Breastfeeding promotes oligodendrocyte precursor cells division and myelination in the demyelinated corpus callosum

Demyelination alters the conduction of neuronal signals and hampers sensory-motor functions. Experimental and clinical evidence suggest that breastfeeding exerts a promyelinating impact on the maternal brain. The mechanism underlying this neuroprotective effect is not well-understood. In the present paper, we assessed the impact of rat lactation on lysolecithin-induced demyelination injury within the corpus callosum of lactating and non-lactating postpartum rats. We show that lactation enhanced the cell density of oligodendrocyte precursor cells (OPCs), but not that of activated microglia and astrocytes, within the demyelination lesion. Lactation also increased the expression of myelin markers involved in the initial stage of myelin recovery (Myelin-associated glycoprotein and 2',3'-cyclic nucleotide 3'-phosphodiesterase) and reduced the demyelination injury. Altogether, these data suggest that lactation creates a conducive promyelinating environment through increased OPCs cell division, enhanced expression of select myelin proteins, and reduced number of non-myelinated axons.