Dispersion of cisternae of rough endoplasmic reticulum in aging CNS neurons: a strictly linear trend.

Dispersion of cisternae of rough endoplasmic reticulum (RER) in aging rats has been determined quantitatively for mitral cells of the olfactory bulb and Purkinje cells of the cerebellum using a recently published morphometric technique (Cruz Orive, '76). In both cell types dispersion of cisternae occurred throughout the period studied and in a linear fashion. The observed RER dispersion cannot be attributed to a decrease in the total amount of RER, since the total amount of RER was constant in Purkinje cells and increased in mitral cells during the age studied.