NCX easily reverses its direction and brings Ca2+ into the cells if the Na+ concentration gradient decreases and/or the membrane potential becomes less negative.
The energy state of the mitochondrial membrane has additional effects on mitochondrial fission and fusion because mitochondria with lower membrane potentials are less likely to undergo fusion events (Twig et al, 2008).
Finally, the burst frequency (Fig. 3D) increased as the membrane potential was increasingly less hyperpolarized in three out of the six experiments.
By contrast, EPSCs with τrise/τdecay of 0.1/8, 0.1/20, 5/50, 23/50, 5/83, 5/200 and 50/250 ms resulted in correspondingly slower changes in membrane potential and elicited temporally less precise spike responses with a average STP of Δt = 7.65 ms, s.e.m. = 0.37 ms (Figure 2A).
The effects of membrane potential on IP3R are less clear, with suggestions that IP3R activity is either unaffected (192, 193) or weakly enhanced by depolarization (194, 195).
Patch-clamp is often considered to give a more direct measurement of channel activity, without membrane potential changes, and with less modulation of the net signal by other mechanisms such as Ca2+ uptake and extrusion.
The reason for this can be intuitively understood: a steep action potential enables the axon to respond fast to rapid membrane potential changes, whereas a less steep action potential onset will not be fast enough and, in the extreme case, it will "ignore" the underlying voltage modulations.
The membrane potential was found to be less negative in β2−/−/γ3−/− mice (Fig. 4C) consistent with the observation that the very negative membrane potential of Müller cells depends on the dominant Kir conductance [43], [44].
When higher concentrations of DASPMI are used to measure mitochondrial membrane potential, other possible localizations and less specific staining will decrease its sensitivity to mitochondrial membrane potential.
Human induced pluripotent stem cell (hiPSC) cardiomyocytes (CMs) show less negative resting membrane potential (RMP), which is attributed to small inward rectifier currents (IK1).
