Functional neuroanatomy of the basal ganglia as studied by dual-probe microdialysis

Dual probe microdialysis was employed in intact rat brain to investigate the effect of intrastriatal perfusion with selective dopamine D₁ and D₂ receptor agonists and with c-fos antisense oligonucleotide on (a) local GABA release in the striatum; (b) the internal segment of the globus pallidus and the substantia nigra pars reticulata, which is the output site of the strionigral GABA pathway; and (c) the external segment of the globus pallidus, which is the output site of the striopallidal GABA pathway. The data provide functional in vivo evidence for a selective dopamine D₁ receptor-mediated activation of the direct strionigral GABA pathway and a selective dopamine D₂ receptor inhibition of the indirect striopallidal GABA pathway and provides a neuronal substrate for parallel processing in the basal ganglia regulation of motor function. Taken together, these findings offer new therapeutic strategies for the treatment of dopamine-linked disorders such as Parkinson's disease, Huntington's disease, and schizophrenia.