Research About The Change Of The Firing Characteristic Of PF And M1and Their Relationship In Rat Of Parkinson’s Disease

Parkinson’s Disease (Parkinson ’s diseases, PD) is caused by the loss ofdopaminergic neurons in the nigra of midbrain, which results in the abnormal signaltransmission in the cortex-basal ganglia–thalamus-cortex and leads to various kindsof movement disorders. In this study,6-hydroxydopamine(6-OHDA) was used toestablish model rats with Parkinson’s disease(PD).The micro-electrode array wasimplanted into the rats’ brain and the Spike and the Local Field Potential（LFP）ofParafascicular nucleus and Primary motor cortex of the rats in awake and moving statewere recorded by using the multi-channel recording technology in vivo.With neural signalanalysis software(Offline-Sorter,Neuroexplorer,Matlab),the electrophysiologicalcharacteristics of PF and M1neurons with Parkinson’s Disease and the relationshipbetween them were analyzed. And the change of dopaminergic neurons of the substantianigra was observed by immunohistochemistry technology, which was aimed at providingtheoretical basis in exploring the pathogenesis of PD and finding more effectivelytherapeutic strategies.Results: According to the peak potential features, there are two types of neurons inPF. In a lucid and stationary state, significant changes of PF Spike potential in PD ratswere observed in the firing pattern.The changed feature of LFPs in PF of PD rats wasthe decrease in0.7~12Hz frequency and the increase in12~35Hz and35~70Hz.Compared with the normal rats, the discharge rate of two types neurons of PF in PD ratsdecreased significantly and the firing pattern changed as well. The characteristic of LFP inPF of PD rats is the significant decrease in0.7~12Hz, and a significant rise in12~35Hz,35~70Hz.Neurons in M1could be divided into two categories, including Interneurons and pyramidal neurons. In a stationary state, the discharge rate of pyramidal neurons in thePD rats significantly reduced (4.8-4.2). The LFPs signals at0.7~12Hz reduced whilethose at12~35Hz、35~70Hz incresed in experiment group compared with the controlgroup (P<0.01).The cross-Correlation between the synchronous signals of M1and PF understationary state was analysed by Matlab software, showing that the synchronicity of LFPsin M1and PF increased in PD rats. The correlation coefficient was much more in12~35Hz.The mean phase coherence increased significantly in0.7~12Hz and12~35HZ.Conclusions: The spikes and LFPs all changed in PF and M1nuclei in PD rats, andthe correlation of them increased, through which we could speculate that there was adirect link between PF and M1.PF could be considered as a target of deep brainstimulation, which would provide effective theoretical support for the treatment of PD.