Shattered Nerves: How Science Is Solving Modern Medicine's Most Perplexing Problem

2 The Body Electric

∑ 2 The Body Electric In the mid-1700s, electricity was a novelty, its awesome power having been harnessed in a crude way a century earlier—when the static electricity generator was invented—with little improvement in the interim. And without batteries, only small amounts of electricity could be stored for short periods of time in a Leyden jar. One of the primary uses of electricity was to entertain the upper crust during parlor games at which people would be literally shocked or illuminated. Yet some scientists were also at work trying to understand and harness this strange force for the good of mankind. Among them was Benjamin Franklin, who was respected worldwide as a scientist as well as a founder and representative of an upstart nation. In fact, Franklin used a Leyden jar in his famous kite experiment in 1752, when he proved that lightning is electric by flying a silk kite tethered by a wet string through a cloud. A metal key was attached to the string, which led to a Leyden jar in which Franklin successfully bottled an electric charge. This led to his invention of the lightning rod, the purpose of which was to prevent fires by attracting lightning away from buildings and sending the charge into the ground. Some fundamentalists of the day were quite incensed at this invention. They thought that if God wanted to unleash fearsome lightning to burn down a building, who were mere mortals to interfere with his design? Franklin was also one of the first scientists to try to use electricity to return movement to individuals who were paralyzed. He even thought he might be able to cure paralysis by applying electricity to the skin, but he The Body Electric 29 learned that while he was able to induce uncoordinated movements, a cure or even coordinated control was out of the question. Franklin may well have contemplated the idea of creating functional movement in paralyzed individuals , but one of the great limitations he confronted was that his static electricity–generating machine and the Leyden jar he used in his experiments were not portable. Though he gave up his search for a cure when he realized that the shocks had no long-term beneficial e√ects, his interest in electricity and the study of the relationship between electricity and living organisms continued to thrive. Now, hundreds of years later, we take electricity for granted, except when it isn’t there, as when a storm knocks out power lines. It is then—when we start to wonder if the food in the refrigerator will spoil, and how we will make it through the day without lights, air conditioning, elevators, the ability to cook on electric ranges, and without tra≈c signals—that we begin to appreciate how electricity has become an integral part of our lives. But it is, in fact, much more essential to our being than we realize, for our bodies are electrochemical machines. The acts of settling into a chair, opening this book, and reading these words, require the firing of billions of nerve cells, called neurons, in your brain and throughout your body. At this very moment, as you see, absorb, and think about what you are reading, cells within various parts of your brain are firing o√ tiny jolts of electricity that send signals to neighboring neurons that together enable you to see and comprehend the symbols on the page and to contemplate their meaning. Visually processing the words is accomplished primarily by the neurons in your visual cortex in the back of your brain. As you prepare to turn a page, another set of nerve cells in your motor cortex, located in the middle of your head, send o√ action potentials, which are transmitted along nerves running down your spine to your arm and hand, where the electricity causes the muscles to contract. While this massive amount of electrical activity is going on within your body, without so much as a conscious thought, you turn the page. The process that enables you to do all of this involves chemical responses as well. When an electrical signal reaches the end of a neuron, it triggers a reaction that releases chemicals, called neurotransmitters, that 30 Shattered Nerves travel across the tiny gaps between the mass of neurons that make up your brain. After leaping across these gaps, or synapses, the neurotransmitters attach to nearby neurons and instruct...