Fig. 1: Behavioral profiles in amphetamine-sensitized mice induced by 3XAMP regimen.

a 1 mg/kg of amphetamine was administered intraperitoneally three times per day for 6 days (3XAMP) for induction of schizophrenia-relevant behaviors and a series of behavioral assessments for 21 days was performed in the amphetamine-sensitized mice (AMP). Vehicle was administered to control group (CON) as same regimen. b AMP showed mania-like behavior (longer distance traveled, much cumulative time in center zone, and more frequency in center zone) in an open field test (OFT), c stayed longer in the light region in the light–dark box test (LD), reduced immobility time in d tail suspension test (TST), and e forced swimming test (FST) compared to CON. f AMP spent much time in dummy chamber in the three chambers social interaction test (SI). g AMP showed more freezing behavior in pre-exposed group (PE), but there was no difference between CON and AMP in the non pre-exposed group (NPE). h AMP induced by the 3XAMP regimen did not show any difference compared to CON in the pre-pulse inhibition test (PPI). Mania-like behaviors initially seen after the withdrawal of amphetamines was normalized in LD (i), TSF (j), and FST (k). n = 8–10 in each group *p < 0.05, **p < 0.01 compared with the CON. LI was performed 2 times independently; n = 14–15 per CON or AMP. The data shown are mean ± standard error of the mean (SEM). *p < 0.05 compared to CON of NPE, AMP effect was significant (F_(1,27) = 7.738, p = 0.0097) on latent inhibition.