Objective To observe the effect of catgut embedment at"Baihui"(GV 20)

"Dazhui"(GV 14)

etc.on learning-memory ability

expression of hippocampal protein kinase C interacting protein 1(PICK 1)and glutamate receptor 2(GluR 2)proteins and level of calcium ions

so as to explore its mechanism underlying improvement of vascular cognitive impairment.Methods A total of 56 male SD rats were randomly divided into sham operation

model

catgut embedment and medication groups(n=14 in each).The chronic ischemic cognitive impairment model was established by permanent occlusion of bilateral common carotid arteries.The catgut embedment was applied to GV 20

GV 14

"Shenshu"(BL 23)and"Xuanzhong"(GB 39)

once a week

for 4 weeks.Rats of the medication group received intraperitoneal injection of monosialate tetrahexose ganglioside sodium(GM-1

0.33 mg/kg)

once daily for 4 weeks.The rats' learning-memory ability was detected by Morris water maze tasks

pathological changes of hippocampal Nissl's bodies were tested by Nissl staining.The expression levels of PICK 1 and GluR 2 proteins in the hippocampus were detected by Western bolt(WB)

and the concentration of calcium ions in the hippocampus tissue was measured by Bicinchoninic acid(BCA)assay.Results After modeling

the mean escape latencies of place navigation test were significantly increased while the crossing times of target platform quadrant of space probing test notably decreased in the model

catgut embedment and medication groups compared with their own individual pre-modeling(P<0.01).Following the treatment

the increased mean escape latencies and decreased crossing times were markedly reversed in both catgut embedment and medication groups relevant to the model group(P<0.01

P<0.05).Nissl staining showed that after modeling

a smaller amount of Nissl bodies with dispersing arrangement

reduction in cellular volume

and loss of large amount of cells with vague structure

and hyperchromatic nuclear pyknosis were found in the hippocampus tissue

which was relatively milder in both catgut embedment and medication groups.The hippocampal PICK 1 protein expression and the calcium ion concentration were obviously higher in the model group than in the sham operation group(P<0.01)

and significantly lower in both embedment and medication groups than in the model group(P<0.01

P<0.05)

while hippocampal GluR 2 protein expression was obviously lower in the model group than in the sham operation group(P<0.01)

and markedly higher in both embedment and medication groups than in the model group(P<0.05

P<0.01).No significant differences were found between the embedment and medication groups in the abovementioned indexes(P>0.05).Conclusion Catgut implantation at GV 20 etc.can effectively improve the learning-memory ability in rats with chronic ischemic cognitive impairment

which may be related to its effects in down-regulating the expression of PICK 1 and calcium ion concentration and up-regulating the expression of AMPA receptor subunit GluR 2 protein in the hippocampus.