In 1893, Santiago Ramon y Cajal, the Spanish neuroanatomist, outlined a general theory of memory that, in its essence, is almost identical to the one that is accepted today. Learning, he suggested, leaves its mark by making connections between neurons. His scientific findings were based on his detailed microscopic studies of brain cells, conveyed by his elegant drawings that were both extraordinarily accurate and beautiful to behold.  

Cajal’s landmark drawings, which are still in use by neuroscientists today, are the subject of an exhibition organized by the Weisman Art Museum, Minneapolis, Minnesota, which will open at NYU’s Gray Art Gallery in January, accompanied by a lavishly illustrated book (Abrams Books 2017).

Left: Sell-portrait by Cajal at his laboratory

Before Cajal’s discoveries, very little was known about neurons, one of the major components of gray matter. This stumbling block was due mainly to the lack of accurate methods for visualizing neurons; the early methods of staining samples for viewing under a microscope only permitted the visualization of a small portion of these complex neural components.

It was only when the Italian medical scientist Camillo Golgi (1843-1926) devised a new staining method in 1873 that neurons could be microscopically observed with all their parts clearly in relationship to one another.

Golgi-stained cells displayed the finest morphological details with an extraordinary elegance. This breakthrough enabled Cajal to delve into a detailed study that resulted in the 1906 Nobel Prize in Histology [Medicine] was shared with Goji.

Cajal would later write: “The new truth, laboriously sought and so elusive during two years of vain efforts, rose up suddenly in my mind like a revelation… Realizing that I had discovered a rich field, I proceeded to take advantage of it, dedicating myself to work, no longer merely with earnestness, but with a fury.”

In the grip of that fury, he worked fifteen-hour days and in a single year published fourteen scientific articles on the nervous system, which at the time was an enigmatic terra incognita.

L: Pyramidal neurons of the central cortex and their axon pathways. R: A Purkinje neuron from the human cerebellum

This was a high-risk enterprise in the study of a controversial subject at the end of the 19^th century, when many notable scientists attempted to unravel the mysteries of the brain. In one of the essays in the monograph, curator Lyndel King and editor Eric Himmel consider the visionary approach that elevated Cajal above the rest: “At best, a brain slice seen through a microscope is notoriously difficult to interpret. To borrow one of Cajal’s favorite metaphors, imagine entering a forest with a hundred billion trees armed only with a sketchbook, looking each day at blurry pieces of a few of those trees entangled with one another, and, after a few years of this, trying to write an illustrated field guide to the forest.

L: Diagram illustrating how information from the eyes might be transmitted to the brain. R: An astrocyte in the human hippocampus

"You won’t get anywhere if you simply draw what you see every day," Cajal suggested. "You’re going to have to build up a mental inventory of rules for the forest, and then scrupulously try to fit what you see into that framework, or be flexible enough to allow what you see to reshape your stock of ideas.”

The Beautiful Brain: The Drawings ofSantiago Ramón y Cajal is currently on view at the Morris and Helen Belkin Art Gallery, University of British Columbia, Vancouver, BC.

The exhibition opens on January 9 at Grey Art Gallery, New York University, 100 Washington Square West, NY, NY and later can be seen at the MIT Museum, Cambridge, MA.

You can read about Cajal’s Dream Journal in Nautilus