Pretreatment of rats with Dex at young age improved the propofol-induced impairment in spatial learning and memory ability in adult age.
Notes: P group: i.p. injected with 50 mg/kg propofol, and 40–60 min later, when the righting reflex was recovered, the procedure was repeated one more time; PD25, PD50 and PD75 groups: intraperitoneal injection with 25, 50 and 75 μg/kg Dex, and 30 min later, intervention with propofol; LPD group: intracerebroventricular injection with 25 μg/5 μL LY294002, and 30 min later, intervention with Dex and propofol; TPD group: intraperitoneal injection with 1 mg/kg TDZD-8, and 30 min later, intervention with Dex and propofol. DS1 and DS2 groups: intracerebroventricular or intraperitoneal injection with DMSO; F group: intraperitoneal injection with intralipid; L group: intracerebroventricular injection with LY294002; T group: intraperitoneal injection with TDZD-8; Dex group: intraperitoneal injection with Dex. Young rats were pretreated with Dex or another indicated compound and injected with propofol. At 9 weeks of age, the different groups of rats were trained for 4 days and tested by MWM. The escape latency time and swimming speed of individual rats were recorded. Data are expressed as the mean±SEM of each group (n=8) from three separate experiments. (A) The escape latency time. (B) The swimming speed. (C) The escape latency time on the first training day. (D) The escape latency time on the testing day. *p<0.05 versus the NS group; #p<0.05 versus the P group; ^p<0.05 versus the PD75 group; double symbols mean p<0.01.
Abbreviations: Dex, dexmedetomidine; DMSO, dimethyl sulfoxide; MWM, Morris water maze; SEM, standard error of the mean.