The effects of sudden osmotic downshock (open circles, blue line) and of sudden osmotic downshock followed by immediate return to previous osmotic conditions (triangles, red line), in comparison to a control where no downshock was administered (filled circles, black line), on the uptake of ¹⁴C-choline by C. psychrerythraea 34H at –1°C. DPM values have been scaled to volume, accounting for dilution factors involved in experimental manipulations. Error bars indicate S.D. of the mean (n = 3 before the downshift, n = 2 afterwards); where no bar is visible, it falls within the dimensions of the symbol for the mean.