A, I–V relationship of sEPSCs when (−)indolactam-V (300 μm) was included in the pipette solution (n = 7). B, (+)indolactam-V was used as a negative control (n = 7). C, inclusion of OAG in the patch electrode gave rise to a linear I–V relationship of sEPSCs (n = 5). D, rectification index of synaptic currents increased in the presence of (−)indolactam-V and OAG (DMSO control, n = 4; *P < 0.05).