Different effects of 4-aminopyridine on sensory and motor fibers: pathogenesis of paresthesias.
Mammalian motor and sensory fibers respond differently to the potassium channel-blocking agent, 4-aminopyridine (4-AP). The action potentials of the motor fibers increase in duration after 4-AP, while the sensory fibers respond with bursts of action potentials after a single stimulus. These differences may account for the paresthesias reported by patients with multiple sclerosis following treatment with 4-AP.
D015761:4-Aminopyridine; D000200:Action Potentials / Q000187:drug effects; D000631:Aminopyridines / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D001369:Axons / Q000187:drug effects; D009043:Motor Activity / Q000502:physiology*; D009103:Multiple Sclerosis / Q000188:drug therapy; D009412:Nerve Fibers / Q000187:drug effects*; D010292:Paresthesia / Q000209:etiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012677:Sensation / Q000502:physiology*; D013126:Spinal Nerve Roots / Q000187:drug effects
D000631:Aminopyridines; D015761:4-Aminopyridine