RESUMO
Introduction: Despite the widespread use of the unilateral striatal 6-hydroxydopamine (6-OHDA) lesion model in mice in recent years, the stability of behavioral deficits in the 6-OHDA striatal mouse model over time is not yet clear, raising concerns about using this model to evaluate a compound's long-term therapeutic effects. Materials and methods: In the current study, mice were tested at regular intervals in the cylinder test and gait analysis beginning 3 days after 6-OHDA injection of 4 and 8 µg and lasting until 56 days post-lesion. Apomorphine-induced rotational test and rotarod test were also performed on Day 23 and 43 post-lesion, respectively. Immunohistochemistry for dopaminergic neurons stained by tyrosine hydroxylase (TH) was also performed. Results: Our results showed that both the 4 and 8 µg 6-OHDA lesion groups exhibited forelimb use asymmetry with a preference for the ipsilateral (injection) side on Day 3 and until Day 21 post-lesion, but did not show forelimb asymmetry on Day 28 to 56 post-lesion. The 8 µg 6-OHDA lesion group still exhibited forelimb asymmetry on Day 28 and 42 post-lesion, but not on Day 56. The gait analysis showed that the contralateral front and hind step cycles increased from Day 3 to 42 post-lesion and recovered on Day 56 post-lesion. In addition, our results displayed a dose-dependent reduction in TH+ cells and TH+ fibers, as well as dose-dependent apomorphine-induced rotations. In the rotarod test, the 8 µg 6-OHDA lesion group, but not the 4 µg group, decreased the latency to fall on the rotarod on Day 43 post-lesion. Conclusion: In summary, unilateral striatal 6-OHDA injections of 4 and 8 µg induced spontaneous motor impairment in mice, which partially recovered starting on Day 28 post-lesion. Forced motor deficits were observed in the 8 g 6-OHDA lesion group, which remained stable on Day 43 post-lesion. In addition, the rotarod test and apomorphine-induced rotational test can distinguish between lesions of different extents and are useful tools for the assessment of functional recovery in studies screening novel potential therapies.
RESUMO
This paper assessed the coastal environmental quality along the Beibu Gulf using a statistical approach, multi-biomarker pollution index (MPI). Samples of clam (Paphia undulata) and sediment were collected at nine sites from the intertidal zone of Beibu Gulf in April 2011. Nine biomarkers of response were measured both in gill and digestive gland in Paphia undulata, and twelve kinds of contaminants were measured in different sediment samples. According to the Pearson' s correlation coefficients between biomarker responses in Paphia undulata and contaminant levels in sediments, five biomarkers either in gill for oxidized glutathione (GSSG), reduced glutathione (GSH), glutathione S-transferase (GST) or in digestive gland for thiobarbituric acid reactive substances (TBARS) and glutathione peroxidase (GPx) were selected for MPI calculation. For each biomarker at each site, a response index was allocated, and the MPI value of this site was calculated as the sum of the response index of the five biomarkers. The results of the calculation (MPI values from 18 to 39) showed significant differences among sampling sites. The environmental quality of all sites ranged from class 1 (clean) to class 3 (lightly contaminated), and no site fell into class 4 (contaminated) or class 5 (heavily contaminated), indicating a good environmental quality in the intertidal zone of Beibu Gulf. However, the environmental quality at some sites (S1, S3, 54 and S7) fell into class 3 (lightly contaminated), indicating mild interference from human activities has occurred.