Related Experiment Videos
[Development and cell differentiation in the nucleus nervi hypoglossi in cows]
1Institut für Veterinär-Anatomie, -Histologie und -Embryologie, Justus-Liebig-Universität Giessen, Deutschland.
Anatomia, Histologia, Embryologia
|March 1, 1995
Summary
This study documents the ontogenetic development of the hypoglossal nucleus (cranial nerve XII) in humans. Key nuclear groups are identifiable by 3.5 cm crown-rump length (CRL), with presumptive neurons showing differentiation from 2.5 cm CRL.
Area of Science:
- Neuroscience
- Developmental Biology
- Embryology
Context:
- The development of cranial nerve nuclei is crucial for understanding brain formation.
- The hypoglossal nucleus (cranial nerve XII) controls tongue movement and its development is essential for swallowing and speech.
- Previous research has described the adult structure, but detailed ontogenetic stages are less understood.
Purpose:
- To document the ontogenetic development of the nucleus of cranial nerve XII using light and electron microscopy.
- To identify key developmental milestones, including cellular differentiation and nuclear group formation.
- To correlate developmental stages with crown-rump length (CRL).
Summary:
- Light and electron microscopy revealed the ontogenetic development of the nucleus of cranial nerve XII.
- At 1 cm CRL, the caudal pole of the nucleus nervi hypoglossi is a uniform cell column with spinal cord ventral horn, showing degeneration.
- By 3.5 cm CRL, all nuclear groups are identifiable, and by 53 cm CRL, the structure matches the adult pattern. Presumptive neurons within the hypoglossus nucleus show ultrastructural differentiation from 2.5 cm CRL onward.
Impact:
- Provides a detailed timeline of hypoglossal nucleus development in human embryos.
- Offers insights into the cellular and ultrastructural changes during early neuronal differentiation.
- Establishes a foundation for further research into congenital abnormalities affecting cranial nerve XII.