Growth Cone

Reading "The Other Brain," R. Douglas Fields, Ph.D. It's about glia, the glue that makes up 85 percent of the stuff in our brain. Like dark matter, an equal percentage of the universe, we knew it was there, but didn't know what it was for. Santiago Ramon y Cajal, an artistic child who drew well and loved photography became a medical doctor to earn a living. In 1887, Cajal saw a slide of nervous tissue stained by the Italian anatomist Golgi 14 yrs. earlier. Cajal left bacteriology and took the chair of Normal and Pathological Histology in Barcelona, intent on improving Golgi's staining method to unravel the cellular structure of the brain. As an artist, he drew accurate silhouettes of neurons. He received the Nobel Prize in Physiology in 1906 with Golgi for this work.

But what he left out of his neuron illustrations is what we now know is the 85% of the brain not neurons. He never drew what was not there. He saw glia clearly, but he did not include it in his neuroanatomical drawings. He saw the cells, drew the mystery formations copiously elsewhere, filling volume after volume with drawings, called them "spider cells" but their function was unknown. Glia's secret life is beginning to be revealed.

Pictured is a "growth cone" - what Fields calls "one of the most beautiful and dynamic cellular structures in nature." Axon seeking a path to reconnect with a lost connection (due to nerve damage), protein guiding it to avoid obstacles, refuse false turns, and stay on the true path. Glia cells include astrocytes, oligodendrocytes and microglia in the peripheral nervous system, and Schwann cells in the central nervous system.

Science that acts like magic. Great beauty is within us and around us, even if we can't see it, and if we do see, don't know its purpose, until we look closer.