The microenvironment of the spinal ganglion neuron in the rat during aging

The environment and particularly the glial sheath of the spinal ganglion neurons was systematically studied by light and electron microscopy in the young and senescent rat. Experiments using radioactive tracers tested the consequences of the functional perturbations associated with structural impairments. The results suggested the possibility that the glial sheath and the neuron aged differently. Whereas the glial sheath maintained its functional capacity relatively intact, neuronal performance was markedly and more rapidly impeded. The morphology and volume of the extracellular space were unchanged. Therefore, impairment of the glioneuronal units in the spinal ganglion during aging cannot be assigned to environmental and vascular phenomena.