Objective To explore the effect of oxygen inhalation on auditory sensory gating P50 in healthy human brain. Methods 28 healthy male academician right-handed were included. They were divided into control group (n=12) and experiment group (n=16) according to the random numerical table, and blinded about groups. The subjects inhaled pure oxygen in the experiment group, and air in the control group through a mask for 60 min. The electroencephalograph was recorded while an auditory paired-click sensory gating test was conducted during 4 study periods: before inhalation (pre0), inhale for 20 min (Oxy20) and 50 min (Oxy50), and 30 min after inhalation (post30). The latency and amplitude (S1-S2) of auditory sensory gating P50 were calculated. Results The latencies of P50 from S1 were stable in each group (P>0.7), and the latency of Oxy50 was shorter in the experiment group than in the control group (P<0.05). The latencies from S2 were stable in each group (P>0.30), and there was no significant difference between groups in all the time points (P>0.05). The amplitudes of (S1-S2) of P50 were stable in the control group (P=0.70), and was higher on Oxy20 (P=0.04) and Oxy50 (P=0.02) than post30 in the experiment group. There was no difference between the groups in all the time points (P>0.05). Conclusion Oxygen inhalation may be helpful to shorten the active time to stimulate, and trend to enhancing the amplitude of P50.

Objective To observe the change of the latency and amplitude of auditory-evoked potential P300 after oxygen inhalation.Methods 27 healthy male academicians were included. They were divided into control group (n=12) and experiment group (n=15) according to the random numerical table, and they were blinded about groups. All subjects in the experiment group inhaled pure oxygen while air in the control group through a mask for 60 minutes. EEG was recorded when an auditory Oddball paradigm was performed during following 4 periods: before oxygen inhalation (pre0), inhale oxygen (air in control) for 20 minutes (Oxy20) and 50 minutes (Oxy50), 30 minutes after oxygen inhaled (post30). The latency and amplitude of P300 from target stimuli were calculated. Results The latency of P300 was longer at Oxy20 as (358.58±15.32) ms, Oxy50 as (353.42±9.41) ms and post30 as (354.10±10.42) ms than at pre0 as (335.91±15.40) ms in the control group (P<0.01). The latency of P300 was shorter at Oxy50 as (319.17±14.34) ms, and post30 as (318.50±13.87) ms than at pre0 as (332.98±14.63) ms in the experiment group (P<0.05). The latency was shorter in the experiment group than in the control group at Oxy20,Oxy50 and post30 (P<0.01). The amplitudes were stable in the control group (P<0.05). The amplitude was lower at post30 as (2.41±0.64) μV than at pre0 as (5.49±0.89) μV in the experiment group (P<0.05). Conclusion Oxygen inhalation shortens the latency of P300, and decreases the amplitude in the similar trend with the prolongation of oxygen inhalation.