Ever wonder how nerves talk to each other? How are messages sent from your finger to your brain and back to your finger? Why does severing a nerve cause paralysis? What makes your pinky and ring finger feel tingly when you bump your funny bone? The answer to all these questions is a process called action potential.
Each time a nerve sends a message, two different ions rush in, and then out of the cell. This changes the voltage in the cell, and then cool things happen. Vesicles waiting at the end of the neuron fuse to the cell membrane, neurotransmitters are released, muscles contract, and heavy things are lifted. Your brain is made out of billions of neurons and they communicate via action potential, helping you move, speak, understand your surroundings, and feel emotions.
Groucho Marx once said that “life is a whim of several billion cells to be you for a while”. What he forgot to add was that some of those cells drive the boat (you) and others merely follow along. One of the downsides to being multicellular* is that there has to be a way to wrangle all these billions of cells and get them to work together. Very quickly, primitive nervous systems evolved, such as the nerve net in a hydra. After a few hundred million years, warm-blooded critters with giant brains roam the earth and the oceans.
The neuron was one of the first pieces of jewelry we ever sold and it continues to be one of the most popular ones. Does that really surprise you? What group of cells do you think is reading this email right now? What group of cells coordinated the muscles in your hand to help you click on the link for the neuron necklace? Basically, your neurons wanted to adorn the other cells it manages with jewelry of itself.
*Multicellular animals. Plants don’t have nerve cells but their cells can still create action potential.
