ABSTRACT
Objective:To explore the effect of functional electrical stimulation on cognition and on the expression of the brain-derived neurotrophic factor (BDNF), synaptophysin (SYN) and microtubule-associated protein 2 (MAP2) using a rat model of vascular dementia.Methods:Ninety pathogen-free male Wistar rats were randomly divided into a sham operation group, a placebo stimulation group and an electrical stimulation group. Both the placebo and electrical stimulation groups underwent bilateral occlusion of the common carotid artery to establish a model of vascular dementia. In the sham operation group the arteries were exposed without occlusion. Each group was then sub-divided into 3, 7 and 14 days subgroups with 10 rats in each subgroup. Beginning seven days after the surgery, the rats in the electrical stimulation group were given 30-minutes of stimulation every day while those in the sham operation group and the placebo stimulation group were given false electrical stimulation. After 3, 7 or 14 days the rats′ cognitive functioning was quantified using the Morris water maze test. The rats were then sacrificed and the expression of BDNF mRNA was measured using in situ hybridization. MAP2 and SYN levels were quantified immunohistochemically.Results:After 14 days the average latency in the placebo stimulation group was significantly longer than in the other groups. On the sixth day the average time in the target zone among the placebo stimulation group was significantly shorter than the other two groups′ averages. After only 3 days of simulation, the average expression of BDNF mRNA in the CA1 area of the hippocampus was significantly lower in the placebo stimulation group than among the others. After 7 days of stimulation the placebo group′s average was significantly lower than that of the sham operation group. The average expression of MAP2 had decreased significantly in the placebo stimulation group compared with the other two groups after 7 and 14 days of simulation. After 7 days the average expression of SYN in the placebo stimulation group was significantly lower than in the sham operation group, and after 14 days it was significantly lower than in the other two groups.Conclusions:Functional electrical stimulation may improve learning and memory in rats modelling vascular dementia through increasing BDNF, SYN and MAP2 expression levels.
ABSTRACT
Objective To investigate the effect of transcranial direct current stimulation (tDCS) on the amplitude of low-frequency fluctuation (ALFF) of the resting brain function network in patients in a minimal conscious state (MCS) so as to explore the mechanism.Methods Eleven MCS patients were selected.Among them,there were 9 males and 2 females,10 with cerebral trauma and 1 with cerebral hemorrhage,with an average age of (37.3±8.4) and an average course of disease of (3.4±0.1) months.All subjects were given a resting-state functional magnetic resonance imaging (rs-fMRI) assessment prior to the single tDCS treatment,followed by a 20-minute single sham tDCS treatment at a time.After single-sham stimulation,a second time rs-fMRI assessment test will be conducted,followed by a real tDCS treatment for 20 minutes.Eventually,a third time rs-fMRI assessment test will be implemented.Results No significant statistical difference was shown in terms of all the parameters after single shamtDCS as compared to those before the treatment (P＞0.05).After single real-tDCS,no significant change was observed with CRS-R score,ALFF of default network (left anterior wedge),the frontal-parietal network (left fróntal lobe,right superior gyms),sensory motor network (left auxiliary motor area),subcortical network (right thalamus,bilateral caudate nuclei) was significantly higher than that before treatment,while the ALFF of the frontal network (frontal lobe) and auditory network (bilateral temporal lobes) was significantly decreased (P＜0.05).After single real-tDCS,the ALFF of default network (right frontal lobe) was significantly enhanced compared to that after single sham-tDCS (P＜0.05),while that of the salient network (left insula) and sensorimotor network (right central frontal) was significantly decreased (P＜0.05).Conclusion The enhancement of ALFF activity in the resting state brain function network is a possible neural mechanism for tDCS to promote the recovery of consciousness level in pa tients with minimal conscious state.
ABSTRACT
Objective To study the effects of different types of exercise training on learning and memory, as well as on the expression of synaptophysin (SYP) and on postsynaptic density protein 95 (PSD-95) in rats in which a model of vascular dementia had been created.Methods Forty male Wistar rats were divided randomly into a voluntary exercise group (V-EX) , a forced exercise group (F-EX) , an involuntary exercise group (I-EX) , a vascular dementia group (VD) and a sham-operation group (Sham) , with 8 rats in each group.Two-vessel occlusion (2-VO) of the arteria carotis communis was used to create a model of vascular dementia in all of the rats except those in the sham-operation group.Beginning one week after the surgery, the V-Ex rats were free to run in a running wheel.The F-EX rats were forced to run 270 m a day in an electric wheel.The I-EX rats were stimulated to imitate the gait pattern of their forelimbs running at 9 m/min three times a day for l0 minutes each time.No special training was given to the rats in the other 2 groups.Three weeks after the surgery, their learning and memory were tested using a novel object recognition test.Immediately after the test, their prefrontal cortex was sampled and the expression of SYP and PSD-95 was detected using western blotting.Results The average novel object recognition indices of the rats in the V-EX, F-EX and I-EX groups were all significantly higher than that of the VD group.Average PSD-95 expression was also significandy higher than in the VD group.Conclusion Exercise, whether voluntary, forced or induced by functional electrical stimulation can improve learning and memory in vascular dementia, at least in rats.The mechanism is possibly that the training can increase the expression of PSD-95 in the prefrontal cortex, though not SYP.
