Neurons and microvessels of the nodose (vagal sensory) ganglion in young adult and aged rats: morphometric and enzyme histochemical studies.
The neuron cell bodies and microvessels in sections of the nodose (vagal sensory) ganglion (NG) of Wistar rats of 4- and 24-months of age have been examined morphometrically and by quantitative enzyme histochemistry. The range of neuronal somata areas was similar at the two ages and distributed unimodally, ranging approximately from 200-1500 microns 2 with the largest somata occurring in the older age group. The range of microvessel diameters was also comparable but the largest microvessels were seen in the older animals. The histological arrangement of the ganglion permitted analyses to be made of 'neuronal' and 'axonal' areas independently. The number of microvessels per unit area was less in regions of the ganglion occupied by axons at both ages. Random transects indicated that the percentage area occupied by neuron somata decreases and that of axons increases with age. Overall, however, the results suggest that the histological organization, the size of vagal sensory neurons, the ganglionic microvessels, and the relationship between them, does not change greatly in Wistar rats of up to 2 years of age. Ultrastructural features of the aged sensory neurons included the presence of secondary lysosomes, disrupted rough endoplasmic reticulum, swollen Golgi cisternae, and the presence of much filamentous material in the perikaryon similar to that seen in chromatolytic neurons. However, analysis of electron micrographs did not reveal significant changes in the numbers of mitochondria or Golgi bodies. There was an overall increased thickness in the microvascular wall in the older animals with the endothelium and pericyte covering being significantly increased, but the thickness of the basal lamina was unchanged. The activities of neuronal NADH tetrazolium reductase, succinate dehydrogenase and cytochrome oxidase were all increased with age. The results suggest that vagal sensory neurons are not greatly affected by age in the rat.
Soltanpour
N
N
School of Molecular and Medical Biosciences (Anatomy Unit), University of Wales College of Cardiff, UK.
Baker
D M
DM
Santer
R M
RM
D000375:Aging / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D006651:Histocytochemistry / Q000379:methods*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D009474:Neurons / Q000201:enzymology / Q000648:ultrastructure*; D009620:Nodose Ganglion / Q000098:blood supply / Q000166:cytology* / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar