Figure 7.

Substance P suppresses evoked IPSCs via retrograde endocannabinoid signaling. A–D, Averaged traces of evoked IPSCs before (Pre) and during substance P (SubP, 300 nm) in the presence of AM251 (A, 3 μm), AM281 (B, 3 μm), intracellular GDP-βS (C, 2 mm, added to the recording pipette solution) and THL (D, 10 μm). E, Bar chart of the mean amplitude of evoked IPSCs (eIPSC Ampl) in the presence of substance P, expressed as a percentage of the predrug control (Ctl) level, in neurons treated with AM251, AM281, GDP-βS, and THL compared with untreated control neurons. *p < 0.05; **p < 0.01; ^##p < 0.0001. A–D are taken from different neurons.