Oxytocin, Humans and Reptiles

February 22, 2015

When a mother sea turtle migrates thousands of miles, only to crawl up on some beautiful ancestral beach and immediately start digging a nest, she is doing so at the behest of a hormone almost identical to our human oxytocin. Like other members of her species (crocodiles, snakes, lizards, but not frogs) her reptilian version of oxytocin is called argine-vasopressin. Every stroke of her paddle-like legs triggers the mother turtles pituitary secretes more vasopressin to prepare her for the uterine contractions that will be necessary for laying her eggs. After she buries her eggs and crawls back into the sea her argine-vasopressin backs off too. This is where reptiles differ from humans. Mother turtles take off after laying their eggs, leaving their young to hatch and fend for themselves. Human mothers commence years of nurturing their young. As the infant begins suckling this stimulates the nerve endings in the nipple and areola which triggers the pituitary gland to release more oxytocin. The oxytocin then causes alveoli cells to contract and eject milk down the milk ducts. This is called the “let down” milk ejection reflex. The oxytocin also serves as the bonding hormone between mother and child but it doesn’t stop there. While doing all of that it stays busy working as an analgesic to dull the pain associated with giving birth. 

Both oxytocin and argine-vasopressin (AVP) are critical to mating and spawning behavior for every species. Though only separated chemically by one amino acid, they are both remarkably similar in their influence over male and female behavior. On the male side, the more oxytocin he secretes, the more sexual involvement he engages in which promotes a cascade of oxytocin which then binds to testosterone and dopamine receptors which leads to more male nurturing and anti-aggressive and forward-looking behavior. Oxytocin and dopamine are forward looking because dopamine is the anticipatory hormone. Life is always “on the come” with dopamine release. This is why so many gamblers smoke cigarettes. The nicotine triggers dopamine release and the dopamine puts them on the edge of their seats as the dice roll, the cards fall and the ponies run. But I digress, back to oxytocin. 

Argine-vasopressin doesn’t really influence family life in the world of reptiles but in the warm blooded world of mammals oxytocin supplementation has proven critical to all normal, happy home life behavior. In one study oxytocin supplementation actually caused male rats to stop murdering the babies in the warrens they have raided. Instead of going on a killing spree they prefer to settle down and mate with a favorite rat. In another study virgin female rats were administered a blood transfusion from a female that had just given birth and triggered powerful maternal behaviors in the virgin female rats. Oxytocin or Arginine-vasopressin it is a powerful hormone that, when used properly, can enhance the human condition.