Modulation of the striato-pallidal pathway by adenosine A2a receptors depends on dopaminergic striatal input.

The modulation of the striato-pallidal pathway by presynaptic adenosine A2a and dopamine D2 receptors has gained attention in the study of Parkinson's disease. Here, we analyzed the effect of presynaptic A2a receptors in the spiking activity of globus pallidus (GP) neurons recorded during electrical stimulation of the striato-pallidal pathway, in both sham and ipsilaterally dopamine-denervated rats. We found that intrapallidal blockade of A2a by 100 pMol KF-17383 in sham and lesioned rats did not modify the spiking rate of GP neurons.