Neural activity in primate caudate nucleus associated with pro- and antisaccades.
The basal ganglia (BG) play a central role in movement and it has been demonstrated that the discharge rate of neurons in these structures are modulated by the behavioral context of a given task. Here we used the antisaccade task, in which a saccade toward a flashed visual stimulus must be inhibited in favor of a saccade to the opposite location, to investigate the role of the caudate nucleus, a major input structure of the BG, in flexible behavior. In this study, we recorded extracellular neuronal activity while monkeys performed pro- and antisaccade trials. We identified two populations of neurons: those that preferred contralateral saccades (CSNs) and those that preferred ipsilateral saccades (ISNs). CSNs increased their firing rates for prosaccades, but not for antisaccades, and ISNs increased their firing rates for antisaccades, but not for prosaccades. We propose a model in which CSNs project to the direct BG pathway, facilitating saccades, and ISNs project to the indirect pathway, suppressing saccades. This model suggests one possible mechanism by which these neuronal populations could be modulating activity in the superior colliculus.
Ford
Kristen A
KA
Graduate Program in Neuroscience, University of Western Ontario, London, Ontario N6A 5K8, Canada.
Everling
Stefan
S
D000200:Action Potentials; D000704:Analysis of Variance; D000818:Animals; D002421:Caudate Nucleus / Q000502:physiology*; D003463:Cues; D007839:Functional Laterality; D008253:Macaca mulatta; D008297:Male; D008839:Microelectrodes; D008959:Models, Neurological; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D012438:Saccades / Q000502:physiology*