Functional evolution of visual involvement in experimental autoimmune encephalomyelitis. Issue 4 (October 2020)

• Record Type: Journal Article
• Authors: Marenna, Silvia; Huang, Su-Chun; Castoldi, Valerio; d'Isa, Raffaele; Costa, Gloria Dalla; Comi, Giancarlo; Leocani, Letizia
• Is Part Of: Multiple sclerosis journal, experimental, translational and clinical. Volume 6:Issue 4(2020)
• Publication Date: 2020-10
• Subjects: Experimental autoimmune encephalomyelitis -- visual system -- visual evoked potential -- electroretinogram -- optical coherence tomography; Multiple sclerosis -- Periodicals; 616.834
• DOI: 10.1177/2055217320963474
• Languages: English
• ISSNs: 2055-2173

Abstract

Background: Experimental autoimmune encephalomyelitis (EAE) is a common animal model of multiple sclerosis (MS). C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein exhibit chronic disease course, together with optic neuritis, consisting of demyelination/axonal loss of the optic nerve. Objectives: To characterize functional and structural visual damages in two different phases of EAE: pre- and post-motor onset. Methods: Visual alterations were detected with Visual Evoked Potential (VEP), Electroretinogram (ERG) and Optical Coherence Tomography (OCT). Optic nerve histology was performed at 7 (pre-motor onset) or 37 (post-motor onset) days post-immunization (dpi). Results: At 7 dpi, optic nerve inflammation was similar in EAE eyes with and without VEP latency delay. Demyelination was detected in EAE eyes with latency delay (p < 0.0001), while axonal loss (p < 0.0001) and ERG b-wave amplitude (p = 0.004) were decreased in EAE eyes without latency delay compared to Healthy controls. At 37 dpi, functional and structural optic nerve damage were comparable between EAE groups, while a decrease of ERG amplitude and NGCC thickness were found in EAE eyes with VEP latency delay detected post-motor onset. Conclusions: Thanks to non-invasive methods, we studied the visual system in a MS model, which could be useful for developing specific therapeutic strategies to target different disease phases.