Fragile X Protein Linked to Potassium Channels

Mouse models of fragile X syndrome show defects in two kinds of potassium channels — ubiquitous pores that control the flow of electrical current across neurons — in a brain area that processes sound, according to two papers published this summer.The syndrome results from the absence of the fragile X mental retardation protein, or FMRP, often leading to mental retardation, delayed speech and autism. Although it is a little-studied phenomenon, anecdotal reports have shown that many people with fragile X syndrome are particularly sensitive to loud sounds and have fluctuations in their speech. An estimated one in four people with the syndrome are also prone to epilepsy.The new studies suggest that unchecked signals from potassium channels could explain why people with the disorder have trouble filtering a barrage of auditory information."[The work] is the first to really look at the molecular and cellular basis of this auditory defect — that's one reason that it's a breakthrough," notes Suzanne Zukin, professor of neuroscience at Albert Einstein School of Medicine, who was not involved in the studies.Read more at...SFARI, August 2010.