Effects of NMDA receptor antagonists on probability discounting depend on the order of probability presentation.

摘要: Abstract Risky decision making can be measured using a probability-discounting procedure, in which animals choose between small, certain reinforcer and large, uncertain reinforcer. Recent evidence has identified glutamate as mediator of risky making, blocking the N -methyl- d -aspartate (NMDA) receptor with MK-801 increases preference for Because order probabilities associated large modulate effects drugs on choice, current study determined if NMDA ligands alter probability discounting ascending descending schedules. Sixteen rats were trained procedure odds against obtaining increased (n = 8) or decreased across blocks trials. Following behavioral training, received treatments (uncompetitive antagonist; 0, 0.003, 0.01, 0.03 mg/kg), ketamine 1.0, 5.0, 10.0 mg/kg), ifenprodil (NR2B-selective non-competitive 3.0, 10.0 mg/kg). Results showed was steeper (indicating risk aversion) an schedule relative to schedule. Furthermore, MK-801, ketamine, dependent used. Specifically, highest dose each drug taking schedule, but only (0.03 mg/kg) These results show that presentation modulates making.