ABSTRACT
OBJECTIVE@#To investigate the therapeutic effect of Epothilone D on traumatic optic neuropathy (TON) in rats.@*METHODS@#Forty-two SD rats were randomized to receive intraperitoneal injection of 1.0 mg/kg Epothilone D or DMSO (control) every 3 days until day 28, and rat models of TON were established on the second day after the first administration. On days 3, 7, and 28, examination of flash visual evoked potentials (FVEP), immunofluorescence staining and Western blotting were performed to examine the visual pathway features, number of retinal ganglion cells (RGCs), GAP43 expression level in damaged axons, and changes of Tau and pTau-396/404 in the retina and optic nerve.@*RESULTS@#In Epothilone D treatment group, RGC loss rate was significantly decreased by 19.12% (P=0.032) on day 3 and by 22.67% (P=0.042) on day 28 as compared with the rats in the control group, but FVEP examination failed to show physiological improvement in the visual pathway on day 28 in terms of the relative latency of N2 wave (P=0.236) and relative amplitude attenuation of P2-N2 wave (P=0.441). The total Tau content in the retina of the treatment group was significantly increased compared with that in the control group on day 3 (P < 0.001), showing a consistent change with ptau-396/404 level. In the optic nerve axons, the total Tau level in the treatment group was significantly lower than that in the control group on day 7 (P=0.002), but the changes of the total Tau and pTau-396/404 level did not show an obvious correlation. Epothilone D induced persistent expression of GAP43 in the damaged axons, detectable even on day 28 of the experiment.@*CONCLUSION@#Epothilone D treatment can protect against TON in rats by promoting the survival of injured RGCs, enhancing Tau content in the surviving RGCs, reducing Tau accumulation in injured axons, and stimulating sustained regeneration of axons.
Subject(s)
Animals , Rats , Disease Models, Animal , Epothilones , Evoked Potentials, Visual , Nerve Regeneration/physiology , Optic Nerve Injuries/metabolism , Rats, Sprague-Dawley , Retinal Ganglion Cells/physiologyABSTRACT
AIM:To investigate the changes of visual development produced by monocular atropinization in rats. METHODS: Twenty normal SD rats were randomly divided into two groups: control group ( n = 10 ) and atropinization ( experimental) group ( n=10 ) . All the left eyes were selected as the experimental eyes, and the right eyes served as the normal eyes. The left eyes in atropinization group was produced by 1% atropine, 3 times a day and the right eyes in control group was treated with normal saline, 3 times a day. The flash visual evoked potentials ( F-VEP ) and retinoscopy refraction of the rats'both eyes were detected at five time points:0, 7, 14, 21, and 28d after atropinization, respectively. After 28d, six rats were randomly selected from both groups and each group had three rats. The expression of the c- fos mRNA was observed in both visual cortexes. Another six rats were chosen for the same test after 2d dark environment with 2h light later. The expression of c-fos mRNA was detected again. RESULTS: After 14d anisometropia was observed in experimental group, the difference was 3. 9D ( P 0.0 5 ) , F-VEP P1 wave of the rats left in experimental group was reached to 88. 9±1. 889ms at 21d, there was statistical difference compared with the right eye ( PCONCLUSION: In the critical period of visual development, monocular chronic atropine in rats can form anisometropia, may delay the transmission of the optic nerve, hinder the normal development of the visual cortex. Monocular atropinization in rats can be used as the model of anisometropia.
ABSTRACT
Background and Aim: Children with periventricular leucomalacia (PVL) are known to have visual impairment of various forms starting from reduced vision, field defects, congnitive problems, and problems with hand eye coordination. There is very scant data/literature on the visual evoked potentials (VEPs) at an early age in children with PVL. We did a study to evaluate the flash visual evoked potentials (fVEPs) in children with PVL less than 1 year of age. Materials and Methods: A total of nine children diagnosed as having PVL on magnetic resonance imaging were included in the study. The mean age was 9.7± 3.5 months. All children underwent handheld fVEPs under sedation at two different flash frequencies 1.4 and 8 Hz. Results: The mean latency of N1 and P1 on stimulation with 1.4 Hz was 47.9± 15.2 and 77.7± 26.0 ms, respectively. However, on stimulation with 8 Hz the mean latency of N1 and P1 was 189.8± 25.6 and 238.4± 33.6 ms, respectively. The mean amplitude with 1.4 Hz and 8 stimulation frequency was 5.6± 4.5 and 5.59± 3 mV, respectively. Conclusion: We have found for the first time that there is a change in the latency and the delay occurs at 8 Hz frequency but not at 1.4 Hz. We also conclude that amplitudes by fVEPs may be normal even in presence of periventricular changes. The amplitudes of fVEPs are not reliable in children with PVL.
ABSTRACT
Objective To investigate the effect of human umbilical cord blood stem cells on flash visual evoked potentials (F-VEP) of the traumatic optic neuropathy rats.Methods Forty-eight Sprague-Dawley rats were randomly divided into an injury group (Group A) and 3 treatment groups (Groups B,C,and D).A traumatic optic neuropathy model was built in Group A,and the rats in Groups B,C,and D were injected with the neurotrophic factor,human umbilical cord blood stem cells,and the mixture of the neurotrophic factor and human umbilical cord blood stem cells,respectively.F-VEP was recorded in both eyes of rats at the 1st h,1st week,2nd week,3rd week,and 4th week after the optic nerve injury.Results At all time points,there were significant difference in the wave latency and amplitude between Group A and normal control eyes (P＜0.01).The differences of the wave latency and amplitude between Group A and Groups B,C,and D were statistically significant at various time points after the injury except for the wave latency at the 1st h post-operation (P＞0.05).The amplitude in Group D was higher while the latency was shorter than those of Group B at all time points since the 1st week (P＜0.05).The comparisons at the same point in the remaining treatment groups were not significantly different (P＞0.05).Conclusion The mixture of human umbilical cord blood stem cells and neurotrophic factor has a promotion effect for the recovery of F-VEP of optic nerve in traumatic optic neuropathy in rats to some degrees.