Electricity in living organisms was investigated for the first time towards the end of the 1700s at the beginning of modern science. This marked the beginning of understanding of the nature of the mysterious ''nervous fluid''. It was only in the 20th century that the electrochemical nature of the nerve impulses was attributed to the electrical activity of billions of nerve cells.
Nerves behave as small circuits that follow the same physical rules of electric circuits that run our appliances. Cell membranes of nerve cells have evolved the ability to keep separate electrically charged atoms called ''ions''. Batteries (Volta invented them) also keep electric charges separate, preventing the movement of charges. Thus nerve cells, muscle cells and heart muscle cells are mini batteries. To keep these batteries charged, living cells utilise the energy that is generated from the burning of fuel (food) with oxygen (just like in a combustion engine). This energy keeps the batteries charged.
When resting, cells remain charged, but when the circuit is open, a rapid, small current flows across the membrane. This triggers similar events in the adjacent bit of the same nerve cell membrane and it becomes a nerve impulse that spreads like a forest fire along the filament (called nerve fibre or axon). It carries this signal a long way, say from brain to any muscle. Nerve impulses last a few thousandths of a second and can travel tens of meters per second. Billions of nerve cells work together, driving complex activity from controlling walking, remembering an episode in life, recognising a face, imagining music or mathematics, talking, listening, or having feelings. There is nothing in our mental activities that is not based on this incredible electrochemical machinery.
Million of nerve cells work in synchrony, with tiny electrical signals (less that one 10th of a volt). These can be detected in the brain using electroencephalography, electrocardiography in the heart muscle, and electromyography in other muscles.
A telling analogy is to imagine a situation in which all 7.7 billion humans were to chit-chat on their mobiles at the same time. This gigantic complexity would be much less than the connections of the 100 billion neuron that goes on in our brains! No wonder the mere possibility of reading the mind is still far away.
Before we knew about electrochemical phenomena it was thought that the mind was made of other stuff - thinking stuff that does not belong to this world. Now we know that mind and spiritual life are complex but natural electrochemical phenomena.
The Fuzzy Logic Science Show is 11am Sundays on 2xx 98.3FM.
Send your questions to AskFuzzy@Zoho.com Twitter @FuzzyLogicSci Podcast FuzzyLogicOn2xx.Podbean.com
