Table 1. Table 1 summarizes the solvents used for the stem solutions, the concentration of the stem solutions, the concentration of the working solutions, the volume injected, the concentration in the vitreous body based on an estimated volume of 50 µl [50] up to 100 µl (own measurements in older animals (>400 g), and the number of tests performed.

substance	solvent	stem solution	working solution	volume	concentration in vitreous	tests (effective)
bumetanide	ethanol	100mM	300µM	10µl	30–60µM	21 (17)
furosemide	acetone	25mM	250µM	10µl	25–50µM	8 (7)
APB	0.9% NaCl	55mM	0.4–10mM	5–10µl	40–200µM	25 (22)
PTX	0.1M PBS	2.5mM	1mM	5–10µl	100–200µM	10 (10)

Numbers in parentheses give the number of tests where drug administration resulted in changes of the neuronal activity. APB: 2-amino-4-phosphonobutyrat; PTX: picrotoxin; PBS: phosphate buffered saline.