3,31-Iminodipropionitrile (IDPN) has been reported to disrupt learning and memory in rats. he present work addressed the effects of IDPN on tasks requiring the use of spatial information. eparate groups of male rats received LDPN (0-400 mg/kg, IP) for three consecutive days and were tested in a passive avoidance (PA) task, the Morris water maze (MWM) , and three radial arm maze (RAM) tasks (acquisition, steady-state performance, and repeated acquisition) . IDPN increased step-through PA latencies at @100 mg/kg/day, but not at 100, or 150 mg/kg/day. n the MWM rats given 175 or 200 mg/kg/day of IDPN displayed a severe swimming deficit; no performance deficits were observed at 100, 125, or 150 mg/kg/day. n both the acquisition and the steady-state RAM tasks, IDPN (400 mg/kg/day) induced an increase in both choice errors and perseverative errors. n the RAM repeated acquisition paradigm, IDPN (200 mg/kg/day) induced performance deficits that included a decreased rate of learning within sessions. he present data show that IDPN disrupts performance of tasks requiring spatial learning and memory, and indicate that these deficits can be in part caused by an acquisition deficit.