ABSTRACT
[Objective ] Intrastriatal Parr interneurons are considered to be the junction between striatal input and output neurons. This study purposes to confirm the morphology of Parr neurons and their distribution in striatum. [Method] Adult male SD rats were perfused and the brains were removed. The sections were conducted with a semiconductor-frozen microtome, then single labeling and double labeling were immunocytochemically conducted with PAP technique. Positive neurons were observed, counted, and calculated, and analyzed with SPSS. [Results] The distribution of Parr positive neurons in striatum was inhomogeueous, and was the most dense in the dorsal lateral area (P<0.001) ; the distribution of Parr positive neurons in matrix compartment was apparently more than patch compartment (82.0% vs 18.0%, P<0.001); Parr positive neurons in striaturn were medium-sized cell bodies with polygonal or oval in shape (mean diameter is 11.68 μm), and were larger in the lateral area than that in the medial area (P<0.01) ; the positive dendrites were dense and smooth without dendrite spines; the positive axons 1 were slender and their collaterals extended in striatum. [Conclusion] The characteristic of Parr positive neurons collecting mostly in lateral striatum and matrix eompartment, as well as their traits of intemeurons, indicated that they would affect the striatal projection neuronal function.