Figure 8.

Blockade of ON bipolar cell function in combination with inhibitory antagonists in the WT retina can enhance the emergent long-latency ON response. APB, an mGluR6 agonist that blocks the short-latency ON response, can enhance the long-latency ON response that emerges in the WT retina when inhibitory receptors are antagonized. A–D, The top panels show examples of the responses of WT neurons to 3 s light stimulus presentations in control saline. The middle panels show the responses of these same neurons in the presence of GABA_A, GABA_B, GABA_C, and glycine receptor antagonists. The bottom panels show the responses of these same neurons in the presence of APB (100 μm) in addition to the inhibitory receptor antagonists. In all cases, APB eliminated the short-latency ON response. In D, the ON neuron gained an OFF component to its response in the presence of the inhibitory receptor antagonist cocktail only exhibited a long-latency ON response once APB was added. Light/dark bars show the timing of the light stimulus. Frequency (Freq) is in impulses (spikes) per second (imp/sec).