Figure 4.

Cesium-sensitive channels do not underlie the sublinear voltage-dependence of clusters. A) When Cs⁺ is included in the electrode to block a subset of K⁺ hannels, the amplitude of clusters is still dependent upon the membrane potential (depicted here are overlays of consecutive clusters recorded at −84, −70 and −58 mV). B) There is a reduction of cluster amplitude at depolarized membrane potentials in the presence of Cs⁺ (left). This relationship is sublinear (right; included in this analysis are only neurons with >30 mV range of data points). C) When data points from individual neurons are fit, it was found that most neurons were best-fit with a sub-linear fit compared to linear (left; red line represents a sublinear fit, green line represents a linear fit, blue line represents a supralinear fit). When the values from each neuron are normalized to their peak amplitude, the relationship between membrane potential and cluster amplitude is best fit with a non-linear relationship (right). There was no significant difference in this normalized voltage dependence between Cs⁺ and DNDS control. D) There is a reduction of cluster area at depolarized membrane potentials in the presence of Cs⁺ (left). This relationship is sublinear (right; included in this analysis are only neurons with >30 mV range of data points). E) When data points from individual neurons are fit, it was found that most neurons were best-fit with a sub-linear fit compared to linear (left; red line represents a sublinear fit, green line represents a linear fit, blue line represents a supralinear fit, grey lines connect data points from individual neurons). When the values from each neuron are normalized to their peak area, the relationship between membrane potential and cluster area is best fit with a non-linear relationship (right). There was no significant difference in this normalized voltage dependence between Cs⁺ and DNDS control.