A DEFECTIVE CONTROL OF SMALL-AMPLITUDE MOVEMENTS IN MONKEYS WITH GLOBUS-PALLIDUS LESIONS - AN EXPERIMENTAL-STUDY ON ONE-COMPONENT OF PALLIDAL BRADYKINESIA

Citation
M. Alamy et al., A DEFECTIVE CONTROL OF SMALL-AMPLITUDE MOVEMENTS IN MONKEYS WITH GLOBUS-PALLIDUS LESIONS - AN EXPERIMENTAL-STUDY ON ONE-COMPONENT OF PALLIDAL BRADYKINESIA, Behavioural brain research, 72(1-2), 1995, pp. 57-62
Citations number
33
Categorie Soggetti
Neurosciences,Neurosciences
Journal title
ISSN journal
01664328
Volume
72
Issue
1-2
Year of publication
1995
Pages
57 - 62
Database
ISI
SICI code
0166-4328(1995)72:1-2<57:ADCOSM>2.0.ZU;2-I
Abstract
The effects of globus pallidus (GP) lesion were examined in two monkey s trained to perform a visually guided pointing movement in simple and choice reaction time tasks involving small and large amplitude moveme nts. The reaction time (RT) and the movement time (MT) were measured. The Y-axis error (EY) was also analyzed in order to assess the movemen t accuracy. Unilateral GP lesion was made by locally injecting an exci tatory amino acid, quisqualic acid. GP lesion led to little change in the RTs (simple and choice RTs) and in the EY, whereas a large increas e in the MT occurred. The MT impairments seem to have been correlated with the movement amplitude, since they were larger in the case of sma ll-amplitude than large-amplitude movements. These results suggest tha t the GP may be involved in the control of small-amplitude rather than large-amplitude movements. As various studies have shown that proprio ceptive cues are more strongly involved in the control of discrete tha n large-amplitude movements, the MT deficit, i.e., the bradykinesia ob served here, may reflect a defective integration of proprioceptive inf ormation occurring after GP lesion.