Gamma band oscillation (GBO) and sensory gating (SG) are associated with many cognitive functions.Ketamine induces deficits of GBO and SG in the prefrontal cortex (PFC).However,the time-courses of the effects of different doses of ketamine on GBO power and SG are poorly understood.Studies have indicated that GBO power and SG have a common substrate for their generation and abnormalities.In this study,we found that (1) ketamine administration increased GBO power in the PFC in rats differently in the low-and high-dose groups;(2) auditory SG was significantly lower than baseline in the 30 mg/kg and 60 mg/kg groups,but not in the 15 mg/kg and 120 mg/kg groups;and (3) changes in SG and basal GBO power were significantly correlated in awake rats.These results indicate a relationship between mechanisms underlying auditory SG and GBO power.