Figure 3. In ganglion cells classified as category 3, a GABAB receptor antagonist did not affect bipolar cell output unless ionotropic GABA receptors were blocked.
A, application of 5 μm CGP55845 (black trace) had little effect on EPSCs compared to control. B, after application of 100 μm PTX, 5 μm CGP55845 reduced mainly the ON EPSC (black trace, n= 12) and this effect was reversible. C, when the IPSC was monitored in the same cell, 5 μm CGP55845 reversibly enhanced the IPSC in the presence of 100 μm PTX (n= 12) and this effect was reversible.