METHODS: Fish were injected with 100 μg/g of MPTP intraperitoneally once or twice and then assessed on days 1 to 30 post-injection.
RESULTS: Between one-time and two-time injections, there was no significant difference in most locomotor parameters, expressions of tyrosine hydroxylase-2 (th2) and dopamine transporter (dat) genes, and dopaminergic neurons (tyrosine hydroxylase positive, TH+ cells) counts. However, caspase-3 levels significantly differed between one- and two-time injections on the day 1 assessment.
DISCUSSION: Over a 30-day period, the parameters showed significant differences in swimming speed, total distance traveled, tyrosine hydroxylase-1 (th1) and dat gene expressions, caspase-3 and glutathione protein levels, and TH+ cell counts. Days 3 and 5 showed the most changes compared to the control. In conclusion, a one-time injection of MPTP with delayed assessment on days 3 to 5 is a good PD model for animal studies.
RESULTS: Descriptive analysis shows that the farmers claimed to have a high level of self-efficacy, and perceived GM crops as possessing high benefits which translate into a highly positive attitude towards GM crops. However, at the same time, they rated GM crops as involving moderate risks and would incur moderate costs to farm, as well as acknowledging a low level of support from the government. The structural equation model (SEM) analysis demonstrates that five factors have been identified as direct predictors of attitude to GM crops: government support (ß = 0.364, P