We studied the effects of [Ca2+]ext changes on seal resistance in patch-clamp experiments. Recordings were made on rat peripheral and thalamic neurons. Increasing [Ca2+]ext from 0.5 to 4.5 mM, reduced the ionic currents evoked at potentials from -100 to +50 mV, in cell-attached recordings, in all the neurons tested. The effect was greater at negative potentials. The change in seal conductance (deltaG) decreased with higher resistance seals and became very low over 1 Gohm (<0.5 nS). However, the ratio deltaG/G(0.5 Ca2+) rose from close to 0 up to 0.6, indicating that Ca2+ has a stronger effect when the microelectrode and the membrane are sealed more tightly. These findings suggest that changes in seal resistance may be misleading in experiments in which extracellular Ca2+ changes are used.
|Titolo:||Effects of extracellular Ca2+ on membrane and seal resistance in patch-clamped rat thalamic and sensory ganglion neurons|
FORMENTI, ALESSANDRO (Primo)
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Data di pubblicazione:||21-gen-2000|
|Digital Object Identifier (DOI):||10.1016/S0304-3940(99)00951-9|
|Appare nelle tipologie:||01 - Articolo su periodico|