Figure 2. Increase in Cacna2d4 expression in two models for epilepsy. Egr1 (A) and Cacna2d4 (B) mRNA expression of total hippocampi 2 h after pilocarpine-induced SE (n = 8) and hippocampal CA1 6 h (n = 6), 12 h (n = 5), 3 d (n = 5), 10 d (n = 5), and 28 d (n = 6) after pilocarpine-induced SE (Egr1: 2 h: 61-fold increase; p < 0.0001, 6 h: 18-fold; p = 0.0002. Cacna2d4: 12 h: 7.8-fold; p = 0.0005, 3 d: 11.1-fold; p = 0.0002, 10 d: 12.1-fold; p < 0.0001, 28 d; 2.3-fold). p = 0.03. *p < 0.05. ***p < 0.001. C, Coupled differential equations of Egr1 protein and Cacana2d4 mRNA levels (inset) reveal slow and long-lasting transcriptional regulation following a spike-like increase in Egr1 mRNA. A, B, Red and blue circles represent the mean values of mRNA levels, respectively, following SE. Red line indicates the approximation of Egr1 mRNA by a biexponential function. Dashed gray line indicates relative levels of the assumed intermediary, Egr1 protein. The output of the model well predicts the time course of Cacna2d4 levels between SE and the chronic phase (blue line). For more details, see Materials and Methods. D, Representative pictures of RNAscope hybridization in hippocampal sections of control (left) and pilocarpine-induced SE (right) mice 6 d after SE using probes targeting Egr1 (green) and Cacna2d4 (red). Hoechst was used to stain the nuclei. Scale bars, 10 μm. E, Two representative cells expressing both Egr1 (green) and Cacna2d4 (red) mRNA in a hippocampal slice from a pilocarpine-induced SE mice 6 d after SE. Nuclei stained with Hoechst (blue). Scale bars, 10 μm. F, Cacna2d4 mRNA expression of hippocampal CA1 1, 2, 3, 5, 10, and 28 d after KA-induced SE: 1 d: 4.3-fold (sham: n = 8; SE: n = 7), 2 d: 8.3-fold increase; p = 0.0027 (sham: n = 6; SE: n = 5), 3 d: 9.3-fold; p < 0.0001 (sham: n = 11; SE: n = 10), 5 d: 5.6-fold; p = 0.02 (sham: n = 8; SE: n = 7); 10 d: 5.3-fold; p = 0.03 (sham: n = 6; SE: n = 8), 28 d: 29-fold; p = 0.0036 (sham: n = 16; SE: n = 17). *p < 0.05. **p < 0.01. ***p < 0.001). G, Cacna2d4 expression in hippocampal tissue of patients with lesion-associated TLE (LA; n = 35) versus hippocampi from patients with HS (n = 79). *p = 0.025 (t test).