Oxytocin

by Andrea Janda

• a.k.a. alpha-hypophamine (α–hypophamine) • nonapeptide hormone (composed of nine amino acids)• Chemical Formula C43H66N12O12S2

Oxytocin (Oxt)

• created and secreted by the hypothalamus and travels down the nerve fibers to the posterior lobe of the pituitary gland where it is released into the circulatory system

Oxy- / oxus: (Greek ὀξύς) sharp, acute, swift, -tocia / -tokia: (Greek τόκος) childbirth, that which is brought forthto mean: “quick birth”

EMOTION & PAIR BONDING • oxytocin is “crucial for maternal behavior” • facilitates bonds between parent to child • facilitates bonds between lovers• released during orgasm

Oxytocinroles & functions

MOOD & RESTORATIVE• functions as an anxiolytic (anti-anxiety) • reduces blood pressure & stress hormones• allows for relaxation, growth and healing

BIOPHYSIOLOGICAL• stimulates uterine contractions in childbirth• contracts the smooth muscle layer in breasts surrounding alveoli, allowing milk let down• redistributes heat in mother’s body to warm nursing young• help’s mother’s ability to extract nutrition in the digestive process• induces social memory & calm in the infant

“fight or flight reaction”

“calm and connectionreaction”

We need a balance between exertion and stress (fight or flight reaction) and rest and recovery (calm and connection reaction)

from The Oxytocin Factor: Tapping the Hormone of Calm, Love, and Healing by Kerstin Uvnäs Moberg (2003)

After the rush of the stress response, oxytocin is partly responsible for acting as a thermostat, dialing the body’s temperature, balancing the fluids in the body, stimulating cell division and wound healing and regulating the levels of stress hormones, namely adrenaline & cortisol.

Oxytocin and vasopressin, produced in both the hypothalamus and the gonads are responsible for producing many of the behaviors associated with love and attachment.

Interaction of the oxytocin, vasopressin and dopamine systems within the brain’s reward circuitry.

Evolutionary biology describes how ancestral men and women are driven to “prefer, choose, and pursue specific mating partners” while remaining sexually faithful long enough to conceive a child, but after birth, the chemicals of attachment dampen romantic ecstasy and replace it with a “deep sense of union with a mate” that is “intricate, interesting and emotionally rewarding”

During orgasm, oxytocin floods the brain and spinal cord, stimulates the hippocampus, engages short-term and social memory and deactivates the amygdala, rendering us calm and trusting. In effect, we remember the pleasure and trust associated with the object of our affections.

Cuddle up Be Happy

LUST

LOVEROMANCE

LOVE

Sensations Brain Structures Neurochemicals

ArousalEngorgementExcitement

Right AmygdalaAnterior CingulateVentral StriatumThalamusHypothalamus (men)

Testosterone

Focused AttentionObsession

Medial insulaAnterior cingulateCaudate nucleusPutamenVentral tegmental AreaVentral pallidum

DopamineNorepinephrineLow serotonin

CalmConnection

Ventral pallidumMedial insulaCingulate gyrusPrefrontal cortexLateral orbitofrontal cortex

OxytocinDopamine

State

better the intimate bondthe more intense the sexthe more oxytocin is releasedthe greater chance that conception will occur

• thought to cause rhythmic vaginal contractions during climax

• similar contractions eject sperm

• vaginal contractions draw sperm toward the ovary with the best egg

Oxytocin released during orgasm

Oxytocin works in tandem with estrogen by prodding the fallopian tube on the side where the dominant follicle is to contract more, propelling the sperm towards the egg that’s ready to be fertilized

child rearing

pair bonding

friendships

pet interaction

One experiment found that oxytocin inhaled through an intranasal spray allowed adults playing a ‘trust’ game “to retain their trust in a stranger who was looking after their money, even though this trust was violated on many occasions”

The subjects showed decreased activity in the amygdala and the caudate nucleus, brain areas that are specifically involved in regulating fear, decision making, and risk-taking

Leonie, W. (2008). Trust in oxytocin. Nature Reviews Neuroscience

• Austistics exhibit over-activity in the amygdala • oxytocin inhalation lowers amygdala activity

Future uses . . .

Andari (2010) summarizes that with oxytocin, “patients respond more strongly to others and exhibit more appropriate social behavior and affect, suggesting a therapeutic potential of oxytocin through its action on a core dimension of autism.”

There is no Love Potion #9, but in people with in social behavior deficits, observing and understanding how people naturally form trust will give us a better understanding of mental disorders which feature these symptoms and how to treat them more effectively.

Social phobia and autism spectrum disorders

o making people feel more relaxedo increasing eye gaze and facial recognitiono promoting social approach o social comprehension o social interaction

for further

reading . . .