Cannabinoids modulate Olig2 and polysialylated neural cell adhesion molecule expression in the subventricular zone of...

The subventricular zone (SVZ) is a source of post-natal glial precursors that can migrate to the overlying white matter, where they may differentiate into oligodendrocytes. We showed that, in the post-natal SVZ ependymocytes, radial glia and astrocyte-like cells express cannabinoid receptor 1 (CB1), whereas cannabinoid receptor 2 (CB2) is found in cells expressing the polysialylated neural cell adhesion molecule. To study CB1 and CB2 function, post-natal rats were exposed to selective CB1 or CB2 agonists (arachidonyl-2-chloroethylamide and JWH-056, respectively) for 15 days. Accordingly, we found that CB1 activation increases the number of Olig2-positive cells in the dorsolateral SVZ, whereas CB2 activation increases polysialylated neural cell adhesion molecule expression in this region. As intense myelination occurs during the first weeks of post-natal development, we examined how modulating these factors affected the expression of myelin basic protein. Pharmacological administration of agonists and antagonists of CB1 and CB2 showed that the activation of both receptors is needed to augment the expression of myelin basic protein in the subcortical white matter.