Electrophysiology of the giant nerve cell bodies of Limnaea stagnalis (L.) (Gastropoda: Pulmonata).

摘要: 1. A mean resting potential of -53.3 (S.D. ±2.7) mV has been obtained for 23 neurones the parietal and visceral ganglia Limnaea stagnalis (L.). Changes in between 28 43 accompany tenfold changes [K+0]. modified constant-field equation accounts behaviour most cells over range external potassium concentrations from 0-5 to 10.o mM/1. Mean values have estimated [K+1, 56.2 (S.D.± 9-0) mM/1 PNa/PK, 0-117 (S.D.±0-028). 2. Investigations on ionic basis action generation revealed two cell types which can be distinguished according their potentials sodium-free Ringer. Sodium-sensitive are unable support more than 8-10 min absence sodium. Sodium slopes 29 37 per decade change [Na+0] found these cells. Tetrodotoxin (5 x 10-5 M) usually blocks neurones. Calcium-free inger produces a marked reduction overshoot calcium about 18 [Ca2+o] found. Manganous chloride only partially reduces at 10 mM/l. 3. Sodium-insensitive maintain Stimulation slightly amplitude under conditions such readily accessible ions bathing medium. calcium-slope observed 4. It is concluded that both sodium involved stagnate, relative contribution varying different