m-Chlorophenylpiperazine enhances neophobic and anxious behaviour in mice

1-(3-Chlorophenyl)piperazine (mCPP) reduced novelty-seeking behaviour as well as the number of rears in mice confronted with a free exploratory test. Moreover, mCPP was found to decrease the time spent by mice in the lit box and the number of transitions in a two-box light/dark choice situation validated for the detection of anxiolytic or anxiogenic drugs. These results suggest that mCPP enhances emotional responses towards novel and aversive places. Since mCPP has been reported as a 5-HT1C receptor agonist, it can be hypothesized that increased activity of serotonin may play a role in regulating certain forms of emotional behaviour in animals.