Fig. 2. Power spectra obtained from experiments with (A) NaCl Ringer as the mucosal and serosal bathing solutions, (B) NaCl Ringer as the serosal solution and KCl Ringer as the mucosal solution and (C) NaCl Ringer as the mucosal solution and KCl Ringer as the serosal solution. Note the presence of two Lorentzian components in C. The spectra from A and B are from sequential treatments of the same preparation as depicted in Fig. 1. S_f, spectral density. The arrows on the spectra indicate the range of data points selected for the computer fit of the spectra using equation 1.