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Entwicklung und Zelldifferenzierung des Nucleus nervi hypoglossi beim Rind
Author(s) -
Ruhrig S.,
Kötter B.,
Hummel G.,
Goller H.
Publication year - 1995
Publication title -
anatomia, histologia, embryologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.34
H-Index - 35
eISSN - 1439-0264
pISSN - 0340-2096
DOI - 10.1111/j.1439-0264.1995.tb00009.x
Subject(s) - nucleus , anatomy , ultrastructure , hypoglossal nucleus , spinal cord , electron microscope , biology , physics , optics , neuroscience
Summary Based upon light‐ and electron‐microscope examinations, the ontogenetic development of the nucleus of cranial nerve XII is documented. At 1‐cm crown‐rump length (CRL), the caudal pole of the nucleus nervi hypoglossi forms a uniform cell column with the cornu ventrale of the spinal cord. During this period, its caudal area shows signs of cellular degeneration. From 3.5 cm CRL onward, all nuclear groups can be identified. At 53 cm CRL, they correspond to the pattern as described in the adult brain. Electron‐optically, at 2.5 cm and 3.6 cm CRL, the nucleus of cranial nerve XII exhibits a close relationship to the matrix layer which consists of elements of dark nuclei. The hypoglossus nucleus is composed of dark and light cell types. It is the latter type that represents the presumptive neuron; it shows an increased ultrastructural differentiation from 2.5 cm CRL onward.