The effects of x-irradiation on the spinal cords of neonatal rats. II. Histological observations

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Journal of Neuropathology and Experimental Neurology

DOI:https://doi.org/10.1097/00005072-196304000-00008· OSTI ID:4645472

GILMORE, SHIRLEY ANN

Histopathologic studies of the spinal cord were conducted on the rats irradiated with a single dose of 4430 r soft x rays. Inhibition of myelin formation was observed within the spinal cord in all irradiated areas, with apparently normal amounts of myelin above and below the lesion. No extensive change in myelin of the spinal roots was noted. There was a marked decrease in the number of neuroglial nuclei at the site of irradiation as early as 2 days postirradiation. Hypertrophy of astrocyte nuclei was present by 9 to 11 days postirradiation. There were no widespread alterations in ventral horn cells, which seemed to develop to the adult form as seen by their shape of the cell and accumulation of Nissl substance. Petechial hemorrhages were observed in both gray and white matter, most frequently in rats examined 9 to 11 days postirradiation, occasionally in those at 6 days, but never in those at 2 and 4 days after irradiation. Endothelial swelling was also noted at 9 to 11 days postirradiation. It was difficult to correlate these histopathological changes with the flaccid paralysis observed in the animals 9 to 11 days after irradiation: although all animals exhibited the histopathological changes, all were not paralyzed. Furthermore, the histopathological changes occurred very soon after irradiation, whereas paralyss was not evident until later (9 to 11 days postirradiation). The seemingly selective, destructive, early action of ionizing radiation on neuroglia observed here has not been previously described. This loss of both mature and immature forms of neuroglia was evident as early as 2 days postirradiation, the earliest period studied. There appeared to be a differential sensitivity of types of neuroglia to ionizing radiation. Oligodendroglia were more sensitive than astrocytes since astrocytes could be found in areas devoid of oligodendroglia throughout the entire experimental period. Although astrocytes were present, some differed from those in the control sections: nuclei were hyperthrophied and the processes as coarse and fibrillar. The inability to stain normal astrocytes in control sections under the same conditions suggests that impregnation by gold chloride is enhanced by irradiation. Widespread alterations in large ventral horn cells were not seen. After irradiation, some of the cells continued to develop and maturation, as seen by acquisition of Nissl substance, was not inhibited. In view of the marked paralysis in some animals, absence of lesions in somatic motor neurons of the ventral horn is surprising.

• Research Organization: Univ. of Arkansas, Little Rock
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-035522
• OSTI ID: 4645472
• Journal Information: Journal of Neuropathology and Experimental Neurology, Journal Name: Journal of Neuropathology and Experimental Neurology Journal Issue: 2 Vol. 22; ISSN 0022-3069
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AGE
CYTOLOGY
DYES
GOLD CHLORIDES
HEMORRHAGE
NERVOUS SYSTEM
RADIATION INJURIES
RATS
TISSUES
X RADIATION