Neuronal dropout is greater in hindlimb motor nuclei than in forelimb motor nuclei in aged rats.
The number of forelimb, ulnar (U) and hindlimb, medial gastrocnemius (MG) motoneurons labeled with retrograde axonal transport of horseradish peroxidase was examined in young and aged rats. No significant difference was found between the mean number of U motoneurons in young and aged rats, whereas the mean number of MG motoneurons was significantly lower in aged rats than in young rats. These results suggest that motoneuronal dropout is greater in hindlimb motor nuclei than in forelimb motor nuclei, which may contribute to differential changes in forelimb and hindlimb muscles with increasing age.
Hashizume
K
K
Department of Physiology, Tokyo Metropolitan Institute of Gerontology, Japan.
Kanda
K
K
D000375:Aging / Q000502:physiology*; D000818:Animals; D002452:Cell Count; D005552:Forelimb / Q000254:growth & development / Q000294:innervation*; D006614:Hindlimb / Q000254:growth & development / Q000294:innervation*; D006735:Horseradish Peroxidase; D008297:Male; D009046:Motor Neurons / Q000166:cytology*; D024510:Muscle Development; D009132:Muscles / Q000294:innervation*; D051381:Rats; D011916:Rats, Inbred F344; D013116:Spinal Cord / Q000166:cytology* / Q000254:growth & development
D006735:Horseradish Peroxidase