社会的孤立
Social isolation has a hindering effect in AHN whereas normal regulation of androgens increases AHN. A study using male rats showed that testosterone may block social isolation, which results in hippocampal neurogenesis reaching homeostasis—regulation that keeps internal conditions stable. A Brdu analysis showed that excess testosterone did not increase this blocking effect against social isolation; that is, the natural circulating levels of androgens cancel out the negative effects of social isolation on AHN.