Blockade of voltage-gated calcium channels in rat inhibits repetitive cortical spreading depression.
Blockers of L-, N-, and P/Q-type voltage-gated calcium channels (VGCCs) were topically applied to the cortical surface of anaesthetized adult rats to study their role in cortical spreading depression (CSD), a correlate of the migraine aura. By pricking the brain, single CSD could still be elicited after blockade of the three different types of VGCCs as in the untreated brain. Topical KCl application to the untreated cortex resulted in repetitive CSD. However, after application of blockers at either L-, or N-, or P/Q-type VGCCs to the cortical surface, application of KCl elicited only one or very few CSD, and their repetition rate was dramatically reduced. The results suggest that cortical excitability resulting in repetitive CSD is markedly influenced by N- and P/Q-type VGCCs and less by L-type VGCCs.
Richter
Frank
F
Department of Physiology, Friedrich Schiller University of Jena, Teichgraben 8, D-07740 Jena, Germany. fric@mti-n.uni-jena.de
Ebersberger
Andrea
A
Schaible
Hans-Georg
HG
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D013181:Cortical Spreading Depression / Q000187:drug effects* / Q000502:physiology; D008297:Male; D020325:Migraine with Aura / Q000503:physiopathology; D009553:Nimodipine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D020867:omega-Agatoxin IVA / Q000494:pharmacology; D020960:omega-Conotoxins / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D020867:omega-Agatoxin IVA; D020960:omega-Conotoxins; D009553:Nimodipine; D011189:Potassium Chloride