Fig. 4
From: Bruton’s tyrosine kinase-bearing B cells and microglia in neuromyelitis optica spectrum disorder
Electron microscopy analysis of axonal pathology in experimental NMO lesions. A–C Representative electron microscopy images of experimental NMO lesion in the brain of Control mice, NMO mice model either untreated, or after 5 days of BTK inhibitor treatment. D, G Edema around vessels (red asterisk) can be seen in the images of untreated NMO model but not BTK inhibitor treated group. E, H Multifocally, a breakdown of myelin characterized by separation and/or vesiculation of myelin lamellae (arrows), myelin sheath edema (green asterisk), and an extracellular edema (red asterisk) is more significant in untreated NMO model compared with BTK inhibitor treated group. F, I High-resolution transmission EM image of untreated NMO model shows naked axons (arrowheads) and microtubule disorganization. Well-arranged, densely packed microtubules are visible in NMO model with BTKi treatment. The NMO–IgG + BTKi represented NMO–IgG recipient mice with the treatment of 20 mg/kg zanubrutinib