Figure 6.

Enhancement of glutamate release from cultured cerebellar granule cells. (A) Cultured rat cerebellar granule cells were incubated for 20 min in the presence or absence of 20 μM PP2 (or PP3) in low-K⁺ solution in a water bath at 37°C. After treatment, cells were washed three times and incubated for 2 min each in low-K⁺ solution (open bars) and low-K⁺ solution with 5 μM ionomycin (hatched bars) sequentially to evoke neurotransmitter release. The amount of glutamate released into the medium was determined. The values are the mean ± SEM from four representative experiments. (B) Cultured rat cerebellar granule cells were incubated for 5 min in the presence or absence of 20 μM latrunculin A in low-K⁺ solution in a water bath at 37°C. After treatment, cells were washed three times and incubated for 1 min each in low-K⁺ solution (open bars) and low-K⁺ solution with 3 μM ionomycin (hatched bars) sequentially to evoke neurotransmitter release. The amount of glutamate released into the medium was determined. The values are the mean ± SEM from eight representative experiments.