Sulfolipid-storing macrophages in the corpus callosum. Toluidine blue staining of semithin sections of the corpus callosum is shown. A, No sulfolipid-storing macrophages were found in tg/ASA(+/−) mice (line tg2645). B, In ASA(−/−) mice, some sulfolipid-storing macrophages are seen (arrow). C, In tg/ASA(−/−) mice (line tg2645), such macrophages (arrow) are larger and more numerous than in non-tg ASA(−/−) mice.