Effect of Propofol on Brain Electrical Activity in Cat Motor Cortex

Objectives To investigate the transformation of field potential and neuronal action potential in the motor cortex of cat introduced by propofol. Methods Three healthy adult cats (2 female, 1male) weighted 3.5~5.0kg, were enrolled in this study. The animals received intravenous injection propofol 5mg/kg, then the field potentials of 0~25Hz and the action potentials of 500-4kHz were extracted respectively. Spectral edge frequency (SEF) of field potentials were calculated and Short-time Fourier transform (STFT) was applied to determine the frequency components of field potentials as it changes over time. Simultaneously, the firing rate of action potential was calculated during the whole process. Subsequently, time-phase relationship of field potential and action potential was studied. Result Spectral edge frequency decreased in the administration of propofol, then returned to pre-operation level 60 min later; the firing of cortical neuron was suppression after propofol injection and cortical action potentials were re-emergence 75min later. Conclusion propofol can cause reversible changes in the motor cortex of cat. The recovery time of field potential was less than the time of action potential.