Joseph Jebelli reviews ‘The Other Brain: The Scientific and Medical Breakthroughs That Will Heal Our Brains and Revolutionize Our Health’ by R. Douglas Fields.
Ask any academic studying the brain what the fundamentals of basic brain function are and you will almost certainly receive a lengthy monologue on neurons, synapses, and the electrical properties underlying learning and memory. But as Douglas Fields explains in this informative book, only 15% of the brain is comprised of neurons – what about the other 85%!? This ‘Other Brain’ represents another wholly different cell type, collectively known as glia.
Whilst neuroscientists have known about glia for over a century, they have been largely ignored, being regarded as mere passive support cells. It is on this note that Fields begins. Part 1 of the book outlines the history behind the so-called ‘neuronal doctrine’ and recounts the very first glimpses of the brains microscopic structure by the pioneers of modern neuroscience, including Ramon y Cajal, Camillo Golgi and Theodore Schwann. Grounded in the peculiar post-mortem observations of Einstein’s brain, this part of the book offers the reader a good lay overview of the basic cellular components of the brain, and the historical settings in which they were discovered.
Fields goes on to discuss how the technique employed by neuroscientists to study brain cells, namely electrophysiology, restricted their focus to the electrical properties of neurons. As electrically passive cells, glia communicate in other ways (e.g calcium signalling), and it is only now that we are beginning to appreciate just how widespread and crucial this method of communication is for basic neurobiology. His referencing is sound, citing a plethora of cutting-edge research, which does a great deal to put the reader at ease over the veracity of his claims.
The second part of the book is a thought-provoking and comprehensive discussion on the significance of glial cells to nearly all maladies of the brain, from Alzheimer’s and Parkinson’s to cancer, pain, and addiction. Fields manages to deliver a succinct report of recent discoveries on the role of glia in each disorder, whilst also putting forward many unanswered issues left to resolve. Particularly gripping is his chapter on scientist’s first encounter with the infectious prion protein, discovered by Dr Carleton Gajdusek in the 1950s, whilst living with and treating a cannibalistic forest tribe in eastern New Guinea afflicted by a disease known locally as ‘Kuru’. The letter excerpts from communications between Gajdusek and research colleagues back in the states vividly brings to life a powerful tale of adventure, endurance and a discovery that started a new field and is shaping others to this day.
Nonetheless, whilst I thoroughly enjoyed the second parts sweeping account on the role of glia in different brain disorders, there are occasions where the author overstates the implications of particular findings – a habit most likely picked up from years of writing research grants! What’s more, the lay style of writing that was evident at the beginning starts to fade as the book progresses, leaving me inclined to suggest that, on the whole, this may be more a popular science book for scientists than the lay public.
The final part of the book is more theory than fact, describing the overarching implications of glial cell biology to higher human faculties such as memory and consciousness. As a neuroscientist myself, I know that many in the field do not believe the binary electrical signalling between neurons is sophisticated enough to give rise to the higher human faculties, and that neuronal-glial cell communication may represent the true cellular substrate of such phenomena. As Fields points out, recent findings have shown glia can actually control neuronal excitability; a fact that certainly bestows these cells more prominence than the archaic notion of a passive support cell!
Although glial biology is still very much in its infancy, this book is an excellent guide to an exciting paradigm-shift occurring in neuroscience. I highly recommend it for anyone interested in our current understanding of the brain, and deem it mandatory reading for anyone who, like myself, spent too much time learning about neurons during their undergraduate studies.
Joseph Jebelli is a Neuroscience PhD Candidate at University College London (UCL) studying the cellular and molecular mechanisms of neurodegenerative disease.