A comparison of 1-benzylpiperazine and methamphetamine in their acute effects on anxiety-related behavior of hooded rats.

Following i.p. treatment with saline, 10 or 20 mg/kg 1-benzylpiperazine, or 1 or 2 mg/kg methamphetamine, hooded rats were observed in an open field, a light-dark box and (24 h after exposure to the drugs) a Y maze with one novel and one familiar arm. Both drugs increased open-field rearing and ambulation, but only methamphetamine increased and decreased respectively occupancy of center squares and corners, while stereotyped head movements were increased by 20 mg/kg benzylpiperazine. Time spent in and entries of the light compartment of the light-dark box were decreased by benzylpiperazine but not methamphetamine, and entries of the novel Y-maze arm were decreased by methamphetamine for male rats only. Although most behavior emitted in the open field and light-dark box following treatment with methamphetamine could be ascribed to the drug's locomotor stimulant effect, increased stereotypy with the high dose probably interfered with this action for benzylpiperazine. However, both drugs may have led to some anxiety-related novelty avoidance in the Y maze. Overall, the patterns of results for the two drugs revealed more similarities than differences (with methamphetamine possibly being more effective than benzylpiperazine) and thus supported the view that, because of commonalities in their neurochemical effects, benzylpiperazine may have similar abuse and dependence risks to methamphetamine.