Closed cranial window rodent model for investigating hemodynamic response to elevated intracranial pressure

Background:Elevated intracranial pressure(ICP)occurs in several physiological and pathological conditions,yet long-term sequellae are not common,which implies that blood flow is preserved above ischemic thresholds.Methods:This pilot study sought to confirm this hypothesis using a closed cranial window model in a rat in which ICP was elevated to 120 mmHg for 12 min,and superficial cortical perfusion was measured by laser Doppler flowmetry and laser speckle flowmetry.Results:Following a transient increase,cortical blood flow decreased to between 25%and 75%of baseline.These levels correspond to disrupted metabolism and decreased protein synthesis but did not exceed thresholds for electrical signaling or membrane integrity.This may partially explain how some episodes of elevated ICP remain benign.Conclusion:The closed cranial window model provides a platform for prospective study of physiologic responses to artificially elevated ICP during neurosurgery to promote hemostasis.

Waggle needling Yanglingquan(GB34) enhances cerebral blood flow and ameliorates condition of spastic paresis in rats with middle cerebral artery occlusion induced by surgical nylon suture

OBJECTIVE:To evaluate the therapeutic efficacy and the influence on cerebral blood supply of waggle needling Yanglingquan(GB34) on spastic paresis(SP) rats after middle cerebral artery occlusion(MCAO) induced and investigate its mechanism of relieving neurobehavior deficiency.METHODS:SP rat model was produced by permanent MCAO.Rats were divided into five groups:blank control group(Control),sham operation group(Sham),model group(Model),waggle needling group(WN) and perpendicular needling group(PN).SP rats were treated with acupuncture from day 3 after MCAO,once a day for 6 d.The modified neurological severity score(m NSS) and modified Ashworth scale(MAS) were conducted on days 0,1,3,5,7 and 9.Cerebral blood flow(CBF) in ischemic cortex was measured by laser speckle imaging 5 min pre ischemia,5 min post ischemia,and after intervention on day 9.All rats were sacrificed at day 9 and the protein and m RNA expressions of γ2 subunit of the γ-aminobutyric acid receptor A(GABAAγ2) and K+-Cl-cotransporter 2(KCC2) in the ischemic cortex and lumber enlargement was measured by Western blotting and real-time quantitative polymerase chain reaction.RESULTS:Both Control and Sham groups showed no changes in m NSS and MAS scores and in the regional CBF.Compared with Model group,both WN and PN treatments significantly ameliorated neurological deficit(P < 0.01),decreased muscle tone(P < 0.05),and enhanced CBF(P < 0.001) in SP rats;moreover,WN showed superior effects than PN(P < 0.001).In line with the improvement in neurobehavior,acupuncture interventions up-regulated the expressions of GABAAγ2 and KCC2 in the ischemic cortex as well as lumber enlargement(P < 0.01) in SP rats,and those changes were more obvious in WN(P < 0.05).CONCLUSIONS:Acupuncture at Yanglingquan(GB34) enhanced cerebral blood flow and ameliorated SP in permanent MCAO rats,while waggle needling was superior to regular perpendicular needling.Waggle needling Yanglingquan(GB34) would be a potential complementary therapy for SP.