Brain collates electrochemical inputs from everywhere, processes and outputs to everywhere.
The brain is an extraordinarily complex organ which currently attracts huge amounts of research spend and we are closer now to knowing how it all fits together, than ever before.
Your brain has around 100 billion neurons, and each communicates with thousands of others – as many connections as in the world’s telephone system, the biggest machine on the planet. Neurons communicate with each other at special junctions where chemical reactions involving the transfer of electrical signals helps to bridge the gap between one neuron and the next.
Recently researchers at Bristol University in the UK, have discovered that the electrical signals that are initiated as a result of ‘sensory’ stimuli can degrade in older or damaged brains. These electrical signals, called action potentials, are triggered near the neurone’s cell body and once produced, travel rapidly through the massively branching structure of the nerve cell, along the way activating the synapses that the nerve cell makes with numerous other nerve cells to which it is connected.
This work has identified that the production of electrical signals is not only key to the proper functioning of the brain but that neuronal excitability, the ability of individual cells to generate brief but very large signals, which happens in pretty much all nerve cells, can be shown to vary.
It is changes to the activation properties of membrane proteins called sodium channels, which mediate the rapid upstroke of the action potential by allowing a flow of sodium ions into neurones, that has been shown to be a differentiator in brain performance.
However, recent work published by Oxford University scientists in the journal Current Biology, has shown that external electrical stimulation by passing small electrical currents through certain parts of the brain, can lead to increased cognitive performance. The process, called Transcranial Direct Current Stimulation (TDCS), can improve capability for up to 12 months with no apparent negative side effects.
This kind of research goes to a better understanding of how the brain works. Results showed that the treatment improved vision, decision making, problem-solving, mathematical, language, memory, and attention capabilities but that it was not a silver bullet – cognitive prowess still requires appropriate commitment and effort.
The big ethical question now is how to make portable devices, worth little more than £500, available to the general public such that TDCS is not used to exploit the vulnerable and enthusiastic.