Science of the bloody brain
A brick had unforgivingly fallen on the back of it, smashing a section of his skull like a spoon knocking the shell off the top of a hard-boiled egg. And so, after surgery, part of the surface of his brain was left precariously unprotected except for a layer of skin. Peering through this accidental window into his head, Dr. Angelo Mosso was able to measure the pulsations of the brain’s blood supply. Cane sat in Mosso’s lab with pressure gauges strapped around his feet and a handmade instrument resting delicately on the skin over his vulnerable brain. This was to be the world première of neuroimaging.
“What is 27 times 13?” Mosso inquired. Cane thought deeply and silently while the various contraptions simultaneously showed his feet shrinking while his brain swelled with blood flow. This experiment was the first to reveal that when our mental ‘cogs’ turn, a boost of blood is directed to the brain. Mosso confirmed this in individuals with intact skulls with what was essentially a wobble-board bed. When people lying down on the balance thought about tricky or even particularly emotional questions, it would tip down towards the head end with the weight of the extra blood.
One of Mosso’s experiments. Each of the four traces on the right compares brain blood flow (red) and pulsations in the feet (black) simultaneously, during 1)resting 2)listening to the clock and church bells 3)remembering whether Ave Maria should have been said and 4)’8×12′?
The brain is an extremely greedy part of the body when it comes to blood. While it only makes up about a fiftieth of the body’s mass, it consumes up to a fifth of the total energy and oxygen carried in the bloodstream. Charles Roy and Charles Sherrington later proved that the blood rushing to the head was actually being diverted specifically to the parts that were most active – like a bonus for the busiest brain cells. Over twelve decades later, neuroscientists are still using this same principle to observe brain activity and the accompanying ‘rush of blood’ to the head.
Read the full article at: thebrainbank.scienceblog.com
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