Control of digits via C3-C4 propriospinal neurones in cats; recovery afterlesions

C3-C4 propriospinal neurones (C3-C4 PNs) transmit the command for forelimb target-reaching in cats, while the command for food-taking is mediated by i nterneurones in the forelimb segments. The ability of the C3-C4 PNs to cont rol digits has now been reinvestigated with combined lesions in dorsal C5 ( transecting the cortico- and rubrospinal tracts) and Ventral C2 (transectin g reticulospinal tracts) leaving the C3-C4 PNs in sole control of the forel imb. Components of food-taking like flexion in the proximal interphalangeal joints were found in half of the cats. Supination and terminal flexion of the metacarpophalangeal joints by which normal cats bring the morsel of foo d to the mouth were lacking in all cats. (C) 2000 Elsevier Science Ireland Ltd and the Japan Neuroscience Society. All rights reserved.