It is usually expressed at high levels in two types of neurons, the nociceptive ( pain ) neurons at dorsal root ganglion ( DRG ) and trigeminal ganglion, and sympathetic ganglion neurons, which are part of the autonomic ( involuntary ) nervous system.
12.
To wit, the Sympathetic Ganglion conveys the "'relexive arc "'from the genitals to the spinal cord ( and back again ), whereas the sensation of arousal / orgasm is received ( some time later ) by the brain.
