Does melatonin do anything at all? Placebo effect, perhaps?


The U.S. Department of Health and Human Services released information today about research on melatonin supplements. The research was conducted at the University of Alberta for the U.S. National Center for Complementary and Alternative medicine. U of A researchers did a comprehensive review of all studies on the use of melatonin supplements to treat sleep disorders.

Click here to read the synopsis of what they found. Not looking so good for melatonin, me thinks!


Endogenous melatonin, cortisol, and b-endorphin levels after a marathon


Strenuous exercise increases plasma melatonin, cortisol, and ?-endorphin concentrations. Furthermore, a relationship between endogenous opioids and melatonin has been proposed. We measured plasma melatonin, cortisol, and ?-endorphin in 46 subjects before and after a 28.5-mile high altitude race. Thirteen of the subjects received the orally active opioid antagonist naltrexone immediately before the race. The mean plasma melatonin, cortisol, and ?-endorphin levels were higher after the race than before it; the melatonin results were confirmed by gas chromatography-mass spectrometry assay of 12 subjects. Naltrexone had no effect on the increase in any of the three hormones. (via.)

This study was briefly mentioned in “DMT: The Spirit Molecule.” I happened to run across it and thought I’d tuck it away on the blog in case it ever comes up again for some reason.


Helicobacter pylori bacteria linked with Parkinson’s (mice)


The bacteria responsible for stomach ulcers have been linked to Parkinson’s disease, according to researchers in the US.

Mice infected with Helicobacter pylori went onto develop Parkinson’s like symptoms.

The study, presented at a meeting of the American Society for Microbiology, argues that infection could play “a significant role”.

Read more at the BBC.


Importance of Breakfast: Mood, Anxiety, Depression and More


I’ve been skipping breakfast a lot lately, and that hasn’t been my habit in years past. It occurred to me after reading 4 Hour Work Week by Timothy Ferris (who advocates a high protein meal in the morning) that I may be doing some legitimate harm to myself.

This study isn’t exactly my age group, but I think it might still be applicable… I’ll consider myself a student of life until I’m dead. Maybe I should consider making an effort to grab breakfast in the morning? See below:

Conducted in public schools in Philadelphia and Baltimore, the study found that increased school breakfast participation correlated with less tardiness and absence, higher math grades, and reductions in problems like depression, anxiety and hyperactivity. The researchers also found that students were more like to participate in school breakfast programs when the meals were offered free to all students, compared with programs that provided free meals to low-income youngsters while others paid for their breakfasts. [...]

They also showed greater improvement in student-reported levels of depression and anxiety and, for the Baltimore students, reduced levels of hyperactivity, as reported by teachers. (via.)


Cognitive Science / Neuroscience Blog List (up-to-date)


I’m looking to connect up with some of the other neurobloggers out there. No better way than to give a pingback shoutout, so I’m checking all of the blogs listed on Neurophilosophy’s list from 2007, and removing dead links. If any of you guys are looking for a fresh smattering of neuro blogs to add to your rss reader, dive right in!

Advances in the History of Psychology
All In The Mind
Mempowered!
Action For Autism
Addiction & Recovery News
International Cognition and Culture Institute
Asperger’s Conversations
Babel’s Dawn
BioLaw
Björn Brembs
Body in Mind
BrainBlog
Brain Hammer
Developing Intelligence
Ginger Campbell, MD
Brain Windows
The Corpus Callosum
Channel N
Dr. Deb Psychological Perspectives
Dr. Helen
Dr. Sanity
Dr. X’s Free Associations
Eide Neurolearning Blog
Figural Effect
Functional Neurogenesis
PsychoBabble
Improve Your Learning and Memory.
IQ’s Corner
Laura’s Psychology Blog
Meeting of the Mind
Mike Battista
Mind Hacks
my mind on books
Neurobot
Neurochannels
Neuroethics at the Core
NeuroKüz
Neurological Correlates
NeuroDojo
Neurdon
neurodudes
Neurology Minutiae
Neurologica Blog
Neuronarrative
neuropathology blog
Neurophilosophy
Neuroskeptic
NeuroWhoa!
Omni Brain
On the Brain
Oscillatory Thoughts
Panic!
Prof Zeki’s Musings
Providentia
PsychCentral
The Psychiatrist Blog
Psychology of Pain
Shrink Rap
ShrinkWrapped
Steve’s Blog (OkaySteve)
Talking Brains
The Beautiful Brain
The Mouse Trap
The Nerve Blog
The Neurocritic
The Neuro Times
The Tangled Neuron
Tic Toc Talk: The IQ brain clock
Transmuted Internalizations
Brain Injury Lawyer & Attorney
We’re Only Human
Wiring The Brain

