Nigrostriatal dopaminergic lesions lead to the elongation of primary cilia of striatal neurons in rats.

<p>(A) Generation and perfusion-fixation of hemi-parkinsonian rats. Rats that received unilateral 6-OHDA injection into the nigrostriatal dopamine pathway on day 0 and displayed asymmetric rotation in the apomorphine test on day 13 were fixed on day 14, 21 or 28. Sham-operated rats were fixed on day 28. Each group included four rats. (B) A drawing indicating the dorsolateral quarter of the striatum (shaded gray), where neuronal cilia were analyzed. (C) An immunofluorescence analysis of the dorsolateral striatum from the unilaterally nigrostriatal-lesioned rat that was fixed on day 28. Primary cilia stained with an antibody to AC3 (green) protruded individually from NeuN-positive neuronal cell bodies (red) on the contralateral (contra) and ipsilateral (ipsi) sides. Insets show higher-magnification views of the boxed areas. Arrows = primary cilia; scale bars = 10 µm. (D) Lengths of AC3-positive cilia protruding from NeuN-labeled neurons were analyzed in the dorsolateral striatum. At least 200 cilia on each side from the respective animals were measured. Histograms show the distributions of cilia lengths on both sides of the striatum from a representative unilaterally-lesioned rat on day 28. (E) The average cilia length in the dorsolateral striatum of both sides from each of four rats in the respective groups was calculated. The data are expressed as means ± SEM of four average values from unilaterally 6-OHDA-lesioned rats fixed on day 14, 21 or 28, and sham-operated (Sham ope) rats fixed on day 28. In the lesioned rats, striatal neuronal cilia were significantly longer on the ipsilateral side than on the contralateral side (*<i>P</i><0.01). Significant differences were observed between the ipsilateral sides on day 28 of the 6-OHDA-lesioned rats and of the sham-operated (Sham ope) rats, and between the ipsilateral sides on day 14 and on day 28 of the 6-OHDA-lesioned rats (^#<i>P</i><0.05).