Testosterone is postulated to have a protective effect against the development of dementia, as evidenced by the higher incidence of Alzheimer disease (AD) in women, who make up two-thirds of AD patients. Progressive testicular atrophy causing oligospermia is seen in 80% of men with DM1 along with reduced adrenal androgen synthesis . Furthermore, testosterone supplementation along with exercise in patients with IBM led to an additional decrease in inflammatory response when compared to exercise alone . Preclinical models have demonstrated decreased adipose infiltration in DMD muscles and improved muscle function in female mice treated with oral selective AR modulators . Duchenne Muscular Dystrophy (DMD) is an X-linked recessive disorder causing progressive neuromuscular weakness primarily affecting males, typically manifesting in prepubertal boys. Another study found that androgen supplementation led to muscle growth but worsened motor neuron death and survival. While sex steroids are most often discussed in relation to romantic and sexual brain circuits, they are certainly not limited to those areas. You may remember learning about estrogen and testosterone in middle school health class. While some beliefs about male and female behavior are rooted in outdated gender stereotypes, we know that sex and gender identity are distinct concepts – and operate on different spectrums. There are some evidences supporting the hypothesis that testosterone may act protectively in neurodegenerative disorders, e.g. One of the less known testosterone actions is neuroprotection. Furthering our knowledge of neurotransmitter systems involved in mental and neuropsychiatric disorders will be crucial to understanding how E2 impacts these systems and how it may be utilized to target therapeutic approaches for impairments in the serotonergic, dopaminergic, and glutamatergic systems. Expanding research to include diverse populations with varying age ranges, sex and gender identities will allow for the most comprehensive analysis of future data. Moreover, the investigation on how the estrogenic regulation of this neurotransmitter systems may affect or underlie pathophysiological states needs to be further explored. However, the wisdom and effectiveness of testosterone treatment to improve sexual function or cognitive function among postmenopausal women is unclear. Testosterone therapy may make sense for women who have low testosterone levels and symptoms that might be due to testosterone deficiency. Also, as men get older, their livers make more sex hormone binding globulin (SHBG), which binds to testosterone circulating in the bloodstream. In fact, as men age, testosterone levels drop very gradually, about 1% to 2% each year — unlike the relatively rapid drop in estrogen that causes menopause. The proper balance between testosterone (along with other androgens) and estrogen is important for the ovaries to work normally. These hormones are thought to have important effects on This modulation can affect the dopaminergic responsivity within the nigrostriatal system, an area that plays a significant role in movement and reward. Testosterone has the potential to influence brain activity, specifically within regions like the substantia nigra and the ventral tegmental area, which are essential for dopamine production and regulation. Testosterone interacts with dopamine, a neurotransmitter, in complex ways affecting both your brain and body. These hormones interact with each other and influence various bodily functions, revealing a complex interplay essential for overall health and behavior. Studies have indicated that testosterone can impact behaviors and might be involved in neurological conditions, thereby affecting the brain’s neurochemistry and influencing functions such as anxiety, depression, spatial abilities, and memory. The effects of testosterone extend beyond mere physical attributes, reaching into the realms of cognition and mood regulation. This means that not only does testosterone affect the release and regulation of dopamine, but dopamine also influences the secretion of testosterone, highlighting a reciprocal relationship that is crucial for various bodily functions. Androgen receptors (ARs) are expressed through a gene located on chromosome X and remain cytoplasmic in the inactive state. In women, a minute amount of testosterone is produced following peripheral conversion of DHEA and androstenedione in the liver, skin, muscles, and fat tissue. In men, a small amount of testosterone is converted into estradiol in adipose tissue, bones, and brain. It is responsible for formation of external male genitalia in fetus, prostate growth, and plays a role in male pattern baldness. Testosterone is the most potent androgen, produced primarily by the Leydig cells in the testis. Interestingly, the enzyme 5 alpha-reductase, involved in the metabolism of testosterone to its more potent form dihydro-testosterone, is mainly concentrated in the white matter. The term "neuroactive steroid" corresponds to a functional concept and refers to natural hormonal steroids, produced by the nervous system or the peripheral glands, and to synthetic steroids, that modify the activity of neural cells. They are not only produced by the adrenal glands, ovaries and testes and transported to the nervous system , but they are also synthesized within the nervous system of both males and females throughout life.
