Anabolic steroids, depression, BDNF & morning corticosterone levels


Abuse of anabolic androgenic steroids (AASs) is frequently associated with changes in mood, including depression. [...] We used male adult rats injected for 4 weeks with either nandrolone or stanozolol at daily doses (5 mg/kg, s.c.) that are considered equivalent to those abused by humans [...] AAS treatment reduced levels of brain-derived neurotrophic factor in the hippocampus and prefrontal cortex, reduced the expression of low-affinity glucocorticoid receptors in the hippocampus, and increased morning trough basal plasma corticosterone levels. All these changes have been related to the pathophysiology of major depressive disorder. Accordingly, rats treated with nandrolone or stanozolol showed an increased immobility time in the forced swim test, which is widely used for the screening of antidepressant drugs. All effects produced by AASs were prevented by co-administration with the classical antidepressant, chlorimipramine. (via.)


East & Western Cultural Values: Honesty, Dominance & Submission


When an American thinks about whether he is honest, his brain activity looks very different than when he thinks about whether another person is honest, even a close relative. That’s not true for Chinese people. When a Chinese man evaluates whether he is honest, his brain activity looks almost identical to when he is thinking about whether his mother is honest.

That finding — that American and Chinese brains function differently when considering traits of themselves versus traits of others (Neuroimage, Vol. 34, No. 3) — supports behavioral studies that have found that people from collectivist cultures, such as China, think of themselves as deeply connected to other people in their lives, while Americans adhere to a strong sense of individuality.

Different study, but from the same article:

Ambady’s group based the study on historical data showing that East-Asian cultures value submissiveness, while Western cultures value dominance. In fact, they found, they could see this cultural distinction in the way the brain responds to visual input. When Americans viewed dominant silhouettes, but not submissive ones, reward circuitry fired in the brain’s limbic system. The opposite happened among Japanese participants; their reward circuitry fired in response to submissive, but not dominant, silhouettes.

… same article:

Most recently, a study by Park’s group, in press in Social Cognitive and Affective Neuroscience demonstrated that Westerners process human faces more actively than East Asians, consistent with the Western focus on individuality.

… last interesting tidbit:

The researchers sought to find a biological explanation for past research showing that people from collectivist cultures relate more strongly to contextual self-descriptions, such as “When I’m with my mother, I’m honest.” People from already defined individualistic cultures relate more strongly to general self-descriptions such as “I’m honest.”

When Chiao and her colleagues compared participants along ethnic lines, they saw no difference in brain activity. Differences appeared only after they grouped people based on how strongly they valued collectivism or individualism: Regardless of ethnicity, the medial prefrontal cortex was most active when individualists read general self-descriptions and when collectivists read contextual self-descriptions.

via.


Atypical Brain Functioning in Siblings of Autistics


Relative to the other groups, there was reduced activity in specific brain regions in children with ASD when they were watching biological motion compared with scrambled motion.

These included the right amygdala and the ventromedial prefrontal cortex, areas which other research has identified as having changed activity in adults with ASD.

The researchers found additional brain regions that showed reduced activity in both the siblings group and the ASD group, relative to the typically developing group.

They interpreted this result as a reflection of the underlying genetic vulnerability that the siblings group might have to ASD.

The scientists also found what they called “compensatory activity” in the siblings group – brain regions that were working harder than normal and might be helping the children overcome their increased genetic risk of ASD.

These included the right posterior temporal sulcus and the ventromedial prefrontal cortex, which have been implicated in social perception and social cognition. [...]

“More controversially, the authors also propose that other brain regions are under-responsive to biological motion in siblings of children with autism, as well as in those with autism.”

“Yet other regions are reported to be overactive in the siblings, and this is interpreted as compensatory activity.
“Since these siblings had no subclinical symptoms of autism, and were selected to have no other relatives with any autistic features, they are unlikely to constitute a group with strong genetic risk for autism, and so this aspect of the results is puzzling and it would be important to replicate it in another sample.” (via.)

It’s interesting that while autistics show below normal activation in the ventromedial prefrontal cortex, that their siblings showed above normal activation in the same region while viewing “biological motion.”

It’ll be interesting to see what mysteries of the human mind will be revealed as the diagnostic criteria for what exactly defines the autistic spectrum becomes more refined. Supposedly these autistic children didn’t have any other relatives showing symptoms of autism, however, wouldn’t it be interesting to find out whether their relatives show this same abnormal overactivation in said regions.


Close Friends Light up Medial Prefrontal Cortex more than Strangers


The research subjects’ brain regions responded more to questions regarding their close friends than they did to strangers with similar interests. The experiments attempt to show that social closeness is used more than similarity of beliefs when evaluating others in some tasks relying on the medial prefrontal cortex region of the brain. (via.)


Brain abnormalities in adolescents with substance abuse & conduct disorders


The scientists, including collaborators at the University of Colorado at Boulder and the University of Maryland, studied 20 adolescent boys. On average they had been on probation 139 of the last 180 days; 19 of the 20 had the psychiatric diagnosis of conduct disorder, and all had diagnoses of substance use disorder. They had been abstinent, however, an average of about five weeks when studied. They were compared with 20 other boys who did not have serious antisocial or drug problems, but who were of similar age, ethnicity, and home neighborhoods.

All played a computerized risk-taking game that repeatedly presented a choice between a cautious and a risky behavior: press the left button and always win one cent, or press the right button and either win five cents or lose ten cents. The scientists examined brain activation with functional magnetic resonance imaging (fMRI) as the boys decided to press right or left, and then as they experienced wins or losses after right presses.

Brain activation differed dramatically in the two groups. The anterior cingulate cortex monitors changing rewards and punishments, and then sends that information to another brain region (dorsolateral prefrontal cortex), which regulates one’s choices among possible behaviors. During decision-making, antisocial boys had significantly less brain activity than normals in both of those regions, and also in other decision-making areas (orbitofrontal cortex, amygdala, insula).

via.