Putrescine decreases exploration of a black and white maze

The effect of putrescine and cyclohexylamine on rat cortical polyamine concentration and on behavior in a black and white maze was studied. The levels of polyamines in brain cortex were determined 15 min, 2, 4, and 6 hours after injection of putrescine (200 or 400 mg/kg) or cyclohexylamine (380 mg/kg). Putrescine concentration increased 6-fold 15 min after injection of putrescine followed by a decline during the next 6 hours. Cyclohexylamine increased putrescine concentration doubling it 4 hours after injection. Spermidine and spermine concentrations did not change after either putrescine or cyclohexylamine injection. Behavior was studied in the Greek cross maze which provides the choice to enter either white or black compartments. Putrescine 200 mg/kg decreased entries into white but not black compartments, while putrescine 400 mg/kg decreased entries into both. The effect of cyclohexylamine was similar to putrescine 400 mg/kg. The behavioral effect of each treatment was independent of the time between injection and testing for up to 6 hours, while the levels of putrescine changed during the same period. Therefore, behavior was not directly related to total cortical putrescine.