Pallidal Neuron Activity During Sequential Arm Movements . Mushiake, Hajime and Peter L. Strick. Research Service (151), V.A. Medical Center, Departments of Neurosurgery and Physiology, SUNY Health Science Center at Syracuse.
APStracts 2:0295N, 1995.
SUMMARY AND CONCLUSIONS
1. We examined the activity of neurons in the globus pallidus (GP) while monkeys (n=2) performed sequential pointing movements under two task conditions: visually guided (TRACK task) and remembered (REM task). 2. Almost two-thirds of the task-related neurons in GP (155/236) were considered task- dependent because they displayed exclusive or enhanced (>+/-50%) changes in activity for 1 of the 2 task conditions. 3. More than 65% of the task- dependent neurons were termed REM neurons because they either displayed changes in activity that occurred only during the REM task or displayed changes that were more pronounced (>+/-50%) during the REM task than during the TRACK task. 4. Nearly half of the REM neurons in GP displayed changes in activity that were limited to a single phase of the REM task (i.e., phase- specific). Phase-specific neurons varied in the extent to which their activity depended on the particular sequence of movements performed. Some displayed a change in activity for all of the eight different movement sequences. Others displayed a change in activity during only one of the eight different sequences (i.e., phase- and sequence-specific). 5. We speculate that an ensemble of GP neurons with phase-specific responses could be used to encode the detailed spatio-temporal characteristics of a sequential movement. In this way, GP neurons would provide part of the neural substrate that solves the "serial order of motor behavior problem". 

Received 10 August 1995; accepted in final form 25 September 1995.
APS Manuscript Number J525-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95