An ultrastructural morphometric study of developing rat substantia gelatinosa
Article first published online: 26 JAN 2005
Copyright © 1981 Wiley-Liss, Inc.
The Anatomical Record
Volume 200, Issue 2, pages 231–237, June 1981
How to Cite
Kirby, M. L. (1981), An ultrastructural morphometric study of developing rat substantia gelatinosa. Anat. Rec., 200: 231–237. doi: 10.1002/ar.1092000211
- Issue published online: 26 JAN 2005
- Article first published online: 26 JAN 2005
- Manuscript Accepted: 30 DEC 1980
- Manuscript Received: 15 OCT 1980
A morphometric analysis has been done on developing rat substantia gelatinosa of the lower cervical and upper thoracic levels of the spinal cord starting on the 15th day of gestation. The following parameters were measured: cell body diameter, cytoplasmic/nuclear areas, synaptic density, synaptic type and vesicle morphology of the presynaptic terminal in axodendritic synapses. Cell body size and cytoplasmic/nuclear areas of gelatinosal cells increase until the 15th day postnatally and then decrease somewhat to the adult values. The first synapses are seen on gestation day 17. Synaptic density increases linearly until the third day postnatally. Axodendritic synapses are most common throughout development and in the adult, while the proportion of axoaxonic synapses increases and axosomatic synapses decreases during development. Most of the terminals in axodendritic synapses contain clear-spherical vesicles but the occurrence of clear-flat vesicles and dense-cored vesicles in the terminals increases during development. It appears that these morphological parameters provide a stable index of development in the substantia gelatinosa which can be correlated with functional development of the area. Hopefully, they will provide a means to assess subtle anomalies induced by nonteratogenic drugs or other environmental changes.