After-effects Of TDCS On Animal Models Of Alzheimer's Disease

Alzheimer's disease(AD)is a most common,currently incurable and irreversible senile neurodegenerative disease.With the increasing emphasis on aging,the number of patients suffering from AD will increase significantly.AD not only causes patients suffer from physical and mental health and seriously affects daily activities,but also greatly increases the cost of treatment and care,adding a heavy economic burden to patient's family and even society.At present,mainstream drug treatment has little effects in delaying the development of AD,let alone cure AD.In other words,AD treatment encounters a bottleneck.As an important potential prevention and treatment approach of AD,transcranial direct current stimulation(tDCS)shows remarkable effects on learning & memory improving,protecting neurons,and inhibiting inflammation.However,the study of tDCS is in its infancy.The unclear action mechanism seriously hampered the tDCS clinical application in AD prevention and treatment.The effects of tDCS persist not only during the stimulation,but also after the end of stimulation(after-effects)that can be maintained for a period of time.Here,after-effects of repetitive anodal tDCS on animal models of AD were investigated.After completing the tDCS stimulator which is suitable for animal experiments,researches on the following two aspects were conducted:The duration of After-effects of tDCS on AD rats were investigated first.In the experiment,the ?-Amyloid(A?)was injected into the rat's bilateral hippocampus to product the AD rat,and anodal tDCS of 10 sessions was applied in AD rats.After the end of the stimulation,the Morris water maze(MWM)was conducted monthly in the three groups: the AD group,the sham group and the stimulation group.Histological analyses of the hippocampus were conducted when there was no obvious difference between the AD group and the stimulation group.The three MWM were carried out in the study and the hippocampal choline acetyltransferase(ChAT)and glia-fibrillary-acidic protein(GFAP)immunohistochemical analyses were finished after 2 moths in the end of the stimulation.Results showed there were still significant differences in the other hippocampal sub-regions except DG.The study revealed that repetitive anodal tDCS can improve cognitive function and memory performance,and the effective long-term after-effects,although have gradually weakening trend,can persist for at least 2 months.In order to futher explore the mechanism of after-effects of tDCS on AD,a pre-experiment was conduted.APP/PS1 double transgenic AD mice,which can naturally mimic the course of AD,were selected in the pre-test to explore the after-effects of tDCS wether can influence the level of the A? wich is the key biomarker of AD.In the pre-test,6-moth-old AD mice received the 10 essions of anodal tDCS,and then the A??the ChAT and the GFAP immunohistochemical analyses were respectively compeleted.Consistent with the conclusion of the after-effects of tDCS on AD rats,after-effects of repetitive anodal tDCS on AD mice also played the important role in protecting neurons,and inhibiting inflammation.Moreover,in comparison with the model group,the A? plaques in the stimulation group had a tendency to decrease.And more repeated experiments were needed to confirm the conclusion of the A? plaques.