Abstract
The neurohypophysis of the opossum (Didelphis virginiana) was studied by electron microscopy in order to amplify Bodian's classic light microscopic observations in which he demonstrated a definite lobular pattern. The lobule of the opossum neurohypophysis is divided into three regions: a hilar, a palisade, and a septal zone. The hilar portion contains bundles of nerve fibers, the extensions of the hypothalamo-hypophyseal tract containing neurofilaments but few neurosecretory granules. In the opossum, pituicytes have a densely fibrillar cytoplasm. Herring bodies are prominent in the hilar region. They are large bodies packed with neurosecretory granules that have been described as end bulb formations of axons. From the hilar region, axons fan out into a palisade zone where the nerve terminals packed with neurosecretory granules, mitochondria, and microvesicles abut upon basement membranes. The neurosecretory granules are similar to those present in the neurohypophysis of other mammals, except for an occasional huge granule of distinctive type. Material morphologically and histochemically resembling glycogen occurs as scattered particles and as aggregates within nerve fibers. The septal zone, containing collagen, fibroblasts, and numerous small capillaries, is separated from the adjacent glandular tissue by a basement membrane.
Full Text
The Full Text of this article is available as a PDF (2.0 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BARGMANN W. Weitere Untersuchungen am neurosekretorischen Zwischenhirn-Hypophysensystem. Z Zellforsch Mikrosk Anat. 1955;42(3):247–272. [PubMed] [Google Scholar]
- FUJITA H., HARTMANN J. F. Electron microscopy of neurohypophysis in normal, adrenaline-treated and pilocarpinetreated rabbits. Z Zellforsch Mikrosk Anat. 1961;54:734–763. doi: 10.1007/BF00339634. [DOI] [PubMed] [Google Scholar]
- GREEN J. D. The comparative anatomy of the hypophysis, with special reference to its blood supply and innervation. Am J Anat. 1951 Mar;88(2):225–311. doi: 10.1002/aja.1000880204. [DOI] [PubMed] [Google Scholar]
- HARTMANN J. F. Electron microscopy of the neurohypophysis in normal and histamine-treated rats. Z Zellforsch Mikrosk Anat. 1958;48(3):291–308. doi: 10.1007/BF00384336. [DOI] [PubMed] [Google Scholar]
- PALAY S. L. The fine structure of secretory neurons in the preoptic nucleus of the goldish (Carassius auratus). Anat Rec. 1960 Dec;138:417–443. doi: 10.1002/ar.1091380404. [DOI] [PubMed] [Google Scholar]
- SCHARRER E., BROWN S. Neurosecretion. XII. The formation of neurosecretory granules in the earthworm, Lumbricus terrestris L. Z Zellforsch Mikrosk Anat. 1961;54:530–540. doi: 10.1007/BF00340453. [DOI] [PubMed] [Google Scholar]
- Shanklin W. M. Histogenesis of pituicytes in the chick. J Anat. 1944 Apr;78(Pt 3):79–93. [PMC free article] [PubMed] [Google Scholar]
- Shanklin W. M. On the presence of nerve cells in the neurohypophysis of the dog. J Anat. 1943 Apr;77(Pt 3):241–242. [PMC free article] [PubMed] [Google Scholar]