Fig. 5.

Schematic drawing illustrating the putative interactions between OEA and the central histaminergic system. Histamine neurons are localized exclusively in the TMN of the posterior hypothalamus. Putative driver and modulatory inputs to the TMN are designated according to (24). The broken line designates presumed noradrenergic excitatory input from the NST to the TMN. According to our hypothesis, OEA induces anorexia indirectly stimulating histamine neurons in the TMN that project to the PVN. Activation of H₁ and H₂ receptors on feeding-related neurons in the PVN stimulates oxytocin release. Histamine mediates suppression of food intake also independently of OEA activating neurons in the VMH (47).