NRP1 and Peripheral demyelination: To determine whether Nrp1 expression could be upregulated in pathological conditions that are known to increase OPC proliferation, we used an acute chemically induced demyelination model created by injecting α-lysophosphatidylcholine (LPC, lysolecithin) into the corpus callosum of 2- to 3-month-old mg-Nrp1-cont and mg-Nrp1-cko mice (Fig. 4A).