Child Neuropsychology

The world of genetics is moving so fast it is hard to keep up. Luckily one of my favorite writers on the subject Robert Plomin (together with Oliver Davies) has written an update on the genetics of child psychology and psychiatry in the Journal of Child Psychology and Psychiatry. There is a lot of information in the article regarding the latest genetic findings but the issue that stuck me most was about how our understanding about how genes work is changing. My understanding of genes was the classic model described succinctly by Plomin and Oliver as “a gene is a sequence of DNA that is transcibed into messenger RNA which is then translated into amino acid sequences, the building block of protein”. The proteins then build to form brain structure, neurotransmitters etc.

The hunt has been on to find the genes that affect behavior and illness using this classic DNA process. There have been successes with a number of single gene neurological disorders identified such as Huntington’s Chorea and PKU. For these conditions the gene has been located and the sequence from gene to protein to behavior is well documented. Unfortunately this process has not worked in discovering the genes for most other psychological/ psychiatric disorders or for behavior in general. Although it is clear that there is a substantial genetic component in behaviors such as IQ, reading and language and disorders such as ADHD and Autism, as shown by twin studies, the actual genes responsible have not been found. Recent arguments have focused on the idea that many genes may be involved in combination to influence such behaviors. Plomin’s article however also raises another difficult issue. There may also be a problem with the standard DNA model as an explanation for gene- behavior effects. There are a number of puzzles regarding the standard coding DNA model. Firstly there are far fewer of these traditional genes than expected (about 24,000 in humans). Also they only make up about 2% of DNA, the other 98% were said to be junk, a byproduct of evolution. Another factor is how little these traditional genes vary between individuals and species for example simple worm like creatures called called nematodes have 19000 genes compared to the 24000 in humans. Are we not that much different to nematodes? Chimpanzees share 99.4% of DNA coding genes with humans.

Plomin and Oliver show that part of the problem may be that we have not focused on the way that RNA works. Out of the 98% thought to be junk DNA about 1/2 does produce RNA but not the type of RNA that codes for amnio acids. Instead the non coding RNA ‘plays an important role in regulating the expression of the protein coding DNA‘. RNA is also much more complicated than once thought and many different types of RNA have now been identified, including microRNA, tRNA, snRNA, rasiRNA, snoRNA, etc. How RNA works is explained in detail in the article but that explanation is too detailed to describe here other than to say that there is much more variation between individuals and species in terms of their RNA profile and that it is the RNA that may hold the key to understanding more complex gene behavior effects. The implication of these findings according to Plomin and Oliver is that we should be analyzing the whole genomes of individuals rather than searching for individual genes. This is becoming cheaper and easier to do but so far the results are still very limited.

My take home message from the article was that genes and their effects are not as simple as most people believe and as much of the media describes. It is very unlikely that we will find the gene for Autism, for IQ or for being gay. Instead such behavior is likely to be the result of a complex interaction of many different genes, with different types of RNA dictating how the genes are expressed which in turn will probably be influenced by factors in the environment. Hugh discoveries are being made all the time but I think the more that is known the more complex it all seems.

A new study on the benefits of stem cell therapy in patients with multiple sclerosis is a very exciting one for all neuroscience. The study shows that by giving stem cells to MS patients, disability is halted or reversed. The study included measures of neuropsychological function as well as neurological rating scales and quality of life. Improvements in these areas were seen in 17 out of 21 patients and there was no deterioration in the other 4. The reason why it is so important lies in the use of stem cells. The problem with all neurological disability including childhood brain injury is that the brain can not repair itself. This is to do with the way the brain develops. The brain starts to develop at 40 days old with stem cells lining the neural tube. The stem cells turn into precursor cells, then blast cells and then specialized neurological cells. The whole process lasts until the fetus is approximately 6 months old. It is an amazing process with cells developing at the rapid rate of approximately 250,000 a minutes. However, by the end of six months the process stops and you are left with the brain that will last you the rest of your life. If you damage the cells in your brain they will not grow back in the same ways as skin and bone cells would. This is the reason why neurological injury is so hard to treat. If, however, we can replicate the natural development process by using stem cells the possibility is there to treat all neurological disability. It is still early days in terms of this research but these findings are very encouraging. A major problem has been that you basically need to use embryos to produce the stem cells. The recent Bush government in the US was against this on religious and moral grounds. There are however, some new discoveries now in using adult stem cells from different areas of the body. Also it is believed that Barak Obama will allow the stem cell research to start again. Just recently the FDA in the US approved use of stem cells in human medical trials for spinal chord injury. If the research does take off and if these early research findings are replicated there is the very exciting prospect of new treatments for neurological disability in the future.

A recently study from the University of California, Berkeley found differences in brain activation between children from low and high socioeconomic status (‘rich and poor kids’). The researchers used EEG to measure activation in the pre frontal cortex and found children from low socioeconomic backgrounds had a low EEG response which was similar to children with brain injury. The psychology group at Berkeley have a distinguished history of research looking at the development of pre frontal cortex. One of the key findings over the last 20 years is the role that the environment has in brain development. Originally work undertaken on rats showed that those in a drab environment had less well developed brains than those living in stimulating environments. It is likely that poor children have less stimulating environments which in turn affects their brain development. Some of my clinical work is with children who have been abused and neglected and a consistent finding is that they have lower than average intellectual functioning and low academic achievement. This latest study adds to the growing body of research highlighting the importance of early intervention for good brain development.

I have just developed a new concept combining my knowledge of neuropsychology with computer games. It is called Neurogames and the games are available for purchase on my new website neurogames.co.uk. At present I have developed four games helping children to develop maths and numeracy. The games are based on the science of the development of reading and numeracy drawing on some of the work from the contributors writing in our book Child Neuropsychology as well as some of the research studies highlighted in this blog. The games take a developmental course mirroring the normal developmental sequence of reading and maths acquisition. The games also draw on my clinical expertise in terms of what helps children with neurodevelopmental difficulties. This includes errorless learning, frequent extrinsic rewards, visual based learning with bright attractive graphics and short game sequences with clear indicators to help children with short attention span. Computer games are also not critical and therefore the social pressure on learning is eliminated. Finally games are fun and Neurogames provides a new fun way of learning. I hope that the games will be helpful for children who find learning difficult whether it be because of a specific difficulty such as dyslexia or dyscalculia or because of a general difficulty such as ADHD, learning disability or brain injury. The games are easily to download and can be purchsed direct from the site. I also hope over the next year to develop more games to help with language and memory development. Let me know what you think.

How much do you know about the brain and how it works? I have found an interesting website from the Society of Neuroscience that presents the core concepts that everyone should know about the brain and the nervous system. It is particularly aimed at teachers and links with the curriculum in the US. The website provides a good guide to several aspects of neuroscience and is worth a look for parents and professionals.
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One of the major problems with the internet is wading through the junk and knowing whether what you are reading is correct and valid. In terms of knowledge about neuroscience I would recommend the website Neuroscience for Kids. Although it is aimed at kids it is not simplistic and much of the information is also a useful lay guide to neuroscience for adults. It can also be informative for children especially if they have any injury or illness connected to the brain. I think that this site is an excellent resource and shows the internet at it’s best.