Motor cortical activity during voluntary gait modifications in the cat. I. Cells related to the forelimbs.

摘要: 1. The discharge patterns of 91 identified pyramidal tract neurons (PTNs), located within the forelimb region area 4 cat motor cortex, were recorded during voluntary modifications gait needed to step over obstacles attached a moving treadmill belt. Recordings made simultaneously from flexor and extensor muscles acting around shoulder, elbow, wrist, digits contralateral recording site. 2. Analysis changes in electromyographic (EMG) activity modification showed increases most shoulder as well wrist digit dorsiflexors, when was first pass obstacle. This period augmented could be subdivided into two parts: one associated with initial flexion limb that bring it above obstacle (phase I), second increased dorsiflexor muscle before foot contact II). 3. frequency total 57/91 (63%) PTNs significantly site obstacle; six these also significant decrease their different part cycle. In further 21/91 (23%) neurons, only decreased, whereas remaining 13/91 (14%) similar both control walking modifications. 4. Most those (47/57) which firing observed, discharged maximally physiological muscles. Twenty-three cells (23/47) phase I, 12 (12/47) II. A third population PTNS started increase stance cycle immediately preceding modified Seven (7/57) cycle, three not classified being preferentially related any 5. modulation 41/57 less leg encounter many there an appreciable change time peak occurred. These amplitude timing paralleled observed temporal relationships muscles.(ABSTRACT TRUNCATED AT 400 WORDS)