Comparison of dopamine levels in the lateral geniculate nucleus in guinea pigs with flickering light?induced and form deprivation myopia / 中国实验动物学报

ABSTRACT

Objective To observe the dopamine(DA)concentrations in the lateral geniculate nucleus in guinea pigs with flickering light-induced and form deprivation myopia,and to compare and analyze the pathogenetic mechanisms in the centers of vision of these two different myopia models. Methods Twenty-four two-week-old guinea pigs were randomly assigned to three groups(n=8)flickering light-induced myopia(FLM)group, form deprivation myopia(FDM)group and control group. All the groups were fed for 8 weeks. The refraction and axial length(AL)were measured before and af-ter modeling. After eight-week modeling,the contents of dopamine in the left lateral geniculate nucleus were detected by high performance liquid chromatography with electrochemical detection(HPLC-ECD). Results Before modeling,no sig-nificant difference was found in refraction and AL among the three groups. After eight-week modeling,in contrast with the control group,significant differences were found in changes of both refraction(P<0.001)and AL(P<0.05)in the right eyes of FLM and FDM groups,indicating that the two myopic models were successfully established. The result of HPLC-ECD showed that the contents of DA in the left lateral geniculate nucleus in FLM group were significantly higher than the control group(P=0.01),while in the FDM group it was lower than the control group(P=0.021). The average contents of DA were as follows(37.04 ± 1.18)pg/μL in the control group;(24.27 ± 3.46)pg/μL in the FDM group; and (45.58 ± 1.98)pg/μL in the FLM group. Conclusions The content of DA in the lateral geniculate nucleus is increased in FLM,while decreased in FDM,indicating that the expression of DA in LGN and the mechanisms of formation of these two experimental myopia are different.