Forelimb akinesia and metabolic alteration in the striatum following unilateral 6-hydroxydopamine lesion in rats: An in vivo proton magnetic resonance spectroscopy study

The 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal dopamine system in rat can develop neuropathological and neurochemcial changes similar to those seen in patients with Parkinson’s disease (PD). The purpose of this study was to test the hypothesis that the N-acetylaspartate level (NAA), regarded as neuronal marker would be decreased after 6-OHDA lesions in rat brain and to determine whether metabolic alteration are correlated with behavioral deficit. The animals were undergone adjusting stepping test and proton magnetic resonance spectroscopy (1H-MRS). In vivo 1H-NMR spectra (TR/TE = 2500/144 ms) were acquired from both left (contralateral region) and right striatum (ipsillateral region). There was a highly significant impairment in left forepaw performance and significant reductions in NAA/total creatine (tCr) ratios were observed in the ipsillateral striatum of rat (P < 0.05). Furthermore, there was a significant correlation between left forepaw performance and NAA/tCr level on the whole sample (Spearman correlation test, ρ = 0.634, P = 0.011). Our results suggest that the NAA/tCr ratio may be a valuable criterion for evaluation of functional impairment of the striatum in 6-OHDA rat model of PD.