Needless to say, quite a few were removed from Neurophilosophy’s original list. A lot of them were no longer being updated.


Serotonin: Human social intimacy/connection and romance


Healthy adult volunteers, whose levels of serotonin activity had been lowered, rated couples in photos as being less intimate and less romantic than volunteers with normal serotonin activity.

The approach involved giving amino acid drinks to two groups of volunteers in order to manipulate blood concentrations of the amino acid tryptophan, which is a vital ingredient in the synthesis of serotonin. One group received drinks that contained tryptophan. The other group received drinks that did not contain tryptophan. They were then asked to make judgments about sets of photographs of couples. Differences in the judgments made by the two groups reflected changes in their serotonin activity. [...]

The results raise the possibility that lower serotonin activity in people with depression and other psychiatric conditions could contribute to changes in the way they perceive personal relationships, or even in their ability to maintain positive personal relationships.

“Although this is only a small study, the same patterns may well extend to the way we perceive our own relationships,” said Professor Rogers. (via.)


Lady Gaga was a Geneticist: Why “Born this Way” Accurately Interprets the Biology of Homosexuality


Intro:
It doesn’t matter if you love him, or capital H-I-M
Just put your paws up
‘Cause you were born this way, baby

Test tubes with DNA and canvases with brushstrokes. Einstein and Shakespeare. Science and humanities. These two cultures have been polarized throughout most of history, benefiting little, if anything, from each other.

Though seemingly opposite in their methods, the sciences and humanities can have a symbiotic relationship in which one re-frames questions for the other to answer. Such a process is what biologist E.O. Wilson calls consilience, which can give rise to what scientist-turned-novelist C.P. Snow termed the Third Culture. In this recently bourgeoning Culture, scientists and artists are no longer separated by each other’s jargon and proposed models of the world. They are not mutually incomprehensible. This post is in the spirit of Jonah Lehrer, who’s book Proust Was a Neuroscientist draws wonderful parallels between, say, the novelist Marcel Proust and what his work inadvertently reveals about the nature of memory; or, for example, Paul Cezanne’s art and what it reveals about how our visual system works. It is an attempt to build but one bridge between science and modern art.

Modern art can be seen as a backdrop for hanging and interpreting scientific findings. What Lehrer argues is that, often, art elegantly intuits a finding in neuroscience — or, put another way, neuroscientsts often rediscover what art revealed decades ago. This post, though, switches the roles of discoverer and re-discoverer: In her controversial new single “Born this Way,” Lady Gaga has in fact re-discovered what genetics have taught us for the past 20-or-so years about the nature of homosexuality. She begins,

Verse:
My mama told me when I was young
We are all born superstars
She rolled my hair and put my lipstick on
In the glass of her boudoir
“There’s nothin wrong with lovin who you are”
She said, “’cause he made you perfect, babe”

Let us make one evidence-driven interpretation: from a scientist’s perspective, “He” and “God” must refer to evolution. It is the known process that got us all here; it is neither prejudice nor random. That aside, we are all born Homo Superstarius — as men or women with specific sexual proclivities that greatly reflect our exquisite biology. The fact that you consist of 100 billion human brain cells by default makes you a superstar in the animal kingdom.

That said, the biology of homosexuality involves an interplay of genes, hormones, brain structures, and everything external to these — what people mean when they refer to “environmental” influences. Of course, it also gets a substantial amount of media coverage (exhibit AB, and, oh boy, C) and is the source of much political tension.

