Amphetamine disrupts both working and reference memories of rats trained in a radial maze.
To assess the effects of amphetamine on working and reference memory rats were trained on a 12-arm radial maze with six arms baited and six arms unbaited until stable performance was achieved. Administration of 2.0 mg/kg d-amphetamine sulfate increased both working and reference memory errors, but only if a 5-min delay was imposed after three successful choices. With no delay this dose had no reliable effect on either working or reference memory. Lower doses (0.5 or 1.0 mg/kg) were ineffective even when a delay was imposed during the test. We suggest that amphetamine heightens arousal, which disrupts accurate retention when the rat's attention to the relevant cues is interrupted, as during a brief delay. Alternative explanations are discussed.
D000818:Animals; D001143:Arousal / Q000187:drug effects; D003913:Dextroamphetamine / Q000494:pharmacology*; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects*; D009949:Orientation / Q000187:drug effects*; D051381:Rats; D012153:Retention, Psychology / Q000187:drug effects*
D003913:Dextroamphetamine