Effect of propofol on first spike latency of rat inferior colliculus neurons / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of propofol on first spike latency (FSL) of inferior colliculus neurons and explore the electrophysiological mechanisms underlying the propofol-induced loss of heating.Methods Forty-three SD rats of both sexes weighing 200-250 g were used in this study.FSL was recorded with glass recording micro-electrode inserted in inferior colliculus.Propofol 100 mg/kg was administered intrapefitoneally.FSL was recorded before and every t0 min after propofol administration when sound intensity was between 90 dB SPL and 10 dB SPL before threshold.First-order exponential function was used to fit FSL-sound intensity curve at different time points before and after propofol administration.Results The inferior colliculus neurons showed offset response in one rat.FSL extended to 0.8 ms at 10 min after propofol administration.In the remaining 42 rats,the inferior colliculus neurons responded only to the beginning part of the sound.FSL was prolonged at 10 min after propofol administration.R2 of first-order exponential function ＞ 0.95 at different time points after propofol administration ( P ＜ 0.05 ).FSL-sound intensity curve was shifted parallelly upwards after administration.Conclusion Propofol affects auditory information transmission by extending FSL of rat inferior colliculus neurons but does not change the meaning of the information encoded by FSL.