electrophysiology; D006225:Hand; D008254:Macaca nemestrina; D009132:Muscles / Q000294:innervation*; D009474:Neurons / Q000502:physiology*