Studies on regeneration in the spinal cord. IV. Rotation about its longitudinal axis of a portion of the cord in Amblystoma punctatum embryos

✍ Scribed by Hooker, Davenport

• Publisher: John Wiley and Sons
• Year: 1930
• Tongue: English
• Weight: 835 KB
• Volume: 55
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1400550104

✦ Synopsis

There is abundant evidence that the amphibian cord when severed is capable of reestablishing anatomical and functional continuity. Regeneration occurs whether the cord be merely severed or a portion, either homoplastic or heteroplastic in origin, be introduced either in normal or reversed polarity. Various studies have appeared on the regenerative capacity of the embryonic amphibian spinal cord after surgical interference. The operations include section,' reversal of the polarity of a portion: and lateral rotation of a piece about a vertical pivot at an angle of from 90" to 135" to the sagittal plane of the embryo.s Wieman (1.c.) has shown that pieces of the cord implanted with normal dorsoventral orientation, but perpendicular to the longitudinal axis of the cord, may become fused with the normal cord, though they fail to become incorporated in it as a functional unit of the whole. Such grafts fail to block the reestablishment of functional conducting paths between the ends of the original cord. When, however, the graft is laterally rotated to an angle of 135" from its original position, but with normal dorsoventral relations, it may be incorporated in the resulting complete