CRH and neoplasm: Next, to determine the direct functional effects of activation of CeMCRH neurons on the activity of sympathetic nerves distributed in the tumor stroma, we injected Cre-dependent recombinant adeno-associated virus (rAAV) expressing channelrhodopsin-2 (ChR2, light-gated cation pumps can depolarize neurons and evoke action potentials) fused with mCherry (rAAV2/9-EF1α-DIO-ChR2-mCherry) together with rAAV2/2-CRH-Cre virus into the bilateral CeM and implanted optical fibers above the bilateral CeM for optogenetic activation of these neurons.