Fig. 1. Staining of taste receptor cells is concentration dependent. The histograms demonstrate the increase in number of stained taste receptor cells and of taste buds containing stained receptor cells with increasing concentration of the stimulant amino acid L-cysteine together with 1 µmol l^–1 FM1-43, over a 2 min exposure. Means of two fish. The control is 1 µmol l^–1 FM1-43 alone. Cells were counted in the anterior region of the lips, tongue and vomer.