Histopathologic Effect of High-Energy-Particle Microbeams on the Visual Cortex of the Mouse Brain
A histopathologic study was made of the radiogenic lesions produced in the mouse visual cortex with highenergy-particle beams 1 mm, 0.250 mm, 0.075 mm, and 0.025 mm in diameter. Irradiation with the smallest microbeams results in a complete and definite destruction of nerve cell bodies only. Irradiated nerve fibers are not destroyed; neither is there permanent damage to vessels. Interstitial glia cells are partly preserved. The dosages necessary to produce such a lesion in 24 days are extremely high, 400,000 rads for a 0.025-mm beam. The threshold dose is very constant. This is in contrast to lesions produced by larger beams. Here, either total tissue necrosis results from the irradiatlon, or destruction of nerve cell bodies is very scant and patchy in distribution. Acute circulatory disturbances and delayed radiation damage of vessels are constant findings. The dosage required to produce a complete destruction of nerve cells withln 24 days is 14000 rads for 1-mm beams, but this dose also renders the other tlssue components necrotic. This threshold dose has a wide range from 9300 rads to 26000 rads. From the observations it is apparent that, the larger the irradiated tissue volume, the greater are the fluctuations in tissue radiosensitivity; and that tissue radiosensitivity is inversely related to the tissue volume being irradiated. Radiosensitivity of mouse brain cortex to 1- mm beams seems to be largely determined by the radiosensitivity of the vascular apparatus; direct nerve cell necrosis by radiation appears to be of secondary importance but it is demonstrable. Wlth microbeam irradiation the radiosensitivity seems to be determined exclusively by the radiosensitivity of the nerve cells themselves.
- Research Organization:
- Brookhaven National Lab., Upton, N.Y.; and Indiana Univ., Indianapolis
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-15-032040
- OSTI ID:
- 4838575
- Journal Information:
- Radiation Research, Vol. 15, Issue 4; Other Information: Orig. Receipt Date: 31-DEC-61; ISSN 0033-7587
- Publisher:
- Radiation Research Society
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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