ISSN:
1432-2013
Keywords:
Neuroblastoma cell
;
Patch clamp
;
Single sodium channel
;
Multiple open states
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Single sodium channel currents were studied in mouse neuroblastoma cells. Channel conductance (γ) was 11.6±3.4 pS at 6–8°C. Unitary current amplitudes and channel activity increased with increasing temperature. The Arrhenius plot of the conductance was linear between 5 and 35°C with an activation enthalpy of 27.1 kJ/mole (Q 10 =1.28). Amplitude distributions were fitted by the sum of two Gaussian functions indicating the presence of two different single channel amplitudes: smalleri 1 and largeri 2. The relative probability of appearance ofi 1, which has a shorter mean open time, was higher during the early phase of depolarization (t〈16 ms). The open time histograms, inactivating phase of macroscopic currents and delay time histograms were fitted by the sum of two exponentials. The distinct kinetic and steady-state parameters reflect two open states of sodium channels.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00652757
