Fig. 7. Effect of 5-hydroxytryptamine (5-HT) and ionomycin on [Ca²⁺]_i in dorsolateral ciliary cells. Dorsolateral ciliary cells were microinjected with fura-2 dextran and imaged once every 15 s.Application of 100 µmol l^–1 5-HT generated two different types of changes in [Ca²⁺]_i, an early peak followed by a sustained plateau (A; N=4 cells) or a gradual rise in [Ca²⁺]_i over the course of 5-HT perfusion (B; N=6 cells). In all cells, regardless of the response, 10 µmol l^–1 ionomycin produced a variable increase in [Ca²⁺]_i. Dotted lines represent the time when the specified treatments were initiated.