Figure 5. Norepinephrine (NE) can augment Po of L-type Ca²⁺ channels (LTCCs) via α₁AR signaling in hippocampal neurons.

(A) Neurons were preincubated with NE ± prazosin (PRAZ) before seal formation. (B, C) Sample diaries show time courses of Po recordings obtained after preincubation with either NE alone or NE + PRAZ and seal formation. The number of channels under the patch was estimated based on the maximal number of observed stagged openings in each patch (k; upper left). (D) Ten consecutive traces from representative cell-attached single-channel recordings of LTCCs under control conditions or upon pre-incubation with either NE alone or NE plus PRAZ. Bottom panels show ensemble averages. (E) NE strongly increases Po (left) and peak currents of ensemble averages (right), which was strongly but not fully inhibited by PRAZ. Data are presented as means ± standard error of the mean (SEM; Control, n = 8 cells; NE, n = 12 cells; NE/PRAZ, n = 11 cells). Statistical significance was tested by a one-way analysis of variance (ANOVA) with Bonferroni correction, *p ≤ 0.05. Panel A was created using Biorender.com.