To do so, we studied expression levels of the α-2A adrenergic receptor (Adra2a), G alpha proteins (stimulatory subunit-Gαs [Gnas] and inhibitory subunit-Gαi [Gnai1 and Gnai2]), and downstream protein kinase A (PKA) catalytic [Prkarcα and Prkarcβ] and regulatory subunits [Prkar1α, Prkar1β, Prkar2α, and Prkar2β]) in the frontal cortex (FC) of MS rats. This evidence concerns the gene PRKAR2A and myeloid sarcoma.