In vivo analysis of glial cell phenotypes during a viral demyelinating disease in mice

Mice were anesthetized by methoxyfluorane inhalation followed by chloral hydrate (0.4 mg/g body weight, intraperitonaal). They were then fixed by a 10-min transcardiac perfusion of a solution of 4% formaldehyde (from paraformaldehyde) and 0.1% glutaraldehyde in 0.1 M sodium phosphate buffer, pH 7.4. Spinal cords were removed 1-4 h after perfusion and divided into pieces for further processing. Transverse slices ,x4).5 mm thick were cut from cervical, thoracic, and lumbar regions of each spinal cord, postflxed in buffered osmium tetroxide, and embedded in epoxy resin. Sections 1-2 #m thick were later cut from these blocks, stained with toluidine blue, and examined to confirm the presence of virus-induced demyelinating lesions in each infected animal.