Pulvinar inactivation disrupts selection of movement plans.
The coordinated movement of the eyes and hands under visual guidance is an essential part of goal-directed behavior. Several cortical areas known to be involved in this process exchange projections with the dorsal aspect of the thalamic pulvinar nucleus, suggesting that this structure may play a central role in visuomotor behavior. Here, we used reversible inactivation to investigate the role of the dorsal pulvinar in the selection and execution of visually guided manual and saccadic eye movements in macaque monkeys. We found that unilateral pulvinar inactivation resulted in a spatial neglect syndrome accompanied by visuomotor deficits including optic ataxia during visually guided limb movements. Monkeys were severely disrupted in their visually guided behavior regarding space contralateral to the side of the injection in several domains, including the following: (1) target selection in both manual and oculomotor tasks, (2) limb usage in a manual retrieval task, and (3) spontaneous visual exploration. In addition, saccades into the ipsilesional field had abnormally short latencies and tended to overshoot their mark. None of the deficits could be explained by a visual field defect or primary motor deficit. These findings highlight the importance of the dorsal aspect of the pulvinar nucleus as a critical hub for spatial attention and selection of visually guided actions.
Wilke
Melanie
M
Unit on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health-National Institutes of Health, Bethesda, Maryland 20892, USA. melanie.wilke@vis.caltech.edu
Turchi
Janita
J
Smith
Katy
K
Mishkin
Mortimer
M
Leopold
David A
DA
D000818:Animals; D001522:Behavior, Animal; D001931:Brain Mapping; D003657:Decision Making / Q000187:drug effects / Q000502:physiology; D004594:Electrophysiology; D005133:Eye Movements / Q000187:drug effects / Q000502:physiology*; D005260:Female; D018755:GABA Agonists / Q000494:pharmacology; D007555:Isoxazoles / Q000494:pharmacology; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D009118:Muscimol / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D020649:Pulvinar / Q000187:drug effects / Q000502:physiology*; D014794:Visual Fields
D018755:GABA Agonists; D007555:Isoxazoles; D009118:Muscimol; C015542:gaboxadol