Figure 1. Depletion of cholesterol with MCD reduces evoked responses to hypertonic sucrose and action potentials.

A and B, hypertonic sucrose response after MCD treatment. A, sample traces. B, summary graph showing that the average charge transfer during the first 10 s of the 30 s sucrose stimulation is decreased 75% in cultures treated in 20 mm K⁺ with MCD. Cultures treated with 20 mm K⁺ alone were not significantly different from non-treated cultures. Treatment with MCD alone also reduced the response; however, the magnitude of the decrease was less (68%). The addition of cholesterol to MCD-treated cultures rescued the depleted hypertonic sucrose responses to values not significantly different from non-treated cultures. Horizontal bar represents the presence of hypertonic sucrose; data collected from at least 3 cultures for each condition: no treatment, n = 18; 20 mm K⁺ alone, n = 3; MCD alone, n = 16; 20 mm K⁺ with MCD, n = 18; 20 mm K⁺ with MCD + cholesterol, n = 10. C and D, field stimulation-evoked responses after MCD treatment. C, sample traces. D, summary graph depicting that the average maximum evoked EPSC amplitude is reduced 78% in cultures treated in 20 mm K⁺ with MCD. Cultures treated with 20 mm K⁺ alone were not significantly different from non-treated cultures. Treatment with MCD alone also reduced the response; however, the magnitude of the decrease was less (57%). The addition of cholesterol to MCD-treated cultures rescued the reduced EPSC amplitudes to values not significantly different from non-treated cultures. Arrow represents timing of the stimulation, at least 3 cultures: no treatment, n = 7; 20 mm K⁺ alone, n = 3; MCD alone, n = 12; 20 mm K⁺ with MCD, n = 8; 20 mm K⁺ with MCD + cholesterol, n = 7. Error bars represent the standard error of the mean (s.e.m.) *P < 0.05, **P < 0.01.