ABSTRACT
Objective To investigate whether functional electrical stimulation (FES) can improve the expression of proteins in the NMDAR1-pGLuR1 pathway so as to promote the recovery of motor function and sensation after stroke.Methods Eighty-one Wistar rats were used to make a photochemical brain model of local ischemia.Rats were randomly assigned into a sham, placebo stimulation or FES group.Rats in the placebo and FES groups had local ischemia induced in the M1 zone of the brain using the photosensitive dye Bengal rose.It was administered intravenously and a laser beam was then stereotactically positioned on the skull.The rats in the FES groups were stimulated for 30 minutes (10 minutes on, 10 minutes off, then 10 minutes on).The placebo group's treatment was similar, but without the electric current.The rats in the sham group received no intervention.The cylinder test and the adhesive-removal test were used to test the rats' motor function and sensation before the operation and before they were sacrificed.Cohorts were sacrificed after 3, 7 and 14 days of intervention.NMDA receptor and AMPA receptor were detected in the peri-ischemic cortex using western blotting.Results After 7 and 14 days the index of forelimb motor function in the cylinder test of the FES group was significantly better than that of the placebo group.The average adhesive-removal time of the FES group was also significantly faster compared with the placebo group.After 7 days the average expression of NMDAR1 in the FES group was significantly higher than in the placebo group.The average expression of GluR1 and pGluR1 in the FES group was significantly higher than in the placebo group after 14 days.Conclusion Functional electrical stimulation can improve motor function after ischemia through the NMDARAMPAR signal pathway, at least in rats.
ABSTRACT
Objective To observe the effect of electroacupuncture(EA) on the hippocampal expression of GluA1,pGluA1,CaMK Ⅱ and pCaMK Ⅱ in rats with vascular dementia(VD),so as to find out the underlying mo lecular mechanisms of EA in treating VD.Methods Thirty-two Wistar rats were randomly divided into a shamoperation group,a model group,a sham-acupuncture group,and an EA group (8 in each group).Permanent bilateral common carotid artery occlusion was performed to model vascular dementia in the model group,the shamacupuncture group and the EA group,while exposure but no occlusion of the bilateral common carotid were performed in the sham-operating group.Novel object recognition test was adopted to prove the establishment of VD rat model.All the rats were kept in an immobilization apparatus while receiving treatments.EA was applied ontoBaihui (GV20) and Zusanli (ST36) in EA group for 30 min,once daily for 7 days.Sham-acupuncture group were treated with needles inserted 0.5 mm superficially.And the sham-operation group and the model group were only immobilized.The protein expression of GluA1,pGluA1,CaMK Ⅱ and pCaMK Ⅱ in hippocampal tissue was detected by western blotting.Results The expression of GluA1 in the model group (1.216 ± 0.102) was significantly less than in the sham-operating group (1.918 ± 0.137) (P ＜ 0.05).The expression of GluA1 in the EA group (1.653 ± 0.169) was significantly higher than in the model group (1.216 ± 0.102) and in sham-acupuncture group (1.231 ±0.188) (P＜0.05).The expression of CaMKⅡ in the model group (1.516±0.392) was less than in the sham-operating group (2.187 ± 0.231) (P ＜ 0.05).The expression of CaMK Ⅱ in the EA group (2.733 ±0.387) was significantly higher than in the model group (1.516 ±0.392) and sham-acupuncture group (1.493 ±0.205) (P＜0.05).The expression ofpGluA1 in the model group (1.502 ±0.419) was less than in the sham-operating group (2.253 ± 0.244) (P ＜ 0.05).The expression of pGluA1 in the EA group (2.382 ± 0.308) was significantly higher than in the model group (1.502 ± 0.419) and the sham-acupuncture group (1.498 ± 0.223) (P ＜ 0.05).The expression of pCaMK Ⅱ in the model group (0.394 ± 0.227) was less than in the sham-operating group (0.667 ±0.175) (P＜0.05).The expression ofpCaMKⅡ in the EA group (1.189± 0.346) was significantly higher than in the model group (0.394 ± 0.227) and the sham-acupuncture group (0.408 ± 0.231) (P ＜ 0.05).Conclusion EA can enhance the protein expression and phosporylation of GluA1 and CaMK Ⅱ,causing silent synapses transforming into functional synapses,and consequently,long term potentiation was facilitated and cognitive impairment was improved by EA.