Effect Of Electrical Stimulation Of The Entopeduncular Nucleus On The Neuronal Activities Of Pedunculopontine Nucleus In PD Rats

ObjectiveTo investigate the effects of different frequency entopeduncular nucleus(EP)stimulation and microiontophoretical administration of Glu, GABA, MK-801andBIC on the spontaneous firing rate of the PPN neurons in rats of parkinson’sdisease (PD) model. To further the types of neuroreceptors of PPN neurons, theprinciple of EP deep brain stimulation to treat PD and to provide experimentalevidence for the functional neurosurgical therapy of parkinson’s disease.MethodTo record the spontaneous firings of the PPN neurons using one or sevenpipe glass microelectrodes, and to observe respectively the effects of theelectrical stimulation of EP and the effects of Glu，GABA and their antagonistsadministrated microiontophoretically on the firing rate of the PPN in PD rats.ResultThe spontaneous discharge rate of the PPN neurones in PD rats wasobvious higher than in control rats and the spontaneous discharges of the PPNneurons trended to more irregularly and bursty. Low frequency（5-10Hz）electrical stimulation of EP had no obvious influence on the spontaneousdischarges of PPN neurons, while the high frequency stimulation (HFS) of EPcould mainly descrease the spontaneous discharges of the majority of PPNneurons. The inhibiting effect of100Hz stimulation was maximal. Gluadministrated microiontophoretically could increase the spontaneous firingactivities, which could be blocked by MK-801; GABA would decrease the neuronal acivities of most PPN neurons. BIC administratedmicroiontophoretically could respectively suppress the effect of GABA andEP-HFS on the PPN neurones in PD rats.ConclusionsThe spontaneous discharge rate of the PPN neurones in PD rats wasobvious higher and the spontaneous discharge of the PPN neurons trended tomore irregularly and bursty. HFS-EP could descrease the spontaneousdischarges of the majority of PPN neurons. The inhibiting effect of100Hzstimulation was the most obvious. Glu administrated microiontophoreticallycould increase the spontaneous firing activities and GABA would decrease theneuronal acivities of most PPN neurons. BIC could respectively suppress theeffect of GABA and EP-HFS on the PPN neurones in PD rats, suggesting thathigh frequency stimulation of EP improves the symptoms of PD partly throughthe change of activity of PPN neurons.