Skip to main content
. 2021 Feb 5;10:e64434. doi: 10.7554/eLife.64434

Figure 5. KCNQ2-DEE neurons exhibit a dyshomeostatic increase in SK and BK channel function.

Figure 5.

(A) Experimental protocol. Baseline measures were made after establishing the whole-cell configuration in current-clamp mode. After exactly 10 min of continuous perfusion of 500 nM apamin in aCSF, the AP properties and post-burst AHP were measured. (B) Representative traces showing post-burst AHPs before and after apamin application. (C) Acute application of apamin significantly reduced mAHP (***p=0.0004) and sAHP (***p<0.0001) in Q2-04R581Q/+ neurons and reduced mAHP in isogenic control neurons (mAHP: *p=0.0114) but not sAHP (sAHP p=0.132). However, the magnitude by which apamin reduced both mAHP and sAHP was significantly larger in Q2-04R581Q/+ neurons (t-test: ***p=0.0001, ***p<0.0001, respectively). (D) Right: Experimental protocol. Apamin (500 nM) and paxilline (20 µM) were added to MEAs after 5 min of baseline spontaneous recordings. The effect of drugs was measured after 10 min of continuous recording for 5 min. These K+ channel inhibitors reduced ISI CoV (**p=0.0015), spikes/burst (***p<0.0001) and % of all spikes that occur in bursts (***p<0.0001) in Q2-04R581Q/+ neurons. The number of spikes per burst were reduced in isoQ2-04+/+ neurons (*p=0.0051) but ISI CoV and burst % were not changed (p=0.796, p=0.0687, respectively). The magnitude by which apamin and paxilline reduced ISI CoV, spikes/burst and burst % was significantly larger in Q2-04R581Q/+ neurons (t-test: **p=0.0048, *p=0.0087 and *p=0.0254, respectively). Repeated measures ANOVA was used to compare drug effects and posthoc t-tests were used where the interaction of before/after drug and genotype was significant. A dotted line is drawn through the mean baseline values measured for isoQ2-04+/+ neurons before acute application of apamin and paxilline. Number of neurons analyzed is displayed within the figure; values displayed are mean ± SEM.

Figure 5—source data 1. Quantification of current-clamp parameters before and after acute apamin treatment for Figure 5A–C.
Figure 5—source data 2. Quantification of MEA data parameters before and after acute apamin and paxilline treatment for Figure 5D and Figure 6—figure supplement 3.