The hormone has also previously been linked to higher aggression levels and researchers wanted to find out whether oxytocin also reinforce negative social sentiments.

56 Participants were asked to inhale oxytocin but half were given a placebo.  They were then asked to play a game with another competitor, who was without the knowledge of the participant a computer.  In the game participants were asked to choose one of three doors and was awarded a sum of money that was hidden behind the door.  Money awarded were sometimes more and other times less, creating conditions for gloating and envy.

The study was then performed again but the placebo was given to the other group that received oxytocin in the first trial.

Researchers found that when oxytocin was inhaled, levels of envy and gloating displayed were higher when more or less money was won than the other player.  Dr Simone Shamay Tsoory who conducted the experiment said, “Subsequent to these findings, we assume that the hormone is an overall trigger for social sentiments:  when the person’s association is positive, oxytocin bolsters pro-social behaviours; when the association is negative, the hormone increases negative sentiments.”

Oxytocin is considered as treatment for Autism, “The results of the present study show that the hormone’s undesirable effects on behavior must be examined before moving ahead.” said Dr Shamay-Tsoory.

http://wwwsciencedaily.com/releases/2009/11/091112095038.htm

Researchers at Duke University Medical Center found epigenetic changes to genes (changes to the way genes are switched on and off and not to the DNA sequence itself) strongly linked to autism.

Co-lead author Simon G Gregory Ph.D assistant professor in the Duke Department of Medicine said “In both blood samples and brain tissue, the methylation status of specific nucleotides in the oxytocin receptor gene is significantly higher in someone with autism, about 70% compared to the control population, where it is about 40%.”

Oxyctocin plays an important role in social behavior.  In two preliminary studies oxytocin was used to decrease repetitive behavior and improve emotional interpretation in autistic children.

Dr Gregory said “These results provide a possible explanation on why social isolation forms part of the autism spectrum – because an autistic individual’s ability to respond to oxytocin may be limited.”

119 individuals with autism were examined for genetic mutations.  One had a DNA deletion in the OXTR gene (oxytocin receptor gene), examining this boy’s family members they found his brother also had autism but did not have the OXTR deletion.  The mother had symptoms of obsessive-compulsive disorder but not autism, “autism and OCD share the symptom on intensely repetitive thoughts and behaviors”.

Researchers then examined the boy with autism and without the DNA deletion and found the elevated methylation levels, (epigenetic mutation) in the OXTR receptor gene. Re-examining all the other independent blood samples they found consistent differences in OXTR methylation.

What I also find interesting is previous findings that Estrogen enhances the effects of oxytocin while testosterone mutes or blocks oxytocin.  We know that there is 4.1 ratio for boys with autism compared to girls and Dr Gregory above says that the epigenetic mutations limit an autistic individual’s ability to respond to oxytocin.  This makes it tempting to speculate that estrogen provide some protection for girls against autism.

http://www.sciencedaily.com/releases/2009/10/091021212247.htm

“There is a large body of scientific literature in humans that points the finger at PCB’s, linking them to neurodevelopmental problems we see in kids,” said Pamela Lein, lead author.

The first showed that low level exposure in utero and neonatal exposure alter the development of brain cells.  In fact low level exposure had more pronounced effects than a higher dosage.

“We think that one of the major reasons we have not seen effects in previous studies is that at higher doses PCB’s become toxic to cells and the brain has defense mechanisms to deal with disposing of these damaged cells,” said Pessah.  “Future studies of PCB’s and related compounds should be examined at lower doses more relevant to human exposures” he continued.

The second study showed that PCB’s affected brain-cell circuits in the hippocampus, an area in the brain known to be impaired in many neurodevelopmental disorders and behavioral disorders like autism, ADHD, learning disabilities, sensory deficits, developmental delays and mental retardation.

The third study describes the effect of PCB’s in detail on a molecular level.  They found that PCB’s lock the calcium channels in the brain in the open position, resulting in over-excitations on neural circuits.

Calcium channels are responsible for generating the signals needed for the extension and branching of dendrites.

PCB exposure, in utero and neonatal, alters dendritic plasticity.  Dendrites receive signals from other cells in the body, and changes shape in response to the signals they receive.  The study showed how this alteration in plasticity negatively affected learning.

Pamela Lein said, “Dendritic plasticity is important to how we process information and, when you perturb that, you interfere with complex behaviors like learning and memory.”

Examining the hippocampus, Pessah said he believes PCB’s lead to overgrowth of dendrites and inhibition of neonatal pruning that takes place during gestational development.  Brain cells exposed to PCB’s cannot respond to proper learning.

Explaining why some children go on to develop autism while others don’t, Pessah said, “We think that in autism, for example, at-risk children have deficient inhibitory circuits.  So, if you have a PCB that promotes the excitatory side of the circuit, they would be much more at risk of developing the disorder.”

The question for me now is why “at risk children” have deficient inhibitory circuits? Are there some other chemicals out there that can cause deficient inhibitory circuits, like for example cigarette smoke, and is it possible that certain nutrients, a hormone like vitamin D or overall a good nutrient rich diet can protect against this predisposition?

You can find more information on PCB’s here

http://www.sciencedaily.com/releases/2009/04/090413204546.htm

The latest and possibly one of the most startling studies on vitamin D, raise the question on whether Autism can be caused by a deficiency in vitamin D. A nutrient that many people in the northern hemisphere are deficient in for two reasons, the most obvious lack of sunshine and the second reason because they do not eat sardines or salmon, the only food that can provide you with sufficient amounts of vitamin D. The study from Sweden was on Somali immigrants that have an unusually high rate of Autism after several years of migrating from a country where autism is virtually nonexistent.

What I find frustrating is a study I read a few months ago, well after the emergence of vitamin D. The researchers fed participants oily fish and the authors contributed the good result to omega 3. There is more than one ingredient in a food, and what we need to consider is that it is more than just a possibility that these nutrients work together in harmony.

One of the reasons why supplements just cannot reproduce the same results as a food, proved in studies on lung cancer where, carrots have a protective effect but supplements with beta carotene increases the chance of developing lung cancer.

http://www.sciam.com/article.cfm?id=vitamin-d-and-autism

Researchers in Sweden made an accidental discovery finding that children who live in homes with vinyl floors are more likely to have autism. Vinyl floors can emit chemicals named phthalates, and what makes this so interesting is that phthalates are known to interfere with the production of testosterone. Phthalates are commonly used in a wide range of products like plastics, many others even food and most people including infants are exposed to phthalates through lotions and shampoos etc.<

An eight year study previously published also linked high levels of testosterone in the womb to autism, completing the circle of dots;

autism – vinyl floors – phthalates – testosterone – autism

The study associated four environmental factors with autism.
vinyl flooring,
maternal smoking
family economic problems
condensation on windows

The latter two factors have underlying issues such as studies finding that families with lower income are also more inclined to eat fast food, indicating nutritional issues and possibly food additives containing hormone disrupters.

The condensation on windows indicate poor ventilation in the house and most likely higher quantities of volatile gasses from flooring and other household chemicals, second/third hand smoke etc. are breathed in.

Most people see the environment as a weather problem, but as devastating a problem as rising sea levels and changing weather patterns are, what is being grossly overlooked is the anguish of health and mental problems our polluted environment is causing our children.

http://www.sciam.com/article.cfm?id=link-between-autism-and-vinyl”

The study confirmed that IQ was not affected, however even mild cases of autism can place a child at a disadvantage.