February 16, 2010
Neuroscientists Reveal New Links That Regulate Brain Electrical Activity
Ion channels traditionally thought to work independently actually work in sync
Investigators in the Hotchkiss Brain Institute, Faculty of Medicine, have made a major breakthrough in our understanding of nerve impulse generation within the brain. Brain cells communicate with each other by firing electrical impulses, which in turn rely upon special ion channels that are positioned at strategic locations in their membranes. This exciting, new foundational research was published this week in the prominent journal Nature Neuroscience.Principal Investigators, Ray W. Turner, Ph.D. and Gerald Zamponi, Ph.D. study the inhibitory and excitatory actions of ion channels in neurons of the cerebellum. Partnerships between the two laboratories, enabled Turner to 'follow his hunch' to prove that specific members of two different families of channels, previously thought to function independently, in fact function in tandem.
"A-type" potassium channels exhibit unique properties to control the timing of neuronal output. Turner's team found that these channels physically link with a class of "T-type" calcium channels that enhances their ability to control nerve impulse timing. Interestingly, T-type calcium channels also exhibit unique properties compared to other members of their family - which in retrospect forms a perfect match between the members of this new signaling complex.
"The first results that revealed this link were amazing," says Turner about this discovery. "These new developments redefine how we should look at the control of neuronal activity. They not only indicate how the timing of impulses from the cerebellum are controlled, but also predict how electrical activity in other parts of the brain is generated."
In addition to providing scientists fairly accurate ideas as to electrical regulation throughout the brain, this research may also advance pharmacological therapies for a number of neurological disorders such as epilepsy, and movement disorders such as tremor or ataxia.
Dustin Anderson, Turner's Ph.D. student and first author on the paper explains the relevance of this work in another way. "When you have a machine as complex as the human body, understanding the components, or in this case the behavior and reactions of cellular activity, provides health researchers and physicians with answers as to how the body works and what happens when things go wrong."
This research was supported by the Canadian Institutes of Health Research. R Turner and G. Zamponi are Alberta Heritage Foundation for Medical Research (AHFMR) Scientists Turner is a Professor in the Department of Cell Biology & Anatomy and Zamponi is Head of the Department of Physiology & Pharmacology. Both are full members of the Hotchkiss Brain Institute in the Faculty of Medicine at the University of Calgary. G. Zamponi is a recipient of a Canada Research Chair Tier I. D. Anderson holds an AHFMR Studentship and a T. Chen Fong Doctoral Scholarship in Neuroscience.
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