Sunday 20 March 2022
The lectures for my MSc in neuroscience are all done now and I have a week before my final exams, then it's five months of project work that will take me up to the end of the academic year in August.
So, what have I learned?
I could drone on about a lot of tedious biochemistry, but let me take it up a couple of levels. At 30,000 feet, there are three remarkable things that stand out.
1. Life is miraculous
I'm a committed atheist, but having studied a bio science for a while, even I found myself questioning how life could possibly have evolved from random mutations and natural selection. Suddenly intelligent design didn't seem like such a crazy idea.
Living organisms are just so complicated and organic chemistry so astonishing, particularly the amazing functions that proteins can perform. The brain takes it up another notch. For example, the way that a series of complex chemical signals guides 86 billion cells to the right locations and tells them what functions to perform, during development of the human brain. Then the way each neuron, on average, connects to a thousand other neurons, some of which may be at the opposite end of the brain. The way neurons signal to each other via so-called action potentials and then chemical messengers called neurotransmitters, There aren't just one or two neurotransmitters, there are at least 40 (glutamate, serotonin, dopamine etc.), allowing much specific control of certain functions and, luckily for us, the development of drugs that can have targeted effects. The way chemical cargoes are literally walked to their destinations along microtubules by transporters - see the remarkable animation here. And so on.
It all just seems so improbable. But, on reflection, it clearly has evolved rather than been designed: Nobody would design it this way with so many layers of complexity. For instance, genetics is far more complicated than "DNA contains instructions to manufacture proteins": there are numerous "switches" that control when and how a gene gets expressed, and there is a lot of DNA whose function we simply don't understand. Nevertheless, it is nothing short of astonishing that it all works (most of the time).
One important feature of nature is the way that it has evolved natural defence mechanisms, including the immune system and processes like autophagy that clean up malfunctioning bits of cells. This has implications for things like Covid. Don't try to fight nature by trying to stop the spread of the virus - you will never succeed. Instead work with nature by developing vaccines which leverage the body's own defences.
2. All that it is to be human is just an accident
From a biological point of view, what sets humans apart from the rest of the animals is our highly developed cerebral cortex, and in particular the pre-frontal cortex at the front of the brain which enables us to develop strategies, plan and make decisions.
This, like all other areas of the brain, originally evolved to help us survive; to make us better hunter gatherers.
It turns out that our bigger brains allowed us to do other things when properly trained. But this is just an accident, a by-product of being smart enough to track a deer on the African savannah or built a shelter. Just think about this for a second. All the amazing things that the human race has achieved, all the science, technology, infrastructure, literature, art, sport, politics, philosophy, religion and all the things that influence our daily lives (living in houses, going to the supermarket, driving a car, reading and writing, listening to music, wearing clothing...) - all these things are just a side effect of having brains that allowed us to feed ourselves and protect ourselves from the elements a little better.
Everything around us, everything we have created, and all the damage we are doing to our planet as a result, is,effectively, just an accident.
3. We have a long way to go before we fix neurodegeneration.
Sorry to end on a negative, but what I have learned about neurodegeneration is that we have the corner pieces of the jigsaw in place, and maybe a few of the edge pieces, but, whether it's motor neuron disease, Alzheimer's, Parkinson's, Huntington's, or dementia with Lewy bodies, we are a long way from completing the picture. For virtually all neurodegenerative conditions we don't yet understand the underlying biochemical mechanisms, and we have yet to be successful in slowing or reversing the condition.
As I said to a couple of the other students, in their early twenties: "You could make a whole career out of this." Let's hope they do, and that, in the course of their careers, one of them makes a breakthrough.
