Coffee delivers jolt deep in the brain
Caffeine strengthens electrical signals in rats’ hippocampus
Most caffeine addicts would tell you that coffee sharpens the mind. It turns out that in rodents, a single dose of caffeine does indeed strengthen brain cell connections in an underappreciated part of the brain, scientists report online November 20 in Nature Neuroscience.
A clearer idea of caffeine’s effect on the brain could allow scientists to take advantage of its stimulating effects and perhaps even alleviate some symptoms of brain disorders. “Caffeine is something people are very interested in,” says neuroscientist Susan Masino of Trinity College in Hartford, Conn., who was not involved in the study.
So far, most of caffeine’s effects have been illuminated by studies using doses much higher than an average person’s morning cup of joe, says study coauthor Serena Dudek of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C.
Dudek and her team looked at the effects of smaller hits of caffeine on a small part of the hippocampus. In humans, this seahorse-shaped structure is buried deep in the brain behind the ears. After feeding rats the equivalent of two human cups of coffee (two milligrams of caffeine per kilogram of body weight), the team measured the strength of nerve cells’ electrical messages in slices of brain tissue. Nerve cells in this particular nook — a brain region called CA2 — got a major jolt from caffeine, showing a bigger burst of electrical activity when researchers stimulated the cells. Nerve cells in a neighboring part of the hippocampus didn’t show this sensitivity.