COMBINED PCPA AND MUSCARINIC ANTAGONIST TREATMENT PRODUCES A DEFICIT IN RAT WATER MAZE ACQUISITION

A 3-day treatment with p-chlorophenylalanine (pCPA, 100 mg/kg/day) pro duced a significant decrease (63-89%) in 5-HT levels in both the hippo campus and the cortex of rats, while noradrenaline, adrenaline, and do pamine levels were unaffected. Treatment with pCPA alone did not affec t the acquisition of a spatial learning task in the water maze. Treatm ent with low doses of either scopolamine (0.25 mg/kg) or atropine (10 mg/kg) was also insufficient to cause a significant impairment of wate r maze acquisition. However, a combined treatment of a 3-day pCPA regi men with the low dose of atropine or scopolamine produced a significan t deficit in the acquisition of a water maze task.