Higher Testosterone In Boys Reflective Of Lower Executive Function

[alywest]

Developmental effects of androgens in the human brain.
Neuroendocrine theories of brain development posit that androgens play a crucial role in sex-specific cortical growth, although little is known about the differential effects of testosterone and dehydroepiandrosterone (DHEA) on cortico-limbic development and cognition during adolescence. In this context, the National Institutes of Health Study of Normal Brain Development, a longitudinal study of typically developing children and adolescents aged 4-24 years (n=433), offers a unique opportunity to examine the developmental effects of androgens on cortico-limbic maturation and cognition. Using data from this sample, our group found that higher testosterone levels were associated with left-sided decreases in cortical thickness (CTh) in post-pubertal boys, particularly in the prefrontal cortex, compared to right-sided increases in CTh in somatosensory areas in pre-pubertal girls. Prefrontal-amygdala and prefrontal-hippocampal structural covariance (considered to reflect structural connectivity) also varied according to testosterone levels, with the testosterone-related brain phenotype predicting higher aggression levels and lower executive function, particularly in boys. By contrast, DHEA was associated with a pre-pubertal increase in CTh of several regions involved in cognitive control in both boys and girls. Covariance within several cortico-amygdalar structural networks also varied as a function of DHEA levels, with the DHEA-related brain phenotype predicting improvements in visual attention in both boys and girls. DHEA-related cortico-hippocampal structural covariance, on the other hand, predicted higher scores on a test of working memory. Interestingly, there were significant interactions between testosterone and DHEA, such that DHEA tended to mitigate the anti-proliferative effects of testosterone on brain structure. In sum, testosterone-related effects on the developing brain may lead to detrimental effects on cortical functions (ie, higher aggression and lower executive function), whereas DHEA-related effects may optimise cortical functions (ie, better attention and working memory), perhaps by decreasing the influence of amygdalar and hippocampal afferents on cortical functions.

 

[mujuro]

I wonder how this may cross over with mood disorders and schizophrenia, which are consistent with both executive dysfunction and neuroendocrinological alterations, specifically reduced hippocampal volume (more pronounced in schizophrenia) and HPA dysfunction.

 

[Nicolas Noyola]

this is an interesting post tbh, I had a similar thread a while back: "Androgens In Human Evolution"
some guy, whose profession is unknown to me (but presumably some sort of scientist), postulates all these ideas regarding the relationship between DHEA and testosterone, evolution, and human brain size.

there are studies though that show the positive influence of testosterone on intelligence, mostly nonverbal intelligence and processing speed, stuff like that, intellectual domains that you could conceive of as more masculine.
I'm sure the nuances are beyond my knowledge and understanding

“Effect of injection of testosterone derivatives to pregnant rats on the brain of their one-day offspring” B.Y.Ryzhavskii

“Intramuscular injection of Sustanon-250, a drug with testosterone derivatives of various action rate and duration, to rats on day 19 of gestation affected brain development in their offspring. This effect manifested in greater brain weight and neocortex thickness, smaller density of neurons in the developing cortical layer V, and larger size of these neurons and their nuclei and cytoplasm in comparison with control neonatal rats. These data attest to accelerated cerebral development in the offspring of experimental rats in comparison [to] offspring of control rats.”

Bulletin of Experimental Biology and Medicine 2002; 134: 509-11

 

[Nicolas Noyola]

"Prior to the increase in bran size, the bodies of hominids would be increasing in size. Testosterone directs the use of DHEA for this growth. With the advent of increasing brain size, use of DHEA is increased by the brain. (I think growth and development of the brain requires more DHEA than body size. That is, the brain competes for available DHEA at the expense of other tissues.) Therefore, at this stage in human evolution, DHEA is being used for growth and development of the brain, again, at the expense of the body. I suggest this is the cause of a switch from “robust” hominids to “gracile” hominids. The brain grows bigger at the expense of the face, teeth, and jaws. Stedman, et al., suggest the change in myosin is involved in this change. I suggest Stedman, et al., are correct that this may have occurred at the critical time, that is, a time when masseter muscle size was declining approximately at the same time brain enlargement was increasing. However, I suggest the change in myosin may be due to the changing ratio of DHEA to testosterone that was driving human evolution."

So basically increased intelligence is due to a shifting in the allocation of energy and hormones, according to him?
I remember I once rubbed Pansterone on my forehead and temples, in a frustrated attempt to surmount a brain-block during math . I just ended up getting really sleepy.

 

[baccheion]

"Prior to the increase in bran size, the bodies of hominids would be increasing in size. Testosterone directs the use of DHEA for this growth. With the advent of increasing brain size, use of DHEA is increased by the brain. (I think growth and development of the brain requires more DHEA than body size. That is, the brain competes for available DHEA at the expense of other tissues.) Therefore, at this stage in human evolution, DHEA is being used for growth and development of the brain, again, at the expense of the body. I suggest this is the cause of a switch from “robust” hominids to “gracile” hominids. The brain grows bigger at the expense of the face, teeth, and jaws. Stedman, et al., suggest the change in myosin is involved in this change. I suggest Stedman, et al., are correct that this may have occurred at the critical time, that is, a time when masseter muscle size was declining approximately at the same time brain enlargement was increasing. However, I suggest the change in myosin may be due to the changing ratio of DHEA to testosterone that was driving human evolution."

