Faculty Collaboration Database

Naturally occurring motoneuron cell death in rat upper respiratory tract motor nuclei: a histological, fast DiI and immunocytochemical study in the hypoglossal nucleus. J Neurobiol 1995 Aug;27(4):520-34

Date

08/01/1995

Pubmed ID

7561831

DOI

10.1002/neu.480270407

Scopus ID

2-s2.0-0029133329 (requires institutional sign-in at Scopus site)   27 Citations

Abstract

We have previously reported on our investigation of motoneuron cell death (MCD) in the rat nucleus ambiguus (NA). This article focuses on the other major upper respiratory tract motor nucleus: the hypoglossal. The hypoglossal nucleus (XII) contains motoneurons to the tongue and, as such, plays a critical role in defining patterns of respiration, deglutition, and vocalization. Motoneuron counts were made in XII in a developmental series of rats. In addition, the neural tracer fast DiI was used to ensure that all hypoglossal motoneurons had migrated into the nucleus at the time cell death was assessed. Furthermore, an antibody to gamma-aminobutyric acid (GABA) was used to determine the potential effect of inadvertently counting large interneurons on motoneuron counts. Cell death in XII was shown to occur entirely prenatally with a loss of 35% of cells between embryonic day 16 (E16) and birth. Fast DiI tracings of the prenatal hypoglossal nerve indicated that all motoneurons were present in a well-defined nucleus by E15. Immunocytochemical staining for GABA demonstrated considerably fewer interneurons than motoneurons in XII. These findings in XII, in comparison with those previously reported for NA, demonstrate differences in the timing and amount of cell death between upper respiratory tract motor nuclei. These differences establish periods during which one nucleus may be preferentially insulted by environmental or teratogenic factors. Preferential insults may underlie some of the upper respiratory tract incoordination pathologies seen in the newborn such as the sudden infant death syndrome (SIDS).

Author List

Friedland DR, Eden AR, Laitman JT

Author

David R. Friedland MD Associate Director, Director, Chief, Professor in the Otolaryngology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Apoptosis
Carbocyanines
Fluorescent Dyes
Hypoglossal Nerve
Immunohistochemistry
Interneurons
Motor Neurons
Rats
Rats, Sprague-Dawley
Respiratory System
gamma-Aminobutyric Acid