摘要:

CHARACTERISTICS of muscular contraction induced by magnetic stimulation were studied using isolated gastrocnemius muscles of a frog. The figure-eight coil position was regarded as 0° when the direction of induced current was parallel to the muscle fiber axis, and 90° when the induced current was perpendicular to the muscle fiber axis. Muscular contraction readily occurred with lower outputs of magnetic stimulation at 0° and 180°, but it was weak at 90° and 270°. Magnetic stimulation did not directly induce muscular contraction but it acted on the synapses forming end plates to muscle cells, and muscular contraction occurred if the direction of the eddy current was parallel to the nerve which innervated the muscle cells.

ISSN:0959-4965    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

SYNAPTIC function is critical for cell-cell communication and the characterization of proteins that function during vesicle formation, transport and fusion events will yield further insight into the mechanisms of synaptic transmission. We have cloned and characterized a gene product expressed in human brain called hCDCrel-1. This protein is a new member of the septin family of gene products that functions during cytokinesis in lower eukaryotes. In this study we characterize the expression of the hCDCrel-1 gene and localize the hCDCrel-1 protein to neurons in adult human brain. hCDCrel-1 co-purifies with SNAP-25 and synaptophysin marked synaptosomes, suggesting a novel function for this gene family in the brain. Our data indicate that members of the septin family of proteins may function in synaptic vesicle transport, fusion or recycling events in the human brain.

ISSN:0959-4965    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

THE planum temporale (PT), a portion of Wernicke's area, is important for linguistic functions in humans and is larger in the left compared to the right hemisphere. In this study, we assessed the presence and size of the PT in a sample of non-human primates including 21 great apes, four lesser apes, 11 Old World monkeys and eight New World monkeys using magnetic resonance imaging. The PT was measured in both the sagittal and coronal planes by use of multiplanar reformatting software. The PT could only be identified in the sample of great apes and not in the remaining non-human primate species. Within the great ape sample, the PT was larger in the left hemisphere than in the right in a statistical majority of the subjects. These results are consistent with the notion that the PT evolved as a definable structure about 15 million years ago and may have arisen as a result for selection for greater cortical folding which in turn led to greater gyrification in larger brains.

ISSN:0959-4965    

出版商:OVID    

年代:1998

数据来源: OVID