start-ver=1.4 cd-journal=joma no-vol=68 cd-vols= no-issue=7 article-no= start-page=911 end-page=933 dt-received= dt-revised= dt-accepted= dt-pub-year=1956 dt-pub=19560731 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Physiological and histological study on the different extension of the motor cortex of the brain Part Ⅱ. On the motor cortex of the monkey brain kn-title=生理学的並に組織解剖学的にみたる大脳皮質運動領の範囲の差異に関する研究 第2編 猿脳皮質運動領における研究 en-subtitle= kn-subtitle= en-abstract= kn-abstract=The same method of investigation as stated in part Ⅰ was used on 4 cases of the monkey brain (Macaca muletta). 1) The extent of the center for the hind limb responded to electric stimulation was almost as same as or a little narrower than the extent with the Betz cells, while the extent of the center for the fore limb was much wider than the extent with the Betz cells. 2) The extent with motor response first appeared like islands at the threshold voltage, became larger as the voltage increased and then the extents for the upper and lower limbs became doubled, thus making the mixed area. 3) This enlargement of the mixed area by increased stimulation had a tendency to move towards the center for the lower limb. 4) The threshold of stimulation was the lowest at the center for the upper limb, then at that for the lower limb, and the highest at the mixed area. And even in the same center, the threshold was lower at the central part with more Betz cells and higher at the peripheral part with less Betz cells. From these facts, it would appear that the extent of the motor cortex determined physiologically is not always the same as the extent of the distribution of the Betz cells, but is due to the density and sensitivity of the original nerve cells of the pyramidal tract, regardless of the size of the cells. en-copyright= kn-copyright= en-aut-name=MichinakaTomokatsu en-aut-sei=Michinaka en-aut-mei=Tomokatsu kn-aut-name=道中智勝 kn-aut-sei=道中 kn-aut-mei=智勝 aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=岡山大学医学部第一(陣内)外科教室 END start-ver=1.4 cd-journal=joma no-vol=68 cd-vols= no-issue=7 article-no= start-page=901 end-page=910 dt-received= dt-revised= dt-accepted= dt-pub-year=1956 dt-pub=19560731 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Physiological and histological study on the different extension of the motor cortex of the brain Part Ⅰ. On the motor cortex of the human brain kn-title=生理学的並に組織解剖学的にみたる大脳皮質運動領の範囲の差異に関する研究 第1編 人脳皮質運動領における研究 en-subtitle= kn-subtitle= en-abstract= kn-abstract=Electric stimulation was performed on the motor cortex of the human brain in 30 cases of epileptics and then histological investigation was made on the removed specimen of the brain. The extent of the center for the upper limb was relatively wide and the extent of the center for the lower limb was hardly discovered by electric stimulation. In the center of the upper limb, the extent for fingers was the widest and responded by the lowest voltage, then following order of the wrist, the elbow and the shoulder joint. The area anteriorly close to the Rolandic fissure, even if without any motor response to electric stimulation, had mostly the giant pyramidal cells of Betz, especially the area close to the midline had always bigger Betz cells. The gyri anteriorly distant from the Rolandic fissure, even if with motor response to electric stimulation, hardly had the Betz cells. No Betz cells were observed in the responded area of the area 6 and posterior to the Rolandic fissure. From these results the theory seems to be not reliable that the motr response caused by electric stimulation is due to the Betz cells. en-copyright= kn-copyright= en-aut-name=MichinakaTomokatsu en-aut-sei=Michinaka en-aut-mei=Tomokatsu kn-aut-name=道中智勝 kn-aut-sei=道中 kn-aut-mei=智勝 aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=岡山大学医学部第一(陣内)外科教室 END