Postnatal Production and Death of Cells in the Mouse Dentate Gyrus

Abstract

The data analyzed in the previous section indicate that the mouse dentate gyrus is characterized by a high level of proliferative activity throughout the whole period of postnatal ontogenesis. These findings agree with the results of previous investigations showing that in the dentate gyrus of both altricial mammals (mouse, rat, rabbit, cat) and precocial animals (guinea pig, rhesus monkey) a considerable part of neurons (and the majority of glial cells) appear after birth (Angevine 1965; Altman and Das 1965, 1967; Caviness 1973; Bayer and Altman 1974; Hine and Das 1974; Schlessinger et al. 1975; Kaplan and Hinds 1977; Stanfield and Cowan 1979b; Reznikov 1979, 1981; Bayer 1980a, 1982, 1985; Nowakowski and Rakic 1981; Rakic and Nowakowski 1981; Gueneau et al. 1982; Kaplan and Bell 1984; Wyss and Sripanidkulchai 1985; Crespo et al. 1986; Trice and Stanfield 1986; Eckenhoff and Rakic 1988). This clearly demonstrates the importance of the dentate gyrus as an object for experimental neurobiological and clinical investigations. The fact that most structures of the dentate gyrus appear during postnatal periods of development essentially simplifies experimental studies of morpho- and cytogenesis, formation of nerve connections, and the effect of exogenous factors on the development of this part of the central nervous system. The interest of clinicians becomes especially apparent in this case, since the dentate gyrus, due to its late development, represents one of the most vulnerable structures of the brain during the period when the developing brain of a child is not protected by the mother’s organism from environmental hazards (see Morgane et al. 1978 for a review).