PURPOSE: To provide dose-response data for the safe and effective use of MnCl(2) for manganese (Mn(2+)) -enhanced MRI (MEMRI) of the visual pathway. MATERIALS AND METHODS: Retinal ganglion cell (RGC) toxicity, CNR in MEMRI, axon density resolution for MEMRI, mode of axonal transport and clearance of Mn(2+) from the vitreous after ivit were investigated. After 0, 30, 150, 300, 1500, and 3000 nmol ivit MnCl(2), neural toxicity was measured by counting surviving RGC back-filled with FluroGold (FG), CNR of the vitreous body and visual pathway by three-dimensional (3D) MEMRI, resolution of ON axon density by correlating CNR with axon density, and axonal transport of Mn(2+) by studying CNR in 3D MEMRI of the ON after ion of 200 nmol MnCl(2). RESULTS: There were no changes in RGC density after ivit MnCl(2) <or= 150 nmol, and reductions of 12%, 57%, and 94% occurred after 300, 1500, and 3000 nmol MnCl(2). CNR increased in the visual pathway with MnCl(2) <or= 300 nmol, and decreased when the dose was raised further. Minimum detectable ON axon densities were 125,000/mm(2). After 200 nmol ion MnCl(2), CNR>0 were recorded distally from the ion site, but there was no signal in the retina. At ivit doses >1500 nmol, clearance from the vitreous body was impaired. CONCLUSION: The optimal dose for MEMRI of the rat visual pathway was found to be 150-300 nmol ivit MnCl(2). Higher doses are toxic, causing RGC death, impair active clearance from the vitreous, and loss of Mn(2+) enhancement throughout the visual pathway. Mn(2+) traffic within RGC axons is mediated mainly by anterograde transport. (c) 2008 Wiley-Liss, Inc.
PURPOSE: To provide dose-response data for the safe and effective use of MnCl(2) for manganese (Mn(2+)) -enhanced MRI (MEMRI) of the visual pathway. MATERIALS AND METHODS: Retinal ganglion cell (RGC) toxicity, CNR in MEMRI, axon density resolution for MEMRI, mode of axonal transport and clearance of Mn(2+) from the vitreous after ivit were investigated. After 0, 30, 150, 300, 1500, and 3000 nmol ivit MnCl(2), neural toxicity was measured by counting surviving RGC back-filled with FluroGold (FG), CNR of the vitreous body and visual pathway by three-dimensional (3D) MEMRI, resolution of ON axon density by correlating CNR with axon density, and axonal transport of Mn(2+) by studying CNR in 3D MEMRI of the ON after ion of 200 nmol MnCl(2). RESULTS: There were no changes in RGC density after ivit MnCl(2) <or= 150 nmol, and reductions of 12%, 57%, and 94% occurred after 300, 1500, and 3000 nmol MnCl(2). CNR increased in the visual pathway with MnCl(2) <or= 300 nmol, and decreased when the dose was raised further. Minimum detectable ON axon densities were 125,000/mm(2). After 200 nmol ion MnCl(2), CNR>0 were recorded distally from the ion site, but there was no signal in the retina. At ivit doses >1500 nmol, clearance from the vitreous body was impaired. CONCLUSION: The optimal dose for MEMRI of the rat visual pathway was found to be 150-300 nmol ivit MnCl(2). Higher doses are toxic, causing RGC death, impair active clearance from the vitreous, and loss of Mn(2+) enhancement throughout the visual pathway. Mn(2+) traffic within RGC axons is mediated mainly by anterograde transport. (c) 2008 Wiley-Liss, Inc.
Authors: Karl-Heinz Herrmann; Silvio Schmidt; Alexandra Kretz; Ronny Haenold; Ines Krumbein; Martin Metzler; Christian Gaser; Otto W Witte; Jürgen R Reichenbach Journal: MAGMA Date: 2011-10-22 Impact factor: 2.310
Authors: Dipanjan Pan; Shelton D Caruthers; Angana Senpan; Ann H Schmieder; Samuel A Wickline; Gregory M Lanza Journal: Wiley Interdiscip Rev Nanomed Nanobiotechnol Date: 2010-09-21
Authors: Leon C Ho; Bo Wang; Ian P Conner; Yolandi van der Merwe; Richard A Bilonick; Seong-Gi Kim; Ed X Wu; Ian A Sigal; Gadi Wollstein; Joel S Schuman; Kevin C Chan Journal: Invest Ophthalmol Vis Sci Date: 2015-06 Impact factor: 4.799
Authors: Stefanie Fischer; Christian Engelmann; Karl-Heinz Herrmann; Jürgen R Reichenbach; Otto W Witte; Falk Weih; Alexandra Kretz; Ronny Haenold Journal: J Vis Exp Date: 2014-07-22 Impact factor: 1.355