Biomedical subjects

R Matsuzaki

Publications and source records attributed to R Matsuzaki.

28 records · Page 2Linked to original sources

PubMed1993

No-go activity in the frontal association cortex of human subjects.

'No-go potential', specific to the no-go reaction in go/no-go reaction-time hand movement with discrimination between different colour light stimuli, was recorded with electrodes chronically implanted in the prefrontal cortex of monkeys. Similar potentials were widely distributed over frontal-parietal parts of the human scalp on the same no-go reaction. In this report, MEG measurement was made over the scalp of five healthy subjects in order to localize current sources responsible for the scalp potential. We found in- and outflow of magnetic fields over the dorsolateral frontal parts of the head, contra- and ipsilateral to the operant hand. These magnetic fields were most reasonably interpreted to be due to current dipoles localized in the dorsolateral parts of frontal lobes in both contra- and ipsilateral hemispheres, presumably in the prefrontal-premotor areas. No-go decision and subsequent suppression of voluntary movements are suggested to be one of the functional features of the human frontal association cortex, as in the case of monkeys.

Adult↗

PubMed1991

Topographical organization of the tecto-olivo-cerebellar projection in the cat.

The superior colliculus sends a climbing fiber output to cerebellar vermal lobules VI-VII through the inferior olive. The present study in cats morphologically clarified the existence of a topographical organization in the tecto-olivo-cerebellar projection. A horseradish peroxidase study on the tecto-olivary projection showed that the rostral and caudal superior colliculus projected mostly contralaterally to the caudal and rostral areas of the caudomedial part of the medial accessory olive, respectively. The lateral superior colliculus was found to project more laterally than was the medial superior colliculus. Investigation on the olivocerebellar projection demonstrated that the rostral and caudal areas of the caudomedial part of the medial accessory olive sent climbing fiber terminals contralaterally to the lateral and medial parts of vermal lobules VI-VII, respectively. Thus, it was revealed that the rostral superior colliculus projected mostly to the medial part of ipsilateral vermal lobules VI-VII while the caudal superior colliculus projected mostly to the lateral part of ipsilateral vermal lobules VI-VII.

Afferent Pathways↗

PubMed1991

Topographical organization of climbing fiber pathway from the superior colliculus to cerebellar vermal lobules VI-VII in the cat.

Topographical distribution of the climbing fiber responses induced by stimulation of the superior colliculus was investigated in the cerebellar posterior vermis (lobules VI-VII) of the cat. The climbing fiber-responsive areas were distributed longitudinally forming sagittal zones. The sagittal zones responsive to stimulation of the left and right superior colliculus were located on the side ipsilateral to the stimulation, and they were completely segregated. The sagittal zones responsive to stimulation of the caudal superior colliculus were distributed more laterally than those responsive to stimulation of the rostral superior colliculus. Study of the extracellular unit in the inferior olive demonstrated that the climbing fiber responses were relayed in the caudomedial part of the medial accessory olive contralateral to the stimulation.

Animals↗

PubMed1985