Abstract: AIM: To investigate the effects and possible mechanism of Rhodiola Rosea (RR) on learning and memory in rats after sleep deprivation. METHODS: Sleep deprivation was induced by the flower pot technique. Half of each group went through Y-maze test and were detected for superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in hippocampus and frontal lobe. The other half were detected for expression ofcholineacetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP) in hippocampus by immunohistochemistry technique. RESULTS: In Y-maze test, total reaction time (TRT) was shorter and error numbers (EN) were less (P<0.05) in RR group than in model group. SOD activity in both hippocampus and frontal lobe was higher (P<0.05) and MDA content in hippocampus was lower (P<0.05) in RR group than in model group. In immunohistochemistry detection, ChAT expression positive cells were in larger quantity and colored at darker profile with clearer outline and more regular arrangement (P<0.05) in RR group than in model group. GFAP expression positive cells were in smaller quantity and colored at lighter mode with smaller volume and fewer and shorter neurite and branches (P<0.05) in RR group than those in model group. CONCLUSION: RR can protect brain from oxidative damage and neuron injury as well as alleviate the impairment on learning and memory capability caused by sleep deprivation.

Key words: Rhodiola rosea, Sleep deprivation, Learning and memory, Hippocampus, Frontal lobe, Superoxide dismutase, Malonaldehyde, Choline acetyl transferase, Glial fibrillary acidic protein