Schiller PH; Tehovnik EJ
European Journal of Neuroscience,
2003, 18(11): 3127-33.
Abstract
The role inhibitory circuits play in target selection with saccadic eye movements
was examined in area V1, the frontal eye fields (FEF) and the lateral intraparietal
sulcus (LIP) of the Rhesus Macaque monkey by making local infusions of the GABA
agonist muscimol and antagonist bicuculline. In V1, both agents greatly interfered
with target selection and visual discrimination of stimuli placed into the receptive
field of the affected neurons. In the FEF, bicuculline facilitated target selection
without affecting visual discrimination and generated many spontaneous saccades.
Muscimol in the FEF interfered with saccadic eye-movement generation. In the
LIP, bicuculline was ineffective and muscimol had only a small effect. These
findings suggest that in the FEF GABAergic inhibitory circuits play a central
role in eye-movement generation whereas in V1 these circuits are essential for
visual analysis. Inhibitory circuits in the LIP do not appear to play a central
role in target selection and in visual discrimination.