| BackgroundParkinson’s disease(PD)is a neurodegenerative disorder characterized clinically by bradykinesia,tremor,rigidity and gait abnormalities.The pathogenesis of PD is very complex and has not been completely clear,so there is still no an effective method and medicine to treat this disease.Current researchs has shown that enriched environment(EE)can enhance neuroplasticity and may play a part in rehabilitation to this disease.But the mechanism is unclear.It has been found that miR-133 b is specifically expressed in dopaminergic neural cells in the midbrain.MiR-133 b plays an important role in the function and survival of dopaminergic neural cells.The aim of this study was to investigate what will happen to the miR-133 b in PD rat models after exposure to EE.Part One: Enriched environment promotes dopaminergic neuronal and behavioral recovery in Parkinsonian rats.ObjectiveTo observe the change of rats behavior and dopaminergic neuron expression in the nigrostriatal dopaminergic system influenced by enriched environment in an established Parkinson’s disease(PD)model,so as to study the mechanism of the method.MethodAfter the modeling surgeries,established male Wistar rats were randomly assigned into 2 groups: an enriched environment intervene group(group PD + EE),a standard environment intervene group(group PD + SE).Besides,2 groups served as the sham operation groups: exposure to Enriched environment(group sham + EE)and standard environment(group sham + SE)respectively.Rats received different interventions for 6 weeks.After that period,we ran some behavior tests and dopaminergic neuron detection through immunohistochemistry(IHC)towards all the animals.Result1.All sham-group animals successfully performed the beam-walking performance test without making any errors during walking.However,a increased incidence of slips was observed in the PD moldel rats,exposed to SE(Z=-3.614,p<0.01),by contrast,it was lower increased in the PD moldel group,exposed to EE(Z=-2.763,p<0.05).2.The TH positive neurons in lesion side of substantia nigra-striatum system in 6-OHDA groups was significantly lower than that in vehicle-treated rats(Z=-2.882,p<0.01).When the lesioned rats exposed to EE,the TH immunoreactive positive cells in the lesion side were increased compared with the PD rats exposed to SE(Z=-2.722,p<0.01).ConclusionEE can increase dopaminergic neurons of substantia nigra-striatum system in PD rats.Part Two: The effects of enriched environment intervention on expression of miR-133 b in midbrain of the rat model of Parkinson’s disease.ObjectiveTo observe the effects in miR-133 b of rats,so as to get some information about how the enriched environment treats Parkinson’s disease(PD).MethodWe used 6-OHDA to build a rat unilateral model.The Parkinsonian rats were randomly assigned into 2 groups: a group exposed in enriched environment(group P1)and a group exposed in standard environment(group P2).Besides,we used vehicle to build sham operation group(S)as well.Rats from group S randomly assigned into 2 groups: an enriched environment intervene group(group S1),a standard environment intervene group(group S2).All the animals were killed after the intervention and midbrain was selected,in which we then detected miR-133 b through Real-time fluorescence quantitative(q RT-PCR).ResultMiR-133 b in lesion side of substantia nigra in 6-OHDA groups was higher than that in vehicle-treated rats(t=23.093,p<0.01).When the lesioned rats exposed to EE,miR-133 b in the lesion side were decreased compared with the PD rats exposed to SE(t=7.442,p<0.01).ConclusionEnriched environment may inhibit the expression of miR-133 b,which may be the mechanism of the rehabilitation of dopaminergic neurons. |
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