Objective      To establish a new rat model of posttraumatic stress disorder (PTSD) with compound stress stimulations.       Methods      Thirty male adult SD rats were randomly divided into 3 groups: a normal group

a single-prolonged stress (SPS) group and a compound stress group (CS) (n=10). The CS rats were given compound stress stimulations of restraint

electric shock and exhaustive swimming to establish the PTSD rat model. The Morris water maze test

elevated plus maze (EPM) test and open-field test were used to examine the behavioral changes of the rats after 14 d.       Results      The rats of the CS group showed significant PTSD-like behavioral changes

lower locomotor activity

more anxiety-like behavior and poorer spatial cognitive ability compared with the normal group and SPS group on the 14th day after stimulation. (1) The scale of rat response to capture significantly increased in the CS group (1.4±1.0) compared with that in the normal group and the SPS group (P0.05

P0.01). (2) The open-field tests revealed that the times of crossing (27.80±5.55) and rearing (9.00±2.49) of the CS group significantly decreased compared with those of the normal group and the SPS group (P0.01

P0.05)

but there was no significant difference of grooming times among the three groups. (3) The data of EPM test showed that the ratio of open arm entry (OE%) (27.50±1.35)

the ratio of open arm time (OT%) (29.62±3.23) and open arm entry + close arm entry (OE+CE) (8.60±3.63) significantly decreased in the CS group compared with those in the normal group and the SPS group (P0.05). However

the times of head-dipping and rearing showed no significant differences among the three groups. (4) The Morris water maze test showed that the escape latency had no significant difference among three groups on the first and the second day

but the escape latency in the CS group (35.67±5.13

25.09±3.55) was significantly longer than that of the normal group and SPS group on the third and the fourth day (P0.01

P0.05). In the spatial probe test

the times of entering target quadrant and crossing hidden platform significantly decreased in the CS group (5.80±2.34

3.10±1.79) compared with those in the normal group and SPS group (P0.01

P0.05).       Conclusions      The rat behavior test confirms that compound stress is a simple and effective method for the establishment of PTSD model in rats.