On Some Cellular Reactions to X-Radiation

Abstract

The wall of the developing neural tube of young chick embryos contains two types of cells; one type, the germinal cells, with nuclei conspicuously active in mitosis, is restricted to the innermost layer of the neural wall; the other type of cell with nuclei in the resting state and none in division, forms the main mass of the neural wall, the mantle layer. A study of the neural tube after radiation with a single non-lethal dose of X-rays reveals a series of cellular changes: an initial period of mitotic depression during which mitotic figures in the germinal cells disappear entirely; a period of pseudo-recovery during which mitotic activity reappears ; a period of degeneration characterised by severe nuclear changes among the cells in the resting state ; and a period of remarkable regeneration and recovery resulting in a return of the tissue to its normal condition.