Genetics or environment

DR CHRISTINE JASONI
How something actually forms, even with things like wiring, is going to be an interplay between the genetics and the environment. And we know this because even if you look at twins – so genetically completely identical individuals – will have slight differences in their wiring.

You can take that back a step and say, well, there is no time during the development of the organism where their environment is absolutely identical. So in a way, you can’t do the experiment. You can say they are identical genetically, but even in the womb, they are in different environments. One is going to be on top of the other, so already, from very, very early on, their environments are completely different.

There are a lot of things that potentially could disrupt brain development. Where we start is with things that we can easily identify. Maternal nutrition is a good example – you know, if the mother is over or under weight, if the mother is under stress, if the mother is diabetic – all of these things could potentially affect the development. Not just the brain development, but the development full stop of the foetus.

So we have a genetic blueprint that defines sort of the basics of how the brain is built, and then upon that genetic blueprint are environmental influences. I think it’s important to point out that one of the things that we are actually just starting to discover is that the environment can actually be affecting the genes themselves.

So there is this phenomenon called epigenetics where you can have the environment influencing the genetic material itself, and so you do have cells whose genetics or genome is changing as a consequence of an interaction with the environment. So it’s almost like you have all three. You’ve got genetics hard-wiring, you’ve got the environment, just by exposure to different things, causing variability, and then you have the environment causing variability through interacting with the genome.

Acknowledgement:
123rf
iStockphoto