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Hikosaka, O.

Publications and source records attributed to Hikosaka, O..

2 recordsLinked to original sources

Amygdala controls saccade and gaze physically, motivationally, and socially

The amygdala is uniquely sensitive to emotional events. However, it is not understood whether and how the amygdala uses such emotional signals to control behavior, especially eye movements. We therefore injected muscimol (GABAA agonist) into the central nucleus of amygdala (CeA) in monkeys. This unilateral temporary inactivation suppressed saccades to contralateral but not ipsilateral targets, resulting in longer latencies, hypometric amplitudes, and slower velocity. During free viewing of movies, gaze was distributed mostly in the ipsilateral hemifield. Moreover, CeA inactivation disrupted the tendency of gaze toward social interaction images, which were normally focused on continuously. Conversely, optogenetic stimulation of CeA facilitated saccades to the contralateral side. These findings suggest that CeA controls spatially selective gaze and attention in emotional contexts, and provide a new framework for understanding psychiatric disorders related to amygdala dysfunction.\n\nHighlightsO_LICentral amygdala facilitates contralateral saccades selectively.\nC_LIO_LISaccade facilitation is related to motivational goals and social interaction.\nC_LIO_LIThe amygdala thus controls goal-directed behavior based on emotional contexts.\nC_LI

neuroscience

Indirect pathway of caudate tail for choosing good objects in periphery

Choosing good objects is essential for real life, which is controlled mainly by the basal ganglia. For that, a subject need to not only find good objects, but reject bad objects. To reveal this rejection mechanism, we created a sequential saccade choice task for monkeys and studied the indirect pathway of caudate tail mediated by cvGPe (caudal-ventral globus pallidus externus). The inhibitory responses of cvGPe neurons to bad objects were smaller when the monkey made saccades to them by mistake. Moreover, experimental reduction of the inhibitory response by local injection of bicuculline (GABAA antagonist) disabled the monkey to reject bad objects. In conclusion, rejecting bad objects is crucial for goal-directed behavior, which is controlled by the indirect pathway in the basal ganglia.

neuroscience