Rewiring the Brain
REWIRING THE BRAIN: HOW THE NERVOUS SYSTEM HEALS ITSELF by Lucas Angles / art by Yuchen Wang
Y
ou wake up one morning and immediately feel that something is off. As you grab a shirt and a pair of pants off the floor, you realize you can somehow put your shirt on with your right hand and your pants on with your left. You decide to further test your newfound ability; after making a pot of coffee, you discover that you’re fully capable of pouring the coffee with one hand while simultaneously reading a book with the other. This skill may sound like a superpower to most of us, but for those with “splitbrain,” or callosal syndrome, these experiences are common. In neurotypical individuals, the brain is separated into the left and right hemispheres. The two halves communicate through the corpus callosum, which can be thought of as a drawbridge, allowing each
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hemisphere of the brain to coordinate neural activity. This neural bridge consists of a network of connections spanning the midsection of the brain. Neural “checkpoints” carefully guard against unlawful travelers by monitoring for abnormal signals. However, in epileptic brains, these checkpoints are absent, allowing any neural signal to cross this bridge. Those with epilepsy experience seizures as a result of random signals traveling through the corpus callosum uninhibited. Logically, in one form of epilepsy treatment, surgeons sever the corpus callosum, effectively “raising the drawbridge” to stop any signals from getting across. This disconnection results in the “split-brain” phenomenon that gives the syndrome its name. As the two hemispheres can no longer communicate, the movement of a body part is not registered by the rest of the brain, causing half of the body to operate unconsciously. However, seizures may still persist after the corpus callosum has been severed. In this case, surgeons remove the regions where uncontrolled signaling originates. These procedures involve full or partial removal of the damaged brain region, the size of which can range from a fraction of a centimeter to an entire hemisphere [1].
GREY MATTERS JOURNAL AT VASSAR COLLEGE | ISSUE 2
