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The present study provides evidence that the saccadic signals in the caudate nucleus (caudate) are transmitted to the substantia nigra pars reticulata (SNr). We inserted two microelectrodes into the caudate and SNr of monkeys trained to perform saccade tasks. After identifying the functional characteristics of a SNr neuron recorded, we stimulated the(More)
The synaptic organization of the saccade-related neuronal circuit between the superior colliculus (SC) and the brainstem saccade generator was examined in an awake monkey using a saccadic, midflight electrical-stimulation method. When microstimulation (50-100 microA, single pulse) was applied to the SC during a saccade, a small, conjugate contraversive eye(More)
The basal ganglia contribute to the suppression and initiation of saccadic eye movements through the inhibitory connection from the substantia nigra pars reticulata (SNr) to the superior colliculus. This mechanism consists of serial and parallel connections, which are mostly inhibitory and GABAergic. Dopamine is known to exert powerful modulatory effects on(More)
Unilateral dopamine deficiency of the basal ganglia produced a profound impairment of visual search. Dopaminergic innervation of the monkey striatum was deprived unilaterally by infusing 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into the caudate nucleus. The monkeys were shown a mirror in which they saw their own image and surroundings. Compared(More)
Unilateral infusion of MPTP into the monkey caudate nucleus produced deficits in task-specific saccades, in addition to the deficits in spontaneous eye movements (preceding article). We trained three monkeys to perform two kinds of saccade tasks: (1) saccade task for eliciting visually guided saccades and (2) delayed saccade task for eliciting memory-guided(More)
Microrecordings were performed during pallidotomy and thalamotomy for Parkinson's disease (PD). Neuronal activity in globus pallidus (GP) was in general agreement with previous studies of human and primate models of PD. Neuronal activity, where frequency of tremor appeared to oscillate independently from peripheral input, was encountered in GPi. In(More)
We report a patient with anosognosia for hemiplegia associated with a right pontine infarction. A 51-year-old woman with histories of hypertension and diabetes mellitus was admitted because of weakness of her left upper and lower extremities. On neurologic examination, she was alert and oriented without dementia. Visuospatial hemineglect was not present.(More)
Stereotaxic pallidotomy for Parkinson's disease (PD) is an old concept, which was gradually and mostly replaced by thalamotomy. Recently, posteroventral pallidotomy (PVP), originally proposed by Leksell et al., was reintroduced; this paper examines PVP in terms of its historical background, technical aspect and location of the surgical lesion, as well as(More)
We recorded saccade-related neurons in the vicinity of the dentate nucleus of the cerebellum in two monkeys trained to perform visually guided saccades and memory-guided saccades. Among 76 saccade-related neurons, 38 showed presaccadic bursts in all directions. More than 80% of such burst neurons were located in the area ventral to, not inside, the dentate(More)
We report a 49-year-old man who was an HTLV-I carrier with an immunodeficiency state and intracranial pyramidal tract lesion revealed by MRI. He was born in Hokkaido and was admitted to our hospital because of fluminant hepatitis. On admission, neurologic examination revealed exaggerated deep tendon reflexes including the jaw jerk; the plantar response was(More)