Exposure to benzylpiperazine (BZP) in adolescent rats: Adulthood changes in anxiety-like behaviour.

Increasingly, individuals in New Zealand are taking "herbal highs" with little knowledge of their possible long-term effects. Benzylpiperazine (BZP) is the predominant base drug in most herbal highs. The limited research into BZP has suggested that it produces similar effects to amphetamine, but could be 10 times less potent. There are to date, however, no long-term behavioural studies of BZP exposure. This study therefore, investigated effects of BZP exposure in adolescent male and female rats on subsequent measures of anxiety-like behaviours in adulthood. One group of experimental animals was treated daily with BZP, whereas another group received the same total amount of drug via a four day "binge" regime. The results suggested that, when observed in a Y-maze, social interaction test and a light/dark emergence test, BZP-treated rats were more anxious than control animals. In the Y-maze, male controls were more active than female controls, but BZP-treated females were more active than treated males. Results of this interaction indicate that the male rats may have been more affected by the administration of BZP during adolescence than females. Additionally, rats given the binge dose regime showed significantly increased anxiety in the Y-maze relative to the daily-exposed or control rats'. This suggests that larger quantities of BZP over a shorter time frame produce more detrimental effects than smaller quantities of BZP over a longer time frame. Overall, it would appear that the administration of BZP to adolescent animals produces behavioural changes in emotionality that are detectable in adulthood