Time domain dielectric spectroscopy of crayfish tail muscle, measured in vivo

We measured the dielectric spectra of crayfish tail muscle, in vivo, in both the time and frequency domains. We inserted a linear array of four needle electrodes (denoted 1, 2, 3 and 4) into the tail muscle. For time domain dielectric spectroscopy (TDDS), we used the MacADIOS data acquisition system to apply a voltage step of amplitude V0 and to sample the resulting voltages across electrodes 1 and 2 and also across 3 and 4 as well as the current, I, that flowed through a series resistor during polarization and depolarization. Fourier transformation of the variation of the conductance between 2 and 3 with time yielded the capacitance and conductance spectra of the muscle from about 1 kHz down to 0.1 Hz with electrode effects presumably eliminated. A Hewlett-Packard 4192A low-frequency impedance analyzer (IA) measured directly the capacitance and conductance spectra between electrodes 2 and 3 from 100 Hz to 1 MHz. The TDDS results exhibited a strong dispersion for frequencies on the order of 10 Hz that could be characterized by a KWW response (T∼0.1 s and β∼0.8). We modeled the IA results as a Cole–Cole dispersion with n=0.5.