Pair Bonding

Ever wonder what attracts you to your significant other and gives you a special bond with them?  A study done on monogamous voles may have surprising ties with humans.  The study (http://www.nature.com/neuro/journal/v7/n10/pdf/nn1327.pdf) has found that two chemicals found in voles (and in humans) Oxytocin (OT) and Arginine Vasopressin (AV), have found to be very important in pair bonding.  The chemical Oxytocin has been shown to be very important in both males and females however more so to females then males.  Males on the other hand, seem to be more effected by Arginine Vasopressin which leads them to be more aggressive, mark their territory and courtship.  This is interesting because both sexes show the same number of receptors for both Oxytocin and Arginine Vasopressin.  The study has been able to conclude that when Oxytocin is present in both sexes, pair bonding is increased even without mating.  If Oxytocin is blocked for any reason pair bonding is prevented and the animals do not show signs of courtship.  In addition, prenatal exposure of Oxytocin from mother to child is directly correlated with the probability that offspring will exhibit strong pair bonding later in adulthood.  Could this be true in humans as well?  Does a mother who is happily bonded to a father while pregnant give her child a greater chance of being happily bonded to an individual later in life?  Lactating females have been found to release large amounts of OT during nipple stimulation (breast feeding) which is part of the reason they are so close to their offspring.  The article finds that dopamine levels in the prefrontal cortex, nucleus accumbas and ventral palladium have been found to play an important role in pair bonding.  Is there a direct correlation between dopamine and pair bonding?  Evidence suggests that mating and pair bonding are directly correlated due to releases of Oxytocin, Arginine Vasopressin and dopamine.  In addition the specific smell of the partner stimulates the olfactory nerves which in turn, end up releasing dopamine which is why voles prefer to spend time where their partners smell is strongest.  This specific smell has also been shown to eventually release both chemicals associated with pair bonding furthering pair bonding between individuals.  The study has also found that sex releases OT and AV in both males and females with a higher level of AV being released in males and additionally a higher level of OT being released in females.  Although this specific of a study has not been conclusively done on humans, it is hypothesized that humans do in fact have similar correlations with pair bonding.