Toxicity of Mn2+ in MEMRI with Topical Loading

Tsen-Hsuan Lin¹, Sheng-Kwei Song²

Manganese enhanced MRI (MEMRI) with topical loading is a novel approach to investigate anterograde axonal transport of the visual pathway. There is no need to perform intraocular injection physically damaging the eye. Topical loading has been demonstrated to produce similar MEMRI results as with intraocular injections. However, it is still uncertain if visual function is affected after MnCl₂ loading. This study determined the minimum dosage for the success MEMRI and measured the visual function after MnCl₂ loading. Mouse vision was affected but slowly recovered with 0.75M MnCl₂ loading. Based on DTI parameters of optic nerve and T2W images of retina, the injured retina is likely the cause of the impaired visual function.