Postnatal development of hypoglossal motoneurons that innervate the hyoglossus and styloglossus muscles in rat.
Postnatal development of hyoglossus and styloglossus motoneurons was studied in this investigation of the hypoglossal nucleus. Our findings show separate and distinct locations for hyoglossus and styloglossus motoneurons within the retrusor (dorsal) subdivision of the hypoglossal nucleus for all age groups. Hyoglossus and styloglossus motoneuron cross-sectional area reached their adult size at different times (by weeks 2 and 3, respectively). Cell roundness, as measured by form factor (measure of cell perimeter relative to its area), decreased with advancing postnatal age for both populations of motoneurons. Differences in the direction of the dendritic projection between hyoglossus and styloglossus motoneurons were found. Hyoglossus and styloglossus motoneuron development was compared to genioglossus motoneuron postnatal development.
Smith
J Chadwick
JC
Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia 23298, USA. jcsmith@vcu.edu
McClung
J Ross
JR
Goldberg
Stephen J
SJ
D000818:Animals; D000831:Animals, Newborn; D002772:Cholera Toxin / Q000737:chemistry / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D007002:Hypoglossal Nerve / Q000166:cytology* / Q000254:growth & development* / Q000378:metabolism; D007202:Indicators and Reagents / Q000737:chemistry / Q000378:metabolism; D009046:Motor Neurons / Q000166:cytology* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000294:innervation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014059:Tongue / Q000294:innervation*
D007202:Indicators and Reagents; D002772:Cholera Toxin; D006735:Horseradish Peroxidase