Presumptive relationships between ventricular proliferation and development of the lateral motor columns in the spinal cord of Rana pipiens larvae
Article first published online: 3 FEB 2005
Copyright © 1976 Wiley-Liss, Inc.
American Journal of Anatomy
Volume 147, Issue 2, pages 183–192, October 1976
How to Cite
Pollack, E. D. (1976), Presumptive relationships between ventricular proliferation and development of the lateral motor columns in the spinal cord of Rana pipiens larvae. Am. J. Anat., 147: 183–192. doi: 10.1002/aja.1001470203
- Issue published online: 3 FEB 2005
- Article first published online: 3 FEB 2005
- Manuscript Accepted: 28 APR 1976
- Manuscript Received: 30 MAR 1976
The extent of mitotic activity in the proliferative ventricular zone of the developing frog (Rana pipiens) spinal cord is a function of both the longitudinal cord level and the developmental stage. Counts of mitotic cells in the ventricular zone demonstrated higher levels of proliferation in the dorsal than ventral halves of the spinal cord with decreasing total proliferative activity from the early to late larval (tadpole) stages. Mitoses were virtually absent from the ventricular zone by the conclusion of metamorphosis.
Changes in mitotic counts at different levels of the spinal cord can be correlated with the presence or absence of the brachial or lumbosacral pairs of lateral motor columns. A parallel also exists between the caudo-cephalic direction of motor column development and a similar progression of mitotic activity in the ventricular zone, a portion of which gives rise to the spinal motor neurons.
It is suggested that proliferation in the ventricular zone during the larval frog stages contributes to the presumptive motor neuron population that migrates into the lateral motor columns during their later maturation.