Experimental studies and theoretical aspects on A2A/D2 receptor interactions in a model of Parkinson's disease. Relevance for l-dopa induced dyskinesias

Dual probe microdialysis in the awake rat has been used to study the role of A2A/D2 receptor interactions in the striato-pallidal GABA pathway in a model of Parkinson Disease (PD).The A2A agonist CGS 21680 and/or the D2 like agonist quinpirole were perfused via reverse microdialysis into the DA denervated striatum and the effects on globus pallidus extracellular GABA levels were evaluated. Evidence was obtained that CGS 21680 alone in the DA denervated but not the control striatum produced a transient rise of globus pallidus GABA levels. Quinpirole perfused alone into the DA denervated striatum produced a marked…