The effect of Crocin on scopolamine induced spatial learning and memory deficits in rats

The cholinergic system plays an important role in learning and memory. Administration of either extracts of Crocus Sativus (Saffron) or its constituent, crocin, reduced ethanol-induced memory impairment. Based on the above findings, we investigated the effect of crocin in antagonizing spatial learning and memory impairment induced by scopolamine, a cholinergic receptor antagonist, in rats by using Morris water maze (MWM). Male rats received crocin (1, 5 or 10 mg/kg, i.p.) 30 min after injection of scopolamine (0.5 mg/kg, i.p.) or saline for 6 consecutive days. Control animals received only scopolamine or saline. Spatial learning and memory parameters in the same days were tested using MWM. For this purpose, escape latency and swim distance to hidden platform were tested for four consecutive days. In probe trials, percentages of time that animals spent in target quadrant were recorded. 24 h later, visible version of MWM was performed in which escape latency to visible platform and swim speed were tested. The results indicated that administration of scopolamine impaired the formation of spatial learning and memory processes. Application of crocin in a dose-dependent manner ameliorated the effects of scopolamine. In the visible version of MWM, there was not any significant difference in spatial performance among animals in studied groups.