Distribution of recurrent inhibition in the human upper limb

The distribution of homonymous and heteronymous recurrent inhibition among the motor nuclei innervating the main muscles of the human upper limb has been investigated in 25 healthy subjects. Homonymous recurrent inhibition was studied with a specially designed electrophysiological method with paired H-reflexes, previously described by Bussel & Pierrot-Deseilligny (1977), combined with a pharmacological study using a cholinergic agonist, the L-acetylcarnitine (Rossi & Mazzocchio 1991). These methods were used to investigate the Flexor Carpi Radialis (FCR), Extensor Carpi Radialis (ECR), Opponens Pollicis (OP) and Abductor Digiti Minimi (ADM) motor nuclei