Figure 3.

Oxytocinergic neurons are a target for the central therapy of ED. These neurons, originating in the PVN and projecting to the spinal cord and extra-hypothalamic brain areas, mediate penile erection. When activated by neurotransmitters, such dopamine, excitatory amino acids, NO, oxytocin, hexarelin peptide analogues, VGF peptides or by the blockade of CB1 receptors in the PVN, they facilitate penile erection, while when inhibited, for instance by gamma-aminobutyric acid (GABA), opioid peptides and endocannabinoids, this sexual response is reduced. NOS = NO synthase. References are found in Section 3.1.2. (Section 3.1.2.2 and Section 3.1.2.3).