Relationship between brain cortex and testis maturation rate in two inbred strains of mice.

Two inbred strains of mice, SEC/1ReJ (SEC) and C57BL/6J (C57) showed significant differences in the maturation rate of two different anatomical districts: the brain cortex and the seminiferous epithelium. The cortical maturation rate, recorded by means of an electrocorticogram (ECoG), indicated that SEC mice are slower in the development of an adult wave pattern than C57 mice, which are more mature at birth. Furthermore, the C57 strain appears to have a faster maturation rate of the seminiferous epithelium. In fact, spermatogenesis in these mice shows the presence of spermatids in the seminiferous epithelium at 25 days, and mature spermatozoa in the epididymis at 40 days. Instead, the SEC strain, because of its slower development, shows a considerable delay of spermiogenesis and the epididymis is still empty at 40 days. These data, together with those on the ECoG differences of these strains, seem to indicate a relationship between brain and testis maturation.