Testosterone is a hormone which, although also present in women, appears in the collective imagination as the main substance associated with the male. Since its discovery, it has been linked to aggression, competitiveness, muscle and physical development, and sexual appetite. We know that all of this is influenced by the action of this hormone.
But … How does testosterone affect the brain? Various researches make it possible to know the implication of this substance in the functioning of the male nervous system.
What is testosterone?
Testosterone is a steroid-like hormone, Which penetrates through the cell membrane and binds to certain proteins and passes with them to the nucleus to synthesize different proteins.
It is also one of the main sex hormones that is part of the androgen group. It is a key substance for development and is involved in a large number of processes. Among them, he underlines its great importance for sexual development (both primary and secondary sexual characteristics of men depend largely on this hormone) and in libido or sexual desire.
But their functions are not only sexual, but it also has an effect on cognitive skills, on emotions, on growth and the formation of bones and muscles and in the state of mind.
The main organs that release testosterone are the testes, that release Leydig cells along with other hormones. This release is governed by the pituitary gland, located in the brain. However, the testes are not the only organ that secretes testosterone. In fact, both men and women have testosterone (although the latter to a lesser extent). Indeed, certain cells of the adrenal glands synthesize it and also release it, and certain ovarian cells in the case of women.
Although it is secreted naturally, in some people with different problems treatments with synthetic testosterone may be performed. This is the case for people suffering from hypogonadism, certain biological causes of erectile dysfunction or in hormone therapy practiced by people undergoing sex reassignment (in particular, in cases where the subject seeks to reassign himself to the male sex) . Patches of this hormone are also used to treat osteoporosis and decrease sexual desire. They have also been used in other areas, such as sports, although their use is considered doping.
Testosterone is a hormone that works at different levels and in different brain structures. Research reveals that specifically causes an increase in the activity of the limbic system in the brain, A set of parts of the brain involved in creating emotions.
In this sense, it is especially the amygdala, hypothalamus or periaqueductal gray matter that are affected by testosterone, which makes it more responsive to stimulation. It should be noted that these brain areas are very linked to ancestral survival mechanisms, So that the aggressive response is activated as a means of ensuring its own safety.
In addition to this, testosterone has different mechanisms of action to promote and increase the production of different neurotransmitters. Specifically, it has been observed that the secretion of dopamine and acetylcholine is strongly influenced by testosterone levels.
Effects of testosterone on the brain
Testosterone has a number of very important effects on the brain which in turn cause different effects on an individual’s behavior and abilities. Several are specified below.
1. Increases the level of aggression and competitiveness
The action of testosterone on the amygdala and the limbic system in general provokes the manifestation of the subject high reactivity to external stimuli, eliciting aggressive reactions easier. It has also been observed that when the concentration of this hormone increases, the level of competitiveness of the subjects tends to be higher.
2. It is related to energy
The higher presence of testosterone in men is also associated with a higher level of energy and activity. This relationship is two-way: testosterone can make us more active, but at the same time the more active we are, the more testosterone we generate. This fact recommends them to exercise frequently for people who have low levels of this hormone.
3. Boost libido
Another of the best known and most visible effects of this sex hormone is precisely the increase in libido. In both men and women. In fact, patches of this hormone are often prescribed for women who have lost their sexual appetite after menopause.
4. It has an influence on mood and anxiety
By increasing the production of dopamine, testosterone has an effect on maintain the mood and in the sensations of pleasure. Men with low testosterone tend to have more depressive symptoms. Likewise, they also tend to show a higher level of anxiety than subjects with normative or high levels.
5. It can decrease the capacity for empathy
People with excessive amounts of testosterone may be less empathetic, more self-centered, and with less ability to bond emotionally. This is associated with a possible inhibitory effect of this hormone with oxytocin.
6. Effect on memory
As with dopamine, testosterone causes an increase in acetylcholine levels. Being a hormone involved in brain function, it can influence the ability to keep information in memory and subsequently evoke cognitive aspects such as memory.
7. Promotes neurogenesis
Different research suggests that the presence of testosterone causes the birth and growth of new neurons, especially in the case of the hippocampus.
- Janowsky, JS (2006). Think with the gonads: testosterone and cognition. Trends in Cognitive Science, 10 (2): 77-82.
- Zarrouf, FA; Artz, S .; Griffith, J .; Sirbu, C and Kommor, M. (2009). Testosterone and depression: systematic review and meta-analysis. Journal of Psychiatric Practice: 15 (4): 289-305.