ISSN:
1432-2013
Schlagwort(e):
Snail Neurones
;
Veratridine
;
Aconitine
;
Tetrodotoxin
;
Schneckennervenzellen
;
Veratridin
;
Aconitin
;
Tetrodotoxin
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary 1. The effect of veratridine on the electrical properties of giant neurones in the sub-oesophageal ganglion of the snail Helix pomatia has been investigated. 2. Veratridine (10−5 g/ml) caused a depolarization of 14–30 mV. Some of the cells showed slow oscillatory potential changes. The depolarizing effect of veratridine was absent in Na-free saline. 3. Veratridine drastically changed the current-voltage relation: Under voltage clamp conditions the curve was N-shaped, i.e. a branch of negative resistance was obtained. In the current clamp, therefore, a hysteresis curve was observed. The effect depended on the presence of external sodium. 4. Veratridine gave rise to large after-depolarizations of more than 40 sec duration following a short train of spikes. The after-depolarization, but not the spikes, disappeared in Na-free solution. 5. Tetrodotoxin (5×10−6 g/ml) did not influence the veratridine depolarization, the current-voltage curve, the after-depolarization or the spike height. 6. The effects of veratridine are explained by assuming that the alkaloid induces a slow sodium permeability which is voltage dependent and not sensitive to tetrodotoxin. 7. Aconitine (10−4 to 10−3 g/ml) had no effect on the resting potential, the current-voltage relation or the action potential.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00586566
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