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Cortical spreading depression (CSD) is a wave of electrophysiological hyperactivity followed by a wave of inhibition, usually in the visual cortex.〔Dodick DW & Gargus JJ (August 2008). ("Why migraines strike". ) ''Scientific American''.〕 ==Uses of the term== Neuroscientists use the term cortical spreading depression to represent at least one of the following cortical processes: * The spreading of a self-propagating wave of cellular depolarization in the cerebral cortex. * The spreading of a wave of ischemia passing through an area of cortex. * The spreading of a wave of vasoconstriction following vasodilation and prolonged sustained vasoconstriction of contiguous cortical arterioles. The scintillating scotoma of migraine in humans may be related to the neurophysiologic phenomenon termed the spreading depression of Leão. The spreading depression wave progresses across the cortex at approximately 2–5 mm/minute. Increased extracellular potassium ion concentration and excitatory glutamate contribute to the initiation and propagation of cortical spreading depression, which is the underlying cause of migraine aura.〔Richter and Lehmenkühler (2008)〕 Chronic daily administration of migraine prophylactic drugs (topiramate, valproate, propranolol, amitriptyline, and methysergide) dose-dependently suppressed frequency of CSD induced by continuous cortical application of 1 M KCl solution. However lamotrigine (a drug with specific anti-aura action, but no efficacy in migraine in general) has a marked suppressive effect which correlates with its rather selective action on the migraine aura. Valproate and riboflavin were shown to have no effect on the triggering of cortical spreading depression though they are effective in migraine without aura. Taken together, these results are compatible with a causal role of cortical spreading depression in migraine with aura, but not in migraine without aura. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「cortical spreading depression」の詳細全文を読む スポンサード リンク
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