Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
J Magn Reson Imaging. 2011 Sep;34(3):670-5. doi: 10.1002/jmri.22631. Epub 2011 Jul 18.
To assess optic nerve (ON) regeneration after injury by applying manganese-enhanced MRI (MEMRI) in a study of comparative physiology between nonregenerating rat and mouse species and regenerating frog and fish species.
The normal visual projections of rats, mice, frogs, and fish was visualized by intravitreal MnCl(2) injection followed by MRI. Rats and mice with ON crush (ONC) were divided into nonregenerating (ONC only), and regenerating animals with peripheral nerve graft (ONC+PNG; rats) or lens injury (ONC+LI; mice) and monitored by MEMRI at 1 and 20 days post-lesion (dpl). Frog and fish with ON transection (ONT) were monitored by MEMRI up to 6 months postlesion (mpl).
Signal intensity profiles of the Mn(2+)-enhanced ON were consistent with ON regeneration in the ONC+PNG and ONC+LI rat and mice groups, respectively, compared with the nonregenerating ONC groups. Furthermore, signal intensity profiles of the Mn(2+)-enhanced ON obtained between 1 mpl and 6 mpl in the fish and frog groups, respectively, were consistent with spontaneous, complete ON regeneration.
Taken together, these results demonstrate that MEMRI is a viable method for serial, in vivo monitoring of normal, induced, and spontaneously regenerating optic nerve axons in different species.
通过在非再生大鼠和小鼠种与再生青蛙和鱼类物种的比较生理学研究中应用锰增强 MRI（MEMRI）来评估视神经（ON）损伤后的再生情况。
通过玻璃体内注射 MnCl2 使大鼠、小鼠、青蛙和鱼类的正常视觉投射可视化，然后进行 MRI。将视神经挤压（ONC）的大鼠和小鼠分为非再生（仅 ONC）和再生动物，用外周神经移植物（ONC+PNG；大鼠）或晶状体损伤（ONC+LI；小鼠）进行再生，并在损伤后 1 和 20 天（dpl）通过 MEMRI 进行监测。视神经横断（ONT）的青蛙和鱼类通过 MEMRI 监测至损伤后 6 个月（mpl）。
与非再生 ONC 组相比，在 ONC+PNG 和 ONC+LI 大鼠和小鼠组中，Mn（2+）增强的 ON 信号强度曲线与视神经再生分别一致。此外，在鱼类和青蛙组中，分别在 1 mpl 和 6 mpl 之间获得的 Mn（2+）增强的 ON 信号强度曲线与自发的、完全的视神经再生一致。
总之，这些结果表明 MEMRI 是一种可行的方法，可用于在不同物种中对正常、诱导和自发再生的视神经轴突进行连续、体内监测。
