Effects of theophylline in p-chlorophenylalanine-treated mice in a light/dark test.

The effects of theophylline were examined in a light/dark test in p-chlorophenylalanine (PCPA)-treated mice to investigate serotonergic contribution to its effects. Three consecutive treatments with PCPA (200 mg/kg once daily) barely affected parameters in the light/ dark test. In vehicle- and PCPA-treated mice, theophylline (100 mg/kg) significantly decreased time spent in the light zone, which suggested its anxiogenic-like activity. In...