behavior · Epigenetics · Genetics · Medicine · neuroscience · the brain

Epigenetics and Behaviour: Part 1

A Serendipitous Discovery

I remember the first time I learned about epigenetics. It was during my undergraduate degree in Molecular Genetics. However, I did not learn about it from lecture, but rather while watching an episode of NOVA, a PBS documentary program that focuses on science.

They were talking about a study that discovered a link between a population of people in Ireland who had an increased prevalence of Type II diabetes, high blood pressure and obesity. The Irish potato famine occurred in the 1800s and saw a blithe attack a main food source – potato crops. Here’s a link that discusses the potato famine in more detail –  Irish potato famine. The descendants of women who lived through the potato famine gave way to grandchildren who made up that group of people with a higher prevalence of Type II diabetes, high blood pressure and obesity.

How could this be? The group with the higher prevalence of those conditions listed had come from grandmothers who survived the potato famine. The medical conditions seemed to skip a generation. There was no known mechanism that could account for this occurrence. It seemed to fly in the face of the central dogma and the current understanding of evolution. The central dogma states that DNA is transcribed into RNA and then translated into protein. Our understanding of evolution was survival of the fittest – that those who survived to reproduce would have their genome passed on to their offspring.

So what happened? The researchers surmised an incredible and complex mechanism that explained how these conditions had somehow skipped a generation. It goes like this.

Environmental Exposure and Epigenetics

It all starts with a women who is pregnant. The embryo is female. Women are born with all of their ova or eggs developed. These eggs will be released, one by one, at puberty and the onset of the menstrual cycle, for the rest of the woman’s reproductive years . Men, on the other hand, are not born with their full complement of gametes or sperm. For men, their sperm is produced basically on demand at the onset of puberty.

So, the female fetuses’ eggs are being developed in utero. The woman carrying the fetus is exposed to environmental factors (in this case famine) which results in changes to the DNA of the embryo, including the DNA found in the eggs of the developing fetus.

What changes occur in the DNA of the fetus and her developing ova or eggs? The DNA of both the fetus and her eggs is marked with chemicals (based on, in this case,  environmental factors) that determine what genes will be expressed and what genes will not be expressed.

The fetus is then born with her full complement of eggs. She reaches puberty and an egg is released at each menstrual cycle. One day, she becomes pregnant and gives birth to a baby. That baby grew from an egg that had been epigentically marked while in utero.

This is how the environmental factors a grandmother experiences can be passed on to not her children but her grandchildren’s genome. These genetic markings are termed the epigenome. The epigenome adds another layer of complexity to genetics and evolution. Next, I’ll discuss behavior and the epigenome.

Adderall · ADHD · Benzadrine · Evolution · Learning · Medicine · mental health · Nature · neuroscience · pomodoro · psychiatry · Psychosis · Ritalin · Science · Stimulants · the brain

Nature vs. New World: The Problem with Today’s Society

Being the go-getter that I am, I have been taking an online course through a fantastic online learning website by the name of Coursera. I hope one day to be involved in medical education and so I started with a course called Learning How to Learn. (Note: this is not a plug for the website – I just enjoy providing links to the things I discuss in my articles – Aside: I wish I was supported by ads, perhaps one day!!)

So, here I am, making my way through the course and learning both some valuable study techniques as well as the neuroscience behind how we learn. One of the learning techniques described is what is known as a pomodoro. In short, it is a way to break one’s learning into small, manageable chunks and then provide a small reward after each pomodoro. (I do enjoy this technique, it puts a damper on my tendency to reach for my cell phone or check that latest facebook post). Tonight, I happened to be pomodoro’ing my way through (I just made up a word there) the course whilst watching a Netflix documentary by the name of Take Your Pills

After each pomodoro, I allowed myself to watch a bit of the documentary as my reward. Well, how serendipitous indeed! Turns out my mind found a link between what I am learning on Coursera and what I am watching on television. (I love how the brain works so naturally when it comes to getting the creative juices flowing!)

Now, I am not here to write a review for either the course I am taking or the documentary I watched. Suffice it to say that they are things that I am both enjoying (I haven’t finished the course yet) and that I enjoyed (I did finish watching the documentary).

Humans have an innate ability to remember the details of say, a room we walk into, even days or weeks later. We built these natural spatial and visual memory abilities over eons of evolution. Quite rightly so, given that our day to day survival depended on remembering how to get back from a hunt, or where the best place to pick for berries was located.

The documentary Take Your Pills discusses pharmaceutical amphetamines (Adderall, Ritalin, dexedrine, Concerta and Vyvanse, to name most) and the increasing licit (and illicit) use by children and adults in Western society.

It gives an overview of the history of pharmaceutical amphetamines and states that the first article describing the abuse of benzadrine (a prescription drug otherwise known as amphetamine) amongst college students was in Time magazine in the 1930s.

It appears our society has had difficulty focusing on learning school subjects for a long time. Why might that be?

It’s simple. Our brains have been conditioned to learn spatially and visually through movement over hundreds of thousands of years – to survive for the short term, not the long term. 

Now stop and think about our children’s learning environments and subject matter. Math, science, english, social studies and more. And how are our children taught these subjects? By sitting in one desk, often in one classroom. Do these two environments and modes of learning jive? I think not.

And where is the short-term benefit? Do years of school provide any short-term benefit or reward? Well, yes, but only if you do well in school. What of the children who do not? Methinks some may end up requiring ADHD medications.

Now, I don’t want to vilify the use of these drugs in today’s world. I do believe they have a place, with judicious use.

We can draw the same analogies with the adult world and our working environments.

The question then becomes, is it us that suffers from a problem, or is it how our society is designed that causes our suffering? I’m betting on the 2nd option.

This is, no doubt, not a novel idea. But, it was a nice A-ha moment for me that I will take to the clinic, and perhaps beyond to the classroom. Our teaching and working conditions need to take advantage of that innate ability to function and learn based on our natural visual and spatial learning abilities. There are even parts of the brain dedicated to learning naturally and easily in this manner! How cool is that!

Thanks for reading, and I hope you learned a thing or two about learning and working in today’s world!

~ ThePinkLady