The Dynamic Neuron

The Dynamic Neuron, by John Smythies, is an important review and survey of the biochemistry literature on the neurochemical basis of synaptic plasticity.   Smythies is the Director of the Division of Neurochemistry, UC San Diego; Senior Research Fellow, Institute of Neurology, Queen Square London; and visiting Professor, Department of Psychiatry, Harvard Medical School.

Synaptic plasticity is a dramatic paradigm shift from the days of high school biology.   The synapses between neurons and overall neuronal structure were relatively fixed.   Learning and other mental processes relied on the existing network by adjusting the threshold and firing rate between the synapses.  And within the cell, proteins and other biochemical miscellanea drift around as in a soup managing to serendipitously interact, enabling the cell to function quite nicely.  Our current knowledge about synaptic plasticity paints an entirely different picture.  A cell from the inside is highly structured and functions more like a collection of coordinated mini-factories that would make a production manager envious.  And the synapses are much more frequently replaced, deleted, and built anew.  They do not die, like a branch withering on a tree.   They are actively dismantled and assembled, enabling new connections and ridding the brain of underused connections. 

The book divides itself into chapters relevant to representing the complexity of the biochemical processes underwriting synaptic plasticity.  Chapter Two explains the biochemical mechanisms involved in endocytosis and exocytosis.  Endocytosis, the process in which a substance gains entry into a cell without passing through the cell membrane, is implicated, among other things, in the growth of spines, desensitization of the receptor, and repair of oxidatively damaged proteins.   Exocytosis is the process in which neurotransmitters are released from the cell.  Chapter Three, “Special Proteins,” focuses on the proteins involved in neuritic growth and in how cells or cell bits adhere to each other and break apart.  Chapter Four, aptly titled “Miscellaneous Items,” covers the loose odds and ends surrounding the biochemistry of synaptic plasticity.  The last chapter, “Pharmacological Implications and Clinical Applications,” lays emphasis on schizophrenia and Alzheimer's disease with respect to details previously discussed.

The Dynamic Neuron is High Science.  It is not for the scientific hobbyists.   It is intended for someone actively engaged in biochemistry or neuroscience research wanting a concise review of the current scientific literature on synaptic plasticity.  The biochemistry involved is exceedingly complex.  Paragraph after paragraph reads like the following passage, haphazardly chosen, from Chapter Two; “[t]he beta adrenergic receptor is rapidly endocytosed whereas the vasopressin receptor is rapidly endocytosed, both by a clathrin-beta-arrestin mechanism.” If you found that sentence impenetrable, the book will be too.

 © 2002 James Hitt

James Hitt is a Ph.D. candidate in philosophy at the Graduate School and University Center, City University of New York.