Saturday, March 10, 2007

"Rhythms of the Brain"

György Buzsáki is Board of Governors Professor at the Center for Molecular and Behavioral Neuroscience, Rutgers University. He has a M.D. in medicine and a Ph.D. in neuroscience.

His recent book is Rhythms of the Brain, which Nature called "a 'must read' for anyone interested in understanding the functioning of large and complex brain circuits."

He applied the "page 69 test" to Rhythms of the Brain and reported the following:
P. 69 is among the few technical, jargon-filled sections of the book. It details the important idea that without the balancing act of inhibitory interneurons no useful brain activity can be sustained. Two fundamental cortical network operations, pattern completion and pattern segregation, are made possible by the inhibitory interneuron system, and these processes introduce non-linearities in principal cell computation. Coordinated inhibition secures that excitatory trajectories are properly routed and the competing cell assemblies are functionally segregated. As a result, in response to the same input, a given network can produce different output patterns at different times, depending on the state of inhibition. The opposing actions of excitation and inhibition also support oscillations, and interneuron networks are the backbone of oscillation-based synchronizing mechanisms. As such, this section leads to the main thrust of the book, i.e., the rhythms of the brain. Rhythms in cortical neuronal networks come in a variety of forms that cover five orders of magnitude time scale, and their consortium allows for the multiple temporal and spatial organization of brain functions. In the ‘small world network’-like organized cerebral cortex the multiple oscillators are responsible for the self-organized, ever changing electrical patterns that allow for transient, yet dramatic increases of local excitability in short time windows, a requirement for processing and sending messages. Importantly, such self-sustained activity is the likely source of our cognitive abilities. Activity in neuronal systems (eg., cerebellum) that lack local-global organization and ‘spontaneous’ activity is not associated with conscious experience.

We have known for long that rhythms control some basic physiological functions. But only in recent years we have begun to suspect that the brain's constantly active rhythms are essential to its deepest and most general functions. Understanding these complex mechanisms has required insights from physics, engineering, and cognitive psychology with contributions from cellular, systems, cognitive, and theoretical neuroscience. The book highlights and integrates the main discoveries of these cross-roads.
Visit the complete list of books in the Page 69 Series.

--Marshal Zeringue