effect of coadministeration of no and morphine in ca3 of hippocampus on learning and spatial memory in morphine dependent male rats

abstract: ِintroduction: the effect of morphine dependency on learning and spatial memory is controversial. so in this study effect of co-administeration of nitric oxide (no) and morphine in ca3 of hippocampus on learning and spatial memory in morphine dependent rats was investigated. methods: after anaesthetization of male rats, cannulae implanted bilaterally in ca3 of hippocampus. after recovery period (7 days), morphine dependency induced then animals divided in 6 groups that received 1μl saline (sham), l-arginine, l-name and morphine individually and l-arginine with morphine or l-name with morphine individually. morphine dependency was induced by subcutaneous injection of morphine(10mg/kg first day and 20mg/kg for four days). last dose of morphine(20mg/kg) was injected daily to maintain morphine dependency during test period (5 days) in morris water maze results: results showed that l-name decreased learning in morphine dependent rats although was ineffective on retention of memory. morphine did not affect learning and spatial memory. co-administeration of l-arginine and morphine not only improved the effect of morphine on learning and memory but also promote the effect of l-arginine on learning and spatial memory. conclusion: thus co-administeration of no and morphine in morphine dependent rats can improve learning and spatial memory differently from using them individually.