“…The extracellular space was washed six times in around 15 s with Krebs solution at 2°C , so reducing the Na concentration to a negligible level with minimal changes in the concentration of intracellular ions (Lamb & McCall, 1972), and then the influx measured over1 min at 37 'C. The temperature rise from 2 to 37 'C was achieved by rapid rinsing with Krebs solution at 37 'C, and occurred with a T1 of around 5 ms and reached completion in 20 ms ( (Duggleby, 1981). As the variance is roughly proportional to the absolute value in this system, the higher value used was 5 mm and the lower value 0 5 mm in normal Na mediumn and 005 mm in low Na medium.…”