A 30-day treatment with DHT that enhanced neurogenesis in male rats had no effect on neurogenesis in young or middle-aged female rats . This result contradicts findings that an acute dose of estradiol has no effect on cell proliferation among mice or voles 97,104,108, and this discrepancy may be due to either an age effect (young vs. middle-aged) or duration of dosing. There is also evidence that low doses of testosterone have no effect on the survival of new neurons, based on both 30 days of injections (0.125 mg/rat) and testosterone implants that produced a low dose for 26 days . However, 30 days of a high physiological dose of testosterone (0.500 mg/rat) enhanced neurogenesis , which would suggest that different doses of testosterone influence the different stages of neurogenesis in different ways. The neuroprotective properties of androgens involve activation of the mitogen-activated protein kinase (MAPK) pathway 201,202, and the MAPK pathway has been shown to induce increased neuron survival in a wide range of contexts 203,204. Although some of the neuroprotective properties of testosterone may occur through aromatization to estradiol , evidence indicates that neuroprotection also occurs via androgen-dependent pathways 199,200. The lack of an effect of DHT specifically, may be because testosterone is influencing BDNF after being converted to estradiol. Louissaint et al. (2002) provided evidence indicating that testosterone enhances production of vascular endothelial growth factor (VEGF) within the HVC, while also increasing the number of VEGF receptors on local capillary beds . Another important factor seems to be the strain of rats used, as high levels of AR expression were found in the dentate gyrus of Wistar rats 102,162, low levels were observed in Sprague-Dawley rats 105,171, and no AR expression was observed in the dentate gyrus of Fischer 344 and Long-Evans rats . If you exercise, you find it easier to sleep and to keep a healthy weight. Prolonged endurance exercise especially can cause your testosterone to drop. When it comes to increasing your testosterone, quality sleep, physical activity, and weight management come first. Do you spend your holidays sitting by the pool, cocktail in hand? Ever wondered what the differences are between our best-selling energy supplements? 5 supplements that WILL help you conquer more However, testosterone replacement had no effect on a stress-induced decrease in cell proliferation or the number of DCX-expressing cells in the dentate gyrus among male mice . In general, acute and chronic stress cause a decrease in adult neurogenesis , and this effect is likely mediated through elevated glucocorticoid levels caused by stress 218,219. In support of this hypothesis, castration of male rats was found to increase levels of multiple protein markers of apoptosis, including caspase-3 . Androgens may, therefore, activate the MAPK pathway to have anti-apoptotic effects , which, in turn, increase the survival of newly developing neurons in the adult brain. The resultant increase in angiogenesis led to elevated production of BDNF by endothelial cells, which may, in turn, enhance neurogenesis within the HVC. In this article, we will delve into the role of TRT in enhancing performance, improving recovery, and optimizing overall health for individuals engaged in these demanding pursuits. If so, you may have heard about testosterone replacement therapy (TRT) and its potential benefits for men participating in adventure sports and endurance activities.
