Ikuko Takeyama

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In this study, 20 subjects (5 women and 15 men, 22-28 years old) were tested for vertical optokinetic nystagmus (OKN) to establish the asymmetry between up and down OKN responses in humans. The subjects were exposed to both upward and downward OKN stimulus at constant velocities of 30, 40, 50, 60, 70, 80, 90 degrees/s in the upright position. Eye movements(More)
The role of the neuronal activity of nucleus prepositus hypoglossi (NPH) in optokinetic stimulation (OKS) and the changes of the activity between OKS and off-OKS (resting condition) were investigated in 5 adult cats. In order to make OKS velocity equal to retinal slip velocity, the cats' eyes were immobilized. The directions of the OKS were clockwise (CW)(More)
The nucleus of the optic tract (NOT) in the pretectum is the visuo-motor relay between the retina and preoculomotor structure in the pathway conveying signals responsible for optokinetic nystagmus (OKN) in both afoveate and foveate animals. Unilateral lesions of the NOT abolish OKN toward the side ipsilateral to the lesion. However, what parts of the retina(More)
There are several reports of clinical trials of aspirin in sporadic colon cancer. However, only one double-blind trial of aspirin in patients with familial adenomatous polyposis (FAP) has been reported to date. This double-blind, randomized, placebo-controlled clinical trial was therefore performed to evaluate the influence of low-dose aspirin(More)
A 24-year-old man was admitted to the University Hospital showing severe dehydration that might have been the result of medicine-induced gastritis. Wernicke's encephalopathy was suspected in this patient. On admission, primary position upbeat nystagmus (PPUN) was found. The patient showed tongue fasciculation and loss of gag reflex, which, however, soon(More)
To determine the lesions and the lateralization in patients with Wallenberg's syndrome, visually-guided eye movements were quantitatively analysed and these findings were compared with a lesioned site as revealed by magnetic resonance imaging (MRI). The 8 patients could be clearly classified into two subgroups based on the functional test of eye movements.(More)
In the present study, gamma aminobutyric acid (GABA)-positive cells and terminals were detected in the nucleus of the optic tract (NOT) in the rat. However, GABA-positive cells in the NOT receiving projections directly from retinal ganglion cells could not be identified. To determine the role of GABA in the projection from the retinal ganglion cells to the(More)
The anatomical features of the dorsolateral pontine nucleus (DLPN) implicate a role of the nucleus in the generation of smooth-pursuit eye movements. The DLPN receives convergent inputs from a variety of parieto-occipital cortical visual areas and projects its fibers to the flocculus and vermal lobules VI and VII. In addition to cortical afferent fibers,(More)
Vestibulo-thalamic (VT) neurons were physiologically studied in the anesthetized cat. Forty-seven VT neurons were recorded extracellularly. More than half of the VT neurons responded monosynaptically to vestibular nerve stimulation while the others responded polysynaptically. They were activated antidromically from one or two sites in the VPL. VPM, VL, VM,(More)
EOG tests were performed in patients with lesions in either the superior or the middle cerebellar peduncle, because these patients showed cerebellar signs and symptoms and were difficult to distinguish from patients with cerebellar lesions symptomatically. EOGs of these patients showed a predominant decrease of pursuit gains and OKN velocity gains toward(More)