There are something like 100 billion neurons in your brain – a literally mind boggling figure. Are you really able to imagine what a 100 billion of anything looks like?
As if that weren’t challenging enough, each neuron has up to 50,000 connections with other neurons, and each connection (a synapse) is an electro-chemical switch of a sort – passing information and energy across the gap between two neurons. This makes the total number of states of the brain (number of “on” or “off” neurons) a figure which is……well, unimaginably huge!
I was taught at university that a synapse was a pretty simple connection between two cells where on neuron released a chemical, which then crossed the gap and stimulated the next neuron. This, of course, is a huge oversimplification.
Researchers have recently managed to describe a single synapse much more accurately.
The new model shows, for the first time, that widely different numbers of proteins are needed for the different processes occurring in the synapse,” says Dr. Benjamin G. Wilhelm, first author of the publication. The new findings reveal: proteins involved in the release of messenger substances (neurotransmitters) from so called synaptic vesicles are present in up to 26,000 copies per synapse. Proteins involved in the opposite process, the recycling of synaptic vesicles, on the other hand, are present in only 1,000-4,000 copies per synapse. The most important insight the new model reveals, is however that the copy numbers of proteins involved in the same process scale to an astonishingly high degree. The building blocks of the cell are tightly coordinated to fit together in number, comparable to a highly efficient machinery. This is a very surprising finding and it remains entirely unclear how the cell manages to coordinate the copy numbers of proteins involved in the same process so closely.
It’s not just the numbers which are astonishing, its the complexity, and that last sentence particularly struck me – “it remains entirely unclear how the cell manages to coordinate the copy numbers of proteins involved in the same process so closely”
Just how much DO we know about how the human body works? How much DO we know about how it evolves to this level of complexity, both through an individual lifetime from the fertilisation of a single egg cell to a fully grown human being, and throughout history from single celled life forms to the multi celled human beings?
Humility. That’s what we need as scientists. Humility. Our ability to discover and understand is astonishing, but so far pales in comparison with the complexity of a single human being.