So how much of our sexual preferences are the product of genes, environments, or both? Twin studies provide striking windows into the influences that genes have on our sexual orientation, on why we’re born this way and not that way. One study of twins found  that concordance rates with homosexuality were 52% for genetically identical (monozygotic) brothers and 22% for fraternal (dizygotic) brothers. A bit of subtraction here, and a wave of the mathematical wand there, and one sees about a 30% influence of genes on homosexuality. Additionally, and more specifically, the oft-cited gene Xq28 on the X chromosome shows significantly similar markers (small gene sequences used to identify cells) across gay men relative to heterosexual men. From birth, we are on the right and equal track, gay or straight. Said another way:

Chorus:
I’m beautiful in my way
‘Cause God makes no mistakes
I’m on the right track baby
I was born this way

Yet many people don’t see this as a type of beauty within and about each individual. To them, if you’re not heterosexual, then you’re not on the right track, and hiding in regret is the least you could do. First, Gaga’s response:

Chorus:
Don’t hide yourself in regret
Just love yourself and you’re set
I’m on the right track baby
I was born this way

Over at the hyperconservative forum Free Republic, one writer cites a study claiming that there is no genetic basis for homosexuality. The beauty of it all is that, well, I went back and read the study they referred to, and if you continue reading the Free Republic’s cherry-picked quote, it continues by immediately admitting that both genes and environment play profound roles; they do not discount genetic influences for one second, because to do so is to willingly entertain a delusion.

Inevitably, we get comments like these: “They aren’t born that way. But the majority of them are introduced to [homosexial] behavior when they are still young, effectively rewiring their emotional/physical connections. That’s why homosexuality is like a cancer. One cell infects others, which in turn infects others.” Note the use of neurobabble — using terms like “rewiring” and “emotional/physical connections” to mask an empty point with seemingly eye-catching jargon.

When it comes to reality, we are all entitled to our own opinions, but not to our own facts. It’s one thing to be misguided; it’s another to be immune to reason, and to spread that immunity — like a cancer – Free Republic style. Speaking of art, it’s not surprising that this kind of folly motivated the spanish painter Francisco Goya to etch his masterpiece, “The sleep of Reason Produces Monsters,” only today’s Monsters are people who denigrate homosexuality and refuse to consult the overwhelming amount of scientific data.

What’s more, much evidence exists that lends credence to the idea that hetero- and homosexual men are wired slightly differently at the level of brain structures — termed dimorphisms. One brain region, the hypothalamus, has been shown to be important in the production and regulation of all sorts of hormones. It also differs in size between men and women, and strikingly, between homosexual and heterosexual men. This was the first finding to suggest that homosexually has strong, measurable, neurological substrates.

More insightful correlations abound. With each son born, the odds of the youngest being gay increases by 33%. One intriguing explanation is that a male fetus induces a maternal immune response that becomes progressively more substantial with each subsequent male fetus. The original fetus produces antigens — molecules which are foreign to the mother — which have been proposed to be involved in sexual differentiation. The mother, in turn, produces antibodies in response to the male antigen. Subsequent male fetuses are exposed to the mother’s antibodies, which may down-regulate the “masculinization” of various brain regions. Rightfully so, this is still a topic of considerable research. Regardless:

Verse:
Give yourself prudence
And love your friends
Subway kid, rejoice your truth
In the religion of the insecure
I must be myself, respect my youth
A different lover is not a sin

To some, having an anything-but-heterosexual lover is a sin. The southern baptist Jerry Falwell pointed to homosexuals as the cause of God’s wrath on 9/11. Too, the naive and and misinformed fluff is in abundance. Hopeless hapless kooks over at the hyper-religiously-motivated True Origins summarize a lot of the twin studies’ data, and then embarrass themselves with bush-league counter-analyses that only reveal how little they know about what the terms “science” and “genes” mean.

Yes, homosexuality in identical twins has a concordance rate of 52%, not 100%, despite their having identical genes. A quick lesson in molecular biology will drive a crucial point home. Every cell in your body has the exact_same_genome. Every cell has the same 23 pairs of chromosomes, one from momma and one from daddy. And yet, brain cells and kidney cells and muscle cells have such striking differences in terms of structure and function.

