Neural injections of Bromodeoxyuridine (BrdU) were applied to males of both groups to test for neurogenesis . Analysis showed that testosterone and dihydrotestosterone regulated adult hippocampal neurogenesis (AHN). Adult hippocampal neurogenesis was regulated through the androgen receptor in the wild-type male rats, but not in the TMF male rats. To further test the role of activated androgen receptors on AHN, flutamide , an antiandrogen drug that competes with testosterone and dihydrotestosterone for androgen receptors , and dihydrotestosterone were administered to normal male rats. Dihydrotestosterone increased the number of BrdU cells, while flutamide inhibited these cells.
Note that it is well possible to eliminate the need for sports supplements completely, simply by eating large enough quantities of poultry, meat and fish. By eating 2 to 3 lbs of poultry, meat or fish per day you fully cover your daily needs of quality protein and creatine, eliminating the need for any supplementation. Eating such high amounts of poultry, meat and fish can, however, have a few disadvantages: poultry, meat and fish can contain lots of saturated fats, cholesterol and pollutants, they can be rather costly, and take lots of time for preparing and eating.