Tag Archives: genes

Ever Wonder Why Humans Are So Clever? Scientists Hone In On Special Genes

brain clever gene

There is no doubt that humans are the smartest creatures on the planet. But for the longest time it has been unclear just how exactly we made the jump from simple creatures to ones capable of mathematics, ethical debate and invention.

But now scientists may have begun to unravel the mystery, discovering that three similar genes may be behind the boost.

Coding for the expansion of our brains by increasing the potential for creating neuronal cells, it may be that these three genes hold the key to human intelligence.

clever gene evolution notch2

Monkeys are intelligent creatures, and share most of our genetic material. So what makes us different? Image courtesy of Flickr.

Genes For ‘Clever’ Are A Mistake.

Publishing in CellPierre Vanderhaeghen and his team investigated the role of the NOTCH2NL gene.  This is just one of a family of genes responsible for modulating the development of organisms, but has appeared in four similar forms in humans.

By reconstructing the story of the gene over time, the team noticed something interesting.

Around 14 million years ago a part of the gene was copied by mistake, and remained silent for millions of years. Later another mutation and insertion rendered it functional, eventually leading to a total of four versions. Three work, and the last remains quiet within our DNA.

clever dna gene brain intelligence

Our DNA defines what and who we are, and by studying it we can learn more about what it is to be human. Image courtesy of Flickr.

So what does the gene do? Aside from promote brain cell maintenance, it seems the trio also increase the potential for new brain cells to be created. When Vanderhaeghen inserted the genes into a growth culture including human brain cells, they created new stem cells.

These stem cells can differentiate (change) into new brain cells.

Furthermore, a certain protein expressed by the gene stops further change, meaning that new neuronal cells can replicate over and over.

Basically, the duplication of the gene seems to lead to a greater number of brain cells, and with that, intelligence.

Neuronal Cells, Evolution and Cleverness

When studying ‘intelligence’ humans have made a lot of mistakes. First we considered a ‘larger’ brain likely ‘more intelligent’, but when you consider an elephant you can see this doesn’t quite work.

It seems that the two best predictors of intelligence are ‘surface area’ of the brain and ‘number of connections’ between the cells.

Basically, by increasing the surface area of the brain there is more room for brain cells, and by forming efficient and numerous connections between them these cells can work more effectively.

This is the case in the human brain, which due to its many rolls and crevices boasts a relatively huge surface area.

This new data sheds some light on why our brains may have developed this way, with the NOTCH2NL genes fundamental in both producing surplus neutrons and modulating their abilities.

But the odd thing is that this kind of  ‘mistake’ is fundamental to evolution.

gene clever brain

Every species on earth evolves, and millions of years of mutation and selection has created the wealth of diversity we see today. Image courtesy of Flickr.

When a species reproduces it passes its genes, the coding material for the production of the species, down the line. Although the mechanisms for replication of the molecule are pretty good, mistakes are made. These are called  ‘mutations‘.

Most are harmless, and have no clear effect on the new organism. But sometimes they confer some benefit, increasing the organisms, and thus  the species’, chance of reproducing again.

Explained in the context of evolution, these mutations  are defined as ‘individual variation‘, and this is one of the central tenets of evolutionary theory. In the case of the  NOTCH2NL gene, it seems the mutation means greater intelligence.

More research is needed to explain intelligence fully, but it seems we have caught a lucky break.

What’s Next?

The opinions expressed in this article are those of  Dr Janaway alone and may not represent those of his affiliates. Featured image courtesy of Pixabay.

Brain Ageing May Be Due To Genetic Problems. Study Shines Light On ‘Weakness’

As you grow older many things are certain. Things wear out. One issue is a loss of brain cells (neurons.)  Although the numbers lost through ageing aren’t as striking as they once were, we cannot ignore the fact that the nature of brain cells puts them at risk to damage by any means. And whats worse, losing them can have very significant effects on your life.  Previously, our complicated model of understanding explained the severity of brain disease based on a lack of cell replacement or ‘hardiness‘, amongst other factors such as increases in certain proteins. But new research may have found a fundamental problem with how our neuron’s use energy, and a genetic tendency toward self-destruction. It may be that the brain is programmed to burn itself out.

Old Brains and Old Genes

In a new study published in Cell Reports, researchers compared brain cells from both ‘young’ and ‘old’ donors. They compared the levels of genes ‘upregulated‘ (i.e more deliberately active,) in association with brain cell energy processes such as mitochondrial activity (a cell organelle involved in energy use. )’Upregulation’ of a gene means that the behaviour or process it codes for is more likely to happen, i.e up regulation of genes associated with growth means the organism grows more. They then looked at whether there was a difference in the brain cells susceptibility to damage dependent on the level of the genes expressed in each group. Simply put, they wanted to know if age effected the genetic activity governing brain energy use, and whether this was good or bad.

brain death neutron gene

Neurons, once lost, do not return. So why are they so delicate? Image courtesy of NICHD

They found that in older cells,  that 70% of  genes associated with energy use were expressed at lower levels. They also found that replicative processes associated with energy use, as well necessary protein creation, were also lower. Most strikingly, this was associated with defects in the very mitochondria affected. This means that since the brain relies on mitochondrial activity for energy, that damage to the brain may actually occur due to genetic issues rather than simply blood loss or other disease.  This will increase the risks associated with ageing, as well as potentially explain why the brain dies off as we grow older.

A New Model Of Brain Death

Although the research has provided a fundamental shift in how we may understand brain cell death, it must be placed in context. Rather than undermining current theories, such as neurons being especially susceptible to blood loss, it may both help to explain them and provide a better picture of how brain cells die overall. As maudlin as this may seem, it may provide new avenues for genetic therapy down the line. We are already seeing genetic therapies being developed that target ‘problematic processes.’ There is no immediate reason that these therapies could not be adapted after further research. So, in this case, knowledge is very much power.

So watch this space, because as we age the need for more intervention increases. And this may be another step toward protecting our brain, the centre of our being, for that much longer. And let us know what you think in the comments below.

What’s Next?

The opinions expressed in this article are those of  Dr Janaway alone and may not represent those of his affiliates. Images courtesy of flickr. The content matter of this article has been simplified greatly from the original journal publication. This has not been done to obscure or overly simplify  the findings of the research, but to make the findings communicable. And I don’t mean to just the lay person, I mean trained professionals who can’t make sense of ‘ We found that 70% of all mitochondrial genes were downregulated in old iNs compared to young iNs ( Interestingly, categorization of the mitochondrial genes into functional groups revealed that 93% of the genes that composed the mitochondrial ETC complexes I–V were downregulated in old iNs (example of source text. )But I am very aware that in the process of making the data and article more understandable that I risk making mistakes in my inferences. If that is indeed the case, please do let me know so I may retract and improve on the subject matter at hand. Ben.