The Effects Of Bicuculline On The Expression Of CPP And Electroencephalogram Induced By Morphine

The experiment of conditioned place preference(CPP) is the classical experimental model. CPP experiment is also widely used to study conditional behaviour.The effects of bicuculline on the expression of CPP and electroencephalogram(EEG) induced by morphine were observed based on the traditional CPP experimental model using implantable radiotelemetry,and the power spectrum of EEG was analyzed in order to find the relationship between behaviour and EEG.The rats were divided into four groups,which are saline group(1ml/kg,i.p.),morphine (5mg/kg,i.p.) group,bicucullin(0.5mg/kg,i.p.) group,bicuculline(0.5mg/kg,i.p.) break morphine(5mg/kg,i.p.) group.The CPP experimental process of the first three took turns: preliminary adaption,prior test includs behaviour and EEG,conditional traing,posterior test includes behaviour and EEG.While the forth group took turns:preliminary adaption,conditional traing,posterior test,i.p.bicucullin(0.5mg/kg,i.p.) posterior test.It was found that CPP was induce by morphine,moreover,the EEG of morphine group was different when the rats were in drug-matching box and in the drug-unmatching box;by power spectrum analysis,one hand,it was found thatγ%was sharply increased,whileβ%,a%,θ% andδ%significantly decreased in drug-matching box.And moreover,the changes ofγ%,β%, a%andθ%were broken by bicuculline,butδ%could not be broken by bicuculline.The other hand,the EEG in drug-unmatching box was changed in the opposite direction,which was thatγ%was markedly enhanced,while the a%,θ%andδ%were significantly increased,but theβ% was unchanged.The EEG power spectrum were broken by bicuculine in drug-unmatching box.The results had shown that bicuculline could break the expression of CPP and the EEG changing induced by morphine,and suggest that GABA_A receptor play an important role in the expression of CPP induced by morphine.