Examination of Sexually Dimorphic Cell Death in the Pubertal Mouse Brain

A period of cell death during a critical period early in life is responsible for causing permanent structural changes to many brain areas, but it is not known whether cell death plays a role in brain organization outside of early postnatal life. Puberty is considered a second sensitive period because the brain is the target organ of gonadal hormones. This study looked at global and regional patterns of cell death during pre-puberty and puberty in the mouse brain. My findings show there is more cell death happening during pre-puberty than during puberty. Cell death does happen during puberty but at adult levels. Furthermore females at P20 have more dying cells than males globally and in the hippocampus, but no other sex differences were observed. Knocking out the Bax gene, which is important for neuronal death, had only a modest effect on cell death during pre-puberty and puberty compared to what has been shown in younger ages. My findings demonstrate that prepubertal animals have more cell death than pubertal animals. Also, since Bax gene deletion only had a modest effect on cell death, cell populations other than neurons may be dying during these periods