Table 1.

Comparison of [Ca²⁺]_i and [Na⁺]_i at 2 min following washout in Ca²⁺-free, Na⁺-free, or Ca²⁺- and Na⁺-free buffers

Condition	[Ca2+]1 (%)	[Na+]1 (%)
Control	33.6 ± 4.7	73.7 ± 4.9
Ca2+ free	23.5 ± 4.0	80.0 ± 2.6
Na+ free	63.2 ± 4.8 *	47.4 ± 4.5 *
Ca2+, Na+ free	24.6 ± 3.4	55.3 ± 3.7 *

Neurones were stimulated with kainate (100 μm) for 15 s. Values shown are the respective intracellular ion concentration measured 2 min after agonist washout as a percentage of the peak value determined in the presence of agonist. The fluo-3 signal was measured as background-subtracted fluorescence intensity, while the SBFI data have been converted from ratios into [Na⁺]_i as described in Methods. These data represent means ±s.e.m. of 5 different coverslips, with 10-36 cells for each coverslip.

^*Significantly different from control (P < 0.05, ANOVA with Dunnett's correction for multiple comparisons).