Fig. 4.

Horizontal cells loaded with Oregon Green report an intracellular rise in calcium upon puff of kainate. A: intracellular calcium indicator Oregon Green BAPTA-1 AM ester, which is internalized by isolated horizontal cells, consistently reports an intracellular rise in calcium upon micropuff of 50 μM kainate. B: Oregon Green fluorescence associated with 50 μM kainate (left), 300 μM glutamate (center), and 50 μM kainate in the presence of 75 μM 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, right). *Statistically significant difference between the response to 50 μM kainate and 300 μM glutamate; **statistically significant difference in the presence of CNQX from responses induced by kainate or glutamate.