So basically increased intelligence is due to a shifting in the allocation of energy and hormones, according to him?
I remember I once rubbed Pansterone on my forehead and temples, in a frustrated attempt to surmount a brain-block during math . I just ended up getting really sleepy.

Would this corrected by increasing magnesium (associated with DHEA levels) or pregnenolone during development? What about via increasing metabolism, as T3 and vitamin A are the main cofactors involved in conversion of cholesterol to pregnenolone?

 

[Nicolas Noyola]

Would this corrected by increasing magnesium (associated with DHEA levels) or pregnenolone during development? What about via increasing metabolism, as T3 and vitamin A are the main cofactors involved in conversion of cholesterol to pregnenolone?

I'm sure it depends on the person. that guy makes alot of unsubstantiated assumptions I think, after reviewing his work tbh, but overall it's an interesting theory that makes sense to me on a few levels. I don't know if there's anything to 'correct' either. correction implies some sort of deficiency, but the way he writes about it, he seems to be saying the increased DHEA is an adaption, basically your brain consumes more DHEA than other tissues. but there are some individuals who have robust bodies and skeletons but also great intelligence; in those individuals I would presume excellent health, abundant nutrition and calories right? health excellent enough such that they have enough DHEA to support an excellent brain, but also a robust body. So in that sense yeah, if you take things that increase DHEA, I'm sure some of the increase in DHEA will go to your body rather than solely your brain. but this is just a theory, and i wouldn't put too much stock in it tbh, its just interesting from a peatian perspective, and the guy cites some interesting studies

 

[alywest]

Perhaps it still has to do with estrogen, based on what is in this study. However, testosterone was still required to become estrogen. I wasn't aware that there is aromatase in the brain.

Androgen actions on central serotonin neurotransmission: relevance for mood, mental state and memory.
Sex steroids exert potent effects on mood and mental state in the human. Our previous experimental findings in female rats suggest that these effects may be mediated, in part, by the action of estrogen on the 5-hydroxytryptamine2A receptor (5-HT(2A)R) and serotonin transporter (SERT) in brain. Here we review our recent findings on the effect of acute (approximately 32 h) testosterone manipulation on central 5-HT(2A)R and SERT in male rats. Castration decreased while testosterone or estrogen, but not 5alpha-dihydrotestosterone (5alpha-DHT), increased significantly the content of 5-HT(2A)R mRNA and SERT mRNA in the dorsal raphe nucleus (DR) and the density of 5-HT(2A)R and SERT binding sites in higher centers of the brain. The lack of effect of 5alpha-DHT, a potent androgen which cannot be converted to estrogen, suggests that the action of testosterone depends upon its conversion to estrogen by aromatase. This may also explain why estrogen, but not testosterone or 5alpha-DHT, increased the density of 5-HT(2A)R binding sites in the caudate-putamen, a brain region where aromatase is scarce. The estrogen induction of SERT mRNA is most prominent in the rostral DR and this together with the correlation between sensitivity of DR serotonin neurons to estrogen and neurotoxic amphetamine derivatives provides a potential topochemical handle with which to investigate testosterone/estrogen regulation of SERT gene expression. These findings are discussed in relation to the possible role of interactions between sex steroids and serotonin mechanisms in mood disorders, schizophrenia and Alzheimer's disease.

 

[alywest]

this is an interesting post tbh, I had a similar thread a while back: "Androgens In Human Evolution"
some guy, whose profession is unknown to me (but presumably some sort of scientist), postulates all these ideas regarding the relationship between DHEA and testosterone, evolution, and human brain size.

there are studies though that show the positive influence of testosterone on intelligence, mostly nonverbal intelligence and processing speed, stuff like that, intellectual domains that you could conceive of as more masculine.
I'm sure the nuances are beyond my knowledge and understanding

“Effect of injection of testosterone derivatives to pregnant rats on the brain of their one-day offspring” B.Y.Ryzhavskii

“Intramuscular injection of Sustanon-250, a drug with testosterone derivatives of various action rate and duration, to rats on day 19 of gestation affected brain development in their offspring. This effect manifested in greater brain weight and neocortex thickness, smaller density of neurons in the developing cortical layer V, and larger size of these neurons and their nuclei and cytoplasm in comparison with control neonatal rats. These data attest to accelerated cerebral development in the offspring of experimental rats in comparison [to] offspring of control rats.”

Bulletin of Experimental Biology and Medicine 2002; 134: 509-11

Are you familiar with this paper?
Extreme male brain theory of autism