How can this be? Analogously, how can one identical twin be gay and not the other, given that they have the exact same genomes? Answer: Because it’s the profile of active vs. repressed genes, which are regulated exquisitely and uniquely across cell types, that truly differentiates twins. Same DNA, but born this way, Gaga reminds us. Oh, and LOLz, the True Origins writers have PhD’s too. Trained at NYU’s prestigious Tisch School of the Arts, the point goes to Lady Gaga.

Many people, then, would call homosexually a “biological error.” But as the psychologist Steven Pinker notes,

What is evolutionarily adaptive and what is morally justifiable have little to do with each other. Many laudable activities – being faithful to one’s spouse, turning the other cheek, treating every child as precious, loving thy neighbor as thyself – are ‘biological errors’ and are rare or unknown in the natural world… regardless of where homosexuality resides in the brain, the ethics of homosexuality is a no-brainer: what consenting adults do in private is nobody’s business but their own. And the deterrents to research on homosexuality leave us in ignorance of one of the most fascinating sources of human diversity.

A study from last year drives the point home in its opening lines, which Lady Gaga summarizes for us in uplifting iambic octameter:

Bridge:
Don’t be a drag, just be a queen
Whether you’re broke or evergreen
You’re black, white, beige, chola descent
You’re lebanese, you’re orient
Whether life’s disabilities
Left you outcast, bullied, or teased
Rejoice and love yourself today
‘Cause baby you were born this way

If you’re a brown-eyed person, you cannot will yourself to have blue eyes. Our biological constituents have made that “choice” for us already; it is not a disability, it just is. Our prerogative is to rejoice in this truth. The same is true for sexual orientation; it just happens to be a human phenotype that is not displayed for all to see like eye color. There ain’t no other way, baby you were born this way. People like Bill O’Reilly simply don’t see the eye color properties of falling in love with the same sex. Gaga’s victory speech continues:

No matter gay, straight, or bi,
Lesbian, transgendered life
I’m on the right track baby
I was born to survive

What she said.

A very important question remains. How do “gay genes” continue in the gene pool? In other words, why are they not selected against, given that homosexual couples have significantly fewer offspring than heterosexual couples? There are three possible explanation, all with varying degrees of evidential support, and all of which can be found in a reader-friendly format here.

One is that if a male homozygous for “gay genes” has female relatives in whom the genes are heterozygous, and this heterozygosity confers a reproductive advantage, then the gene will be carried to the next generation in spades. Such a high-impact finding was, well, found, and even was reviewed nicely by Science magazine.  Evidence for this theory is now in abundance, too. Other similar models exist, and all are in agreement that there are genetic underpinnings for homosexuality.

The same is true for females, in this case female mice, in whom alteration of a single gene lead to pronounced male-like sexual behavior (a reader-friendly summary can be found here.) Ditto for flies(with a summary of the landmark paper here.) Indeed, Larry’s daughter in Chuck and Larry had it right when she listed a dozen animals in the wild that display homosexual behavior.

A second theory posits that males who are heterozygous for “gay genes” may indeed have higher success in attracting females or their sperm may have a competitive advantage, though evidence for this is still sparse but forthcoming. Thirdly, and most controversial, is the idea of homosexual kin selection, or that homosexuals help their own family members in ways that increase the fitness of relatives. This, therefore, increases the probability that a gay allele is passed on to the next generation.

Of course, these three theories are not mutually exclusive, and it is likely that they work in concert to propagate any “gay genes.” The point is that evolution isn’t just about one gene giving rise to one trait that is selected against or promoted; it’s about a balance and counterbalance, the costs and benefits, of the various traits to which genes give rise and that natural selection acts on collectively. It is a dynamic process. More intuitively, just think about how many sexual acts don’t result in conception, yet we still do them. They’re what give meaning to the word “pleasure” and were never selected against. Rounding the bases doesn’t mean you’ve hit a home run, but people still do it.

No matter black, white or beige
Chola or orient made
I’m on the right track baby
I was born to be brave

All in all, Lady Gaga recapitulates what genetics first discovered: you were born to survive, born to be brave, regardless of your ethnic background or sexual preference. It is no mistake to be born a particular race with a particular affinity for members of the same sex. And by making that point sprint home with iambic feet, Lady Gaga ushers in an insightful, biologically-friendly, and much-deserved anthem for the LGBT community, which happens to summarize two decade’s worth of genetics research.

