A defective control of small-amplitude movements in monkeys with globus pallidus lesions: an experimental study on one component of pallidal bradykinesia

• Published in: Behavioural brain research Vol. 72; no. 1; pp. 57 - 62
• Main Authors: Alamy, Meryem, Pons, Jean-Claude, Gambarelli, Danielle, Trouche, Elisabeth
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 14-12-1995; Elsevier Science
• Subjects: Accuracy constraint; Animals; Biological and medical sciences; Choice Behavior - physiology; Excitatory Amino Acid Agonists - toxicity; Fundamental and applied biological sciences. Psychology; Globus pallidus; Globus Pallidus - anatomy & histology; Globus Pallidus - physiology; Injections; Monkey; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Movement - physiology; Movement amplitude; Movement Disorders - physiopathology; Movement time; Papio; Proprioception - physiology; Quisqualic Acid - toxicity; Quisqualic acid lesion; Reaction Time - physiology; Reaction time task; Vertebrates: nervous system and sense organs; Accuracy constraint; Monkey; Globus pallidus; Movement time; Movement amplitude; Reaction time task; Quisqualic acid lesion; Amplitude; Motor system disorder; Central nervous system; Basal ganglion; Motor control; Pallidum; Visuomotor tracking; Vertebrata; Mammalia; Choice reaction time; Body movement; Primates; Lesion; Motricity; Brain (vertebrata)
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/0166-4328(96)00048-4

The effects of globus pallidus (GP) lesion were examined in two monkeys trained to perform a visually guided pointing movement in simple and choice reaction time tasks involving small and large amplitude movements. The reaction time (RT) and the movement time (MT) were measured. The Y-axis error (EY) was also analyzed in order to assess the movement accuracy. Unilateral GP lesion was made by locally injecting an excitatory amino acid, quisqualic acid. GP lesion led to little change in the RTs (simple and choice RTs) and in the EY, whereas a large increase in the MT occurred. The MT impairments seem to have been correlated with the movement amplitude, since they were larger in the case of small-amplitude than large-amplitude movements. These results suggest that the GP may be involved in the control of small-amplitude rather than large-amplitude movements. As various studies have shown that proprioceptive cues are more strongly involved in the control of discrete than large-amplitude movements, the MT deficit, i.e., the bradykinesia observed here, may reflect a defective integration of proprioceptive information occurring after GP lesion.