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When we think about how the brain works—or how to fix it—we tend to think of neurotransmitters such as serotonin or dopamine. But the brain is an electric organ, its currency the impulses that fly across thousands of miles of neurons. As I describe in my new book, The Memory Thief and the Secrets Behind How We Remember: A Medical Mystery, more electrical activity is not always better. In fact, hyperactivity in the hippocampus—the brain’s memory center—is an early sign of Alzheimer’s disease that is gaining overdue interest as a therapeutic target.
Neurons come in two main “flavors,” excitatory and inhibitory. When an excitatory neuron receives enough input from other excitatory neurons, it fires, passing that signal along its axon to partners downstream. Inhibitory neurons usually tell other neurons not to fire. They are less plentiful than excitatory neurons but more diverse. In some ...
