The current literature documents a wide range of individ- ual effects of both estrogen and serotonin, which have been successfully used to explain both normal and patho- logical processes. E2, for example, initiates the develop- ment of the female reproductive system, influences the deposition of body fat, regulates the production of prolac- tin and other hormones, and increases sodium and water retention [41]. Independent of estrogen, serotonin regu- lates urination, influences the production of cerebrospi- nal fluid, and relaxes vascular smooth muscle [42]. These effects can be accounted for without reference to the inter- action between E2 and serotonin. However, we hypothe- size that considering how estrogen's actions might be mediated by serotonin.
