Fig. 5

Autaptic responses contain no NMDA component. a Schematic drawing of layer-5 PC recording in Mg²⁺-free ACSF (0 Ca²⁺, 8 mM Sr²⁺) but with a cocktail of drugs that enhances NMDA responses (Gly), blocks AP generation (TTX), and mIPSCs (PTX). The Cs⁺ pipette solution makes the cell electrically more compact and allow efficient propagation of voltage pulses to autaptic contacts. b Desynchronized autaptic currents induced by somatic voltage pulses could be completely blocked by 10 μM NBQX. Scale bars: 1 s/50 pA. Inset: an expanded trace showing autaptic current events, scale bars: 50 ms/50 pA. c Group data showing current noise levels pre and post pulse stimulation, before and after NBQX application (paired Student’s t-test). d Average traces of aEPSCs and baseline mEPSCs before and after APV (50 μM) application. Scale bars: 10 ms/10 pA. e Group data showing the effect of APV on the decay time constant of aEPSC and mEPSC (paired Student’s t-test for both). Data are represented as mean ± SEM. ***P < 0.001; ns not significant