Effects of electro-acupuncture on learning and memory and the expression of Noggin mRNA in the hippocampus of rats with chronic cerebral ischemia

Abstract

Objective To observe the effects of electro-acupuncture (EA) on learning,memory and the expression of Noggin mRNA in the hippocampus after cerebral ischemia.Methods One hundred and four male Sprague-Dawley (SD) rats were subjected to a modified form of permanent bilateral carotid artery ligation to produce a model of chronic cerebral ischemia.They were then randomly divided into a model group and an EA group,with 52 rats in each group.Each group was then subdivided into 1,2,4 and 6 weeks subgroups,with 13 rats in each subgroup.The EA group received EA administered to the Baihui (DU20) and Dazhui (BU14) acu-points; the model group received regular feeding only.The Morris water maze test was administered in both groups at 5 days before the rats were sacrificed.At the 1,2,4 and 6 week time points,6 rats were selected from each subgroup randomly and the expression of Noggin mRNA in the hippocampus was detected using RT-PCR techniques.Results The Morris water maze test showed significantly lower escape latency in the EA group at 2,4 and 6 weeks.Swimming time in the first quadrant was also significantly different at all time points.The average level of Noggin mRNA in the EA group was significantly higher than that in the model group at all of the time points.After 6 weeks,the average level of Noggin mRNA in the EA group was significantly lower than that at the other time points within the EA group.Conclusion EA can improve spatial learning and memory and elevate the expression of Noggin mRNA in the hippocampus in cases of chronic cerebral ischemia. Key words: Electro-acupuncture; Hippocampus; Learning; Memory