2005 2 Animum rege, qui nisi paret, imperat. distribution and neuronal localization of c-fos protein in the rat hippocampus following 4-aminopyridine seizures.competitive NMDA receptor antagonists moderate seizure-induced c-fos expression in the rat cerebral cortex. Z.: Alterations of seizure-induced c-fos expression in the rat cerebral cortex following dexamethasone treatment. (submitted) V.fo...

Acrolein-mediated myelin damage is thought to be a critical mechanism leading to conduction failure following neurotrauma and neurodegenerative diseases. The exposure and activation of juxtaparanodal voltage-gated K(+) channels due to myelin damage leads to conduction block, and K(+) channel blockers have long been studied as a means for restoring axonal conduction in spinal cord injury (SCI) a...

At the crayfish opener neuromuscular junction, axons branch repeatedly before synapsing onto muscle fibers as varicosities. Excitability of these axons was examined with two-electrode current clamp before and after partial block of Na(+) channels with 1 nM tetrodotoxin. 4-Aminopyridine (200 μM) was added to homogenize nonuniformity in K(+) channel density. The impact of tetrodotoxin was evaluat...

The aim of the study is to demonstrate the presence of intracellular calcium store in frog ventricle based on contractures induced by 4-aminopyridine in calcium-free media. Frog-ventricular strips were subjected to field stimulation at 0.2 Hz and the force of contraction was recorded after stabilization. The preparation was then kept quiescent for some time in solutions with different sodium co...

Effect of 4-aminopyridine (4-AP) on the potassium permeability of the cell membrane of canine tracheal smooth muscle was investigated using 86Rb-efflux. The 86Rb-efflux from the strip was remarkably increased by 20 mM 4-AP in normal physiological solution in the presence of 1 microM atropine. In high potassium and chloride deficient solution, 4-AP (0.3-20 mM) decreased the rate of 86Rb-efflux i...

BACKGROUND AND PURPOSE We postulated that some abnormalities in cerebrovascular function after subarachnoid hemorrhage (SAH) may involve underlying alterations in K(+) channel function. Thus, using pharmacological inhibitors, we assessed the influence of SAH on function of 2 types of K(+) channel in regulation of basilar artery diameter in vivo and membrane potential (E(m)) in vitro. METHODS ...

INTRODUCTION: 4-Aminopyridine (fampridine), a potassium channel blocker, has demonstrated efficacy in improving lower extremity strength and walking speed in patients with multiple sclerosis. Since in vitro electrophysiologic studies are recommended for evaluating a drug's potential to prolong the QT interval and induce such cardiac arrhythmias as Torsades de Pointes, we examined the electrophy...

1 4-Aminopyridine methiodide (4-APMI), a quaternary analogue of aminopyridine (4-AP), was tested for neuromuscular facilitatory actions on the chick biventer cervicis and frog sartorius nerve-muscle preparations. 2 In the chick, 4-APMI (10(-4) to 10(-2) M) augmented indirectly elicited twitches and reversed tubocurarine-induced neuromuscular block. Reversal of tubocurarine block was observed af...