A colourful odyssey through the brain

A new book presents brains visuals from early black and white sketches to colour-infused depictions of neurons

The last few decades have produced an explosion of new techniques for probing the brain in search of the thinking,feeling,suffering,scheming mind. But the field remains technologically complicated,out of reach for the average nonscientist,and still defined by research so basic that the human connection,the usual hook by which abstruse science captures general interest,is often missing.

Carl Schoonover took this all as a challenge. Schoonover,27,is midway through a Ph.D. programme in neuroscience at Columbia,and thought he would try to find a different hook. He decided to draw the general reader into his subject with the sheer beauty of its images.

So he has compiled them into a glossy new art book. Portraits of the Mind: Visualizing the Brain From Antiquity to the 21st Century,newly published by Abrams,includes short essays by prominent neuroscientists and long captions by Schoonoverbut its words take second place to the gorgeous imagery,from the first delicate depictions of neurons sketched in prim Victorian black and white to the giant Technicolour splashes the same structures make across 21st-century LED screens.

Scientists are seduced by beauty. Schoonover knows this firsthand,as he acknowledged in an interview: for a while his wallet held snapshots not of friends or family,but of particularly attractive neurons. Sometimes the aesthetics of the image itself captivate. Sometimes the thrill is the magic of a dead-on fabulous technique for getting at elusive data.

Consider,for instance,a blurry little black-and-white photograph of a smiley-face icon. The picture is actually a miracle in its own right: the high-speed video camera that shot it was trained on the exposed brain of a monkey staring at a yellow smiley face. As the monkey looked at the face,blood vessels supplying nerve cells in the visual part of the monkeys brain swelled in the same pattern. We can tell what was on the monkeys mind by inspecting its brain.

The challenge of understanding the brainas resistant to study as a giant mass of tightly packed cold spaghettiwas twofold: what did that neural pasta really look like,and how did it do what it did? In 1873 the Italian scientist Camillo Golgi developed a black stain to highlight the micron-thin neural strands. Fifteen years later the Spanish scientist Santiago Ramón y Cajal,presented the world for the first time with visible populations of individual neurons,looking for all the world like burnt scrub brush in a postapocalyptic Dalí landscape.

Now those same skeletal silhouettes glow plump and brightly coloured,courtesy of a variety of inserted genes encoding fluorescent molecules.

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One team of researchers harnessed the rabies virus,which has the ability to travel upstream against the neural current. The virus moves from a leg bitten by a rabid dog up the long axons leading to the spinal cord and jumps to dendrites of other nerves and travels up to the brain. The traffic in long groups of neurons all coursing together around the brain becomes visible with a variation on the scanning technique called diffusion M.R.I. Here the neurons do look like pastaangel hair,perhapsslightly beaded,and draped. But if the structure is destroyed for instance,by a stroke the strands shatter into fragments.

People assumed for thousands of years that there must be something else, the science writer Jonah Lehrer writes in the introduction. And yet,there is nothing else: this is all we are.