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Night owls vs. morning people: Who's smarter? - Yahoo! News

I’m a night owl.

Oxytocin – the love hormone – could cure shyness - Telegraph

Oxytocin … dubbed “the hormone of love” is known to increase empathy and bonding

oxytocin did improve powers of empathy – but only among those who were less socially proficient in the first place.

So if shyness is caused by a lack of social proficiency, it helps… in other words if people are shy because for whatever reason they are trapped in their own world, and not sufficiently immersed in the worlds of others this can help.

Stress Hormones Could Predict Boxing Dominance | Playbook

researchers took saliva samples minutes before two monkeys engaged in a staged competition for a pile of food. When dominant males won, there was a clear increase in the stress hormone right before the competition. In these cases, the dominant male was ready. He had sized up his opponent and knew, no doubt, that he’d prevail. Conversely, when the dominant male lost, the hormone level decreased before the food game. Although these apes live in very well-defined social societies – and the dominant male had more than likely battled with this opponent before and won – something had psyched him out.

Study suggests oxytocin makes people trusting, but not gullible

Serotonin cell discoveries mean rethink of depression (New Scientist)

psychotherapy:

If you thought depression was caused by low serotonin levels, think again. It looks as if the brain chemistry of a depressed person is much more complex, with mounting evidence suggesting that too much serotonin in some brain regions is to blame.

If correct, it might explain some of the negative side-effects associated with selective serotonin re-uptake inhibitors (SSRIs), antidepressants like Prozac which increase the amount of the neurotransmitter serotonin in some parts of the brain.

The traditional view of depression was largely based on the observation that SSRIs boost mood- although why they do so is unknown. “Because antidepressants increase serotonin in some parts of the brain, people assumed that depression must be the result of low serotonin levels,” says Christopher Lowry of the University of Boulder in Colorado. But the discovery of multiple types of serotonin-releasing neurons in the brain, along with high levels of serotonin recorded in people with depression, is prompting a rethink.

“What’s more likely is that there are subgroups of serotonin neurons that are overactive in depressed patients, rather than underactive as we have all been assuming,” says Lowry.

One of the first clues that something might be amiss with the traditional theory came three years ago, when Murray Esler at the Baker Heart Research Institute in Melbourne, Australia, and colleagues found that the level of serotonin in the brains of people with panic disorder was four times higher than in healthy volunteers (Stress, DOI: 10.1080/10253890701300904), and in depressed people who were not receiving treatment it was two times higher than in volunteers (Archives of General Psychiatry, vol 65, p 38). They also showed that long-term use of SSRIs in people with depression and panic disorder seemed to decrease serotonin levels through an as yet unidentified mechanism.

Now, in studies of rats and mice, Lowry has found that there are multiple types of serotonin neurons that can be independently regulated. He presented his results at the Forum of European Neuroscience in Amsterdam, the Netherlands, last week.

This fits well with findings from other groups that there are two types of serotonin receptor in the amygdala, a brain region linked to emotion and anxiety: 5-HT2A receptors that inhibit anxiety, and 5-HT2C receptors that promote it. The roles of the receptors were identified by injecting drugs that either stimulated or inhibited each receptor and observing the animals’ behavioural response.

Together, the findings might mean that while high levels of serotonin in some brain regions like the prefrontal cortex can lead to improved mood, high serotonin in other regions could have negative effects.

Evidence for this idea comes from Gina Forster at the University of South Dakota in Vermillion and colleagues, who injected a stress-related molecule into the brains of rats and found that it triggered two phases of serotonin release. An initial wave of serotonin appeared to increase fear-like behaviour in the rats, while a second wave decreased this behaviour, possibly because it activated a brain region called the medial prefrontal cortex, which is associated with calming of fears (Neuroscience, vol 141, p 1047).

The new findings have implications for how SSRI drugs work. In the long-term, SSRIs do tend to have a calming effect, although more research is needed to understand how they do this.

However, in the short-term some people taking SSRIs report feeling increased anxiety. This is “almost certainly due to the activation of one of these groups of serotonin neurons”, says Lowry. The suicidal thoughts some people taking SSRIs claim to experience may also be linked to boosting serotonin, as suicide is thought to be associated with increased impulsivity. “It may be that certain types of SSRI are affecting these impulsivity circuits in the brain,” says Lowry.

Learning more about these different groups of serotonin neurons could lead to better treatments for depression and anxiety disorders. “It might be possible to design very specific drugs that can turn on or off specific groups of neurons that are deregulated in anxiety or depression,” says Lowry.

powerfully important - for those who care about these sorts of things.

Ketamine is a Very Effective Anti-Depressant (CalorieLab Lab Notes)

An anti-depressant usually takes weeks to take effect if it works at all and people often have to try different ones, while ketamine was able to fight off depression in a matter of hours. In rats, connections between neurons injured by long term stress were restored by ketamine. A study done by the National Institute of Mental Health showed that 70 percent of people for whom other types of anti-depressants did not work improved within hours of receiving ketamine. Drawbacks to using it are intravenous administration and sometimes short-term psychotic behavior occurs.