The physiological process by which a given neuron uses one or more neurotransmitters to regulate diverse populations of neurons. The endocannabinoid system (ECS) is a regulatory system; it regulates other systems in the body, including the brain, the motherboard of the central nervous system. When the ECS is deficient, it has problems regulating the other systems. As opposed to other cannabinoids, CBD is a neuro-modulator.