Dynamics of depolarization and hyperpolarization in the frontal cortex and saccade goal.
The frontal eye field and neighboring area 8Ar of the primate cortex are involved in programming and execution of saccades. Electrical microstimulation in these regions elicits short-latency contralateral saccades. To determine how spatiotemporal dynamics of microstimulation-evoked activity are converted into saccade plans, we used a combination of real-time optical imaging and microstimulation in behaving monkeys. Short stimulation trains evoked a rapid and widespread wave of depolarization followed by unexpected large and prolonged hyperpolarization. During this hyperpolarization saccades are almost exclusively ipsilateral, suggesting an important role for hyperpolarization in determining saccade goal.
Seidemann
Eyal
E
Department of Neurobiology and the Grodetsky Center for Studies of Higher Brain Function, Weizmann Institute of Science, Rehovot 76100, Israel. eyal.seidemann@weizmann.ac.il
Arieli
Amos
A
Grinvald
Amiram
A
Slovin
Hamutal
H
D000818:Animals; D001931:Brain Mapping; D004558:Electric Stimulation; D004594:Electrophysiology; D005453:Fluorescence; D005625:Frontal Lobe / Q000502:physiology*; D000882:Haplorhini; D008564:Membrane Potentials; D009474:Neurons / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D013997:Time Factors