Figure 3.
Stimulation of 5-HT7R/G12 signaling results in an increase of spontaneous neuronal activity. A, Spontaneous neuronal activity was analyzed in primary cultures of hippocampal neurons by whole-cell patch-clamp recordings at DIV11. Representative recordings from control, 5-CT (100 nm), and 5-CT (100 nm) plus SB-269970 (1 μm) treated neurons are shown. In addition, effect of 5-CT treatment was analyzed in Gα12-deficient neurons and in neurons transfected with 5-HT7 receptor siRNA. The 5-CT and 5-CT plus SB-269970 treatment was performed during the last 4 d before recording. Vhold = −65 mV. B, C, Quantitative analysis of the frequency of EPSPs (B) and action potentials (C). Values represent means ± SEM; ***p < 0.001. D, Representative images of neurons treated with 5-CT (100 nm) or 5-CT (100 nm) plus SB-269970 (1 μm). AMPARs and synaptophysin immunostaining is shown individually and as a merge. Scale bar, 10 μm. E, F, Average number of total surface (E) and synaptic AMPAR-positive (F) puncta per 50 μm of dendrite for control, 5-CT, and 5-CT plus SB-269970 treatments. Values represent means ± SEM; ***p < 0.001. WT, Wild type; KO, knock-out.