Fig. 4. Effect of non-nmda antagonists on cell tr1's output connections. Constant latency excitatory postsynaptic potentials (EPSPs) are triggered in cell 204 [left], and in the Retzius cell [right], by cell Tr1 impulses in high divalent saline [control]. In the presence of 100 mM kynurenic acid, or 50 mM DNQX, the cell Tr1-triggered EPSP is absent from cell 204 (left). Bath application of either 25 mM DNQX or 0.5 mM JSTX, similarly results in the elimination of the monosynaptic connection from cell Tr1 to the Retzius cell (right). Neither 500 mM L(+)-AP3 nor 500 mM GAMS altered cell Tr1-induced EPSPs in cell 204 (left) or the Retzius cell (right), respectively. Each trace represents 10 averaged signals. Data are from six different experiments. Stimulus artifacts were reduced for clarity. CALIBRATION: 1 mV (cell 204) and 2 mV (Retzius cell); 50 ms.