Indeed, there’s nothing wrong with loving who you are, so put your ancestral paws up, because we all have the same DNA — we were born this way.

Visit Steve’s blog at www.okaysteve.com for other posts related to brain science.


Thirst Reduces Stress Response: “The Watering Hole Effect”


Assuming this is conserved in humans, the following passage might suggest that it’s better that you walk into an interview a little bit thirsty:

“We’re calling this the Watering Hole Effect,” says Eric Krause, PhD, a research assistant professor in the basic science division of UC’s department of psychiatry and behavioral neuroscience and first author of the study. “When you’re thirsty, you have to overcome some amount of fear and anxiety to approach a communal water source. And you want to facilitate those interactions—that way everyone can get to the water source.”

Krause and his team dehydrated laboratory rats by giving them sodium chloride, then exposed them to stress. Compared with a control group, the rats that received the sodium chloride secreted fewer stress hormones and also displayed a reduced cardiovascular response to stress.

“Their blood pressure and heart rate did not go up as much in response to stress as the control group’s, and they returned to resting levels more quickly,” says Krause.

“Also, in a social interaction paradigm with two rats interacting, we found them to be more interactive and less socially anxious.”

Further research, through examination of brain and blood samples from the rats, showed that the same hormones that act on kidneys to compensate for dehydration also act on the brain to regulate responsiveness to stressors and social anxiety.

The elevated sodium level, known as hypernatremia, limited stress responses by suppressing the release of the pro-stress hormone angiotensin II. Conversely, it increased the activity of oxytocin, an anti-stress hormone. (via.)

Thanks to hugthemonkey for pointing this one out on Twitter. Susan also posted a link to this interesting gem recently: A study led by Jillian O’Connor, a graduate student in the Department of Psychology, Neuroscience & Behaviour at McMaster University, found that people think they can predict whether a mate will cheat by listening to tone of voice.


Stroke damage control with caffeinol (caffeine and alcohol/ethanol)


A study found a special cocktail of caffeine and ethanol actually reduced brain damage in a rat model of ischemic stroke up to 80% so long as it was administered within three hours of the stroke. Now the study is being run on humans, check it out:

In experimental drug delivering the potency of two cups of strong coffee and a mixed drink has been shown to limit stroke-induced brain damage in animals. Now, this agent has been demonstrated to be safe in a small pilot study of ischemic stroke patients reported in today’s rapid access issue of Stroke: Journal of the American Heart Association. [...]

Those studies “demonstrated that the combination of caffeine and ethanol may reduce the amount of damage after stroke. Neither caffeine or alcohol offered protection alone, but the combination was protective,” says senior author James C. Grotta, M.D., professor of neurology and director of the stroke program, University of Texas-Houston Medical School, Houston, Texas. [...]

Researchers administered the combination to 23 stroke patients (16 women, average age 71). The patients represented a diverse racial mix: nine white, nine black, four Hispanic and one Asian.

“Our goal was to see if we could safely achieve the same blood levels of caffeinol that we achieved in our animal studies,” he says. “We discovered that we could use even lower doses than we used in the animal studies and achieve the blood levels that were neuroprotective in animals.”

Moreover caffeinol, which is given by infusion, can be safely administered to patients who are also receiving clot-busting treatment with tissue plasminogen activator (tPA). Eight patients received both caffeinol and tPA. One patient with a very severe stroke who received caffeinol and tPA suffered an intracerebral hemorrhage (bleeding within the brain), but Grotta says an independent safety officer concluded it was not related to caffeinol.

The first set of four patients were given low-dose caffeinol (caffeine 6 milligrams per kilogram plus ethanol 0.2 grams per kilogram). That dose did not achieve the target blood level, so the dose was increased (8 mg/kg caffeine and 0.4 g/kg ethanol) in the next group of 19 patients. That achieved target blood levels, he says. However, Grotta cautioned that the ethanol level may need further adjustment because a patient with a history of heart disease developed reversible heart failure at that dose level. It is unclear how caffeinol works to protect the brain, but it is being studied. (via.)

So they haven’t worked out all the kinks just yet, but all-in-all it sounds like they’re on the path to some good things there.