Intramembranous particle patches in myelin-deficient rat axons.
Focal accumulations of E-face intramembranous particles occur in spinal cord axons of myelin-deficient rat mutants. These resemble nodal particles and, like them, may represent voltage-sensitive sodium channels. It is proposed that axonal activity at these foci could increase extracellular potassium to the point of triggering activity in adjacent axons. Rapid spread of such potassium-induced activity among bare axons could underlie the seizures and other neurological abnormalities that develop in this mutant. A similar mechanism may account for the paroxysmal attacks sometimes seen in multiple sclerosis.
D000818:Animals; D001369:Axons / Q000648:ultrastructure*; D005614:Freeze Fracturing; D008297:Male; D009103:Multiple Sclerosis / Q000473:pathology; D009186:Myelin Sheath / Q000502:physiology* / Q000648:ultrastructure; D011901:Ranvier's Nodes / Q000648:ultrastructure; D051381:Rats / Q000235:genetics; D013116:Spinal Cord / Q000648:ultrastructure