THE HEALING POWER OF LOVE: THE OXYTOCIN HYPOTHESIS
HOW CAN THE NEUROBIOLOGY OF PERCEIVED SAFETY
OVERCOME TRAUMA, FEAR AND STRESS?
AN ANCIENT LOVE STORY
Sue Carter, PhD Indiana University, the University of Virginia and the University of Florida, Jacksonville
PURPOSE:
SOCIALITY AND THE HEALING POWER OF LOVE.
OXYTOCIN
IS A COMPARATIVELY MODERN HORMONE WHICH ALLOWS US TO BE “HUMAN.”
OXYTOCIN (UNIQUE TO MAMMALS) ALLOWED UNIQUE ADAPTIVE STRATEGIES, BASED ON SOCIALITY AND COGNITION.
ARE IMPORTANT
CONTEXTS FOR SURVIVAL AND REPRODUCTION, TUNING THE NERVOUS SYSTEM ACROSS THE LIFE CYCLE, ESPECIALLY IN MAMMALS, WHO INVEST HEAVILY IN THEIR BABIES
• Human existence required THE EVOLUTION OF A SOCIAL SOLUTION for dealing with Stress and Trauma in a complex world. THE EVOLUTION OF…
• SOCIAL COMMUNICATION AND SELECTIVE SOCIAL ENGAGEMENT
• SOCIAL BONDS and LASTING ATTACHMENTS
• ACCESS TO MODERN AUTONOMIC FUNCTIONS AND BIOCHEMICAL SYSTEMS that integrate sociality with health and well being
• OXYTOCIN AND THE MAMMALIAN AUTONOMIC NERVOUS SYSTEM (INCLUDING VENTRAL VAGAL CIRCUITS: VVC)
Oxytocin and the Ventral Vagal Circuitry - mediating cues of “safety” – helps to explain the evolutionary biology and benefits of social support and co-regulation across the lifespan.
“I’ve got your back”
OXYTOCIN IS A CENTRAL ELEMENT IN MAMMALIAN
MOTHERHOOD
THE BASIC PRINCIPLE OF LOVE AND CONNECTION
” If you want to go quickly, go alone. If you want to go far go together”
African proverb
SLOW FAST
BASIC PRINCIPLES: TIME MATTERS
FAST
SLOWFAST
DIFFERENT MECHANISMS EXIST FOR
ACUTE SOLUTIONS VERSUS CHRONIC SOLUTIONS
BOTH SLOW AND FAST SOLUTIONS HAVE A PLACE IN LIFE
THERE IS A BIOLOGICAL BASIS FOR BOTH STRATEGIES
CONTEXT MATTERS:
SAFETY and FEAR both have survival benefits.
The mammalian nervous system especially functions best in a SECURE SOCIAL environment.
ATTACHMENTS AND COMMUNICATION are necessary for physiological and behavioral homeostasis.
SOCIOSTASIS
The Mammalian Nervous System is adapted to use “OTHERS” to regulate all aspects of biology including emotions and behavior.
The mammalian nervous system especially functions best in a SECURE SOCIAL environment.
This is especially true in humans in early life.
ATTACHMENTS AND COMMUNICATION are necessary for physiological and behavioral homeostasis.
In the ABSENCE of a SENSE OF SAFETYThe OXYTOCIN-
VASOPRESSIN PATHWAYS & AUTONOMIC
SYSTEMS BECOME DYSREGULATEDLESS PROTECTIVE
VULNERABILITY to Mental and Physical Dysfunction
SOCIAL RELATIONSHIPS
(AND ASSOCIATED PERCEPTIONS OF SAFETY) CAN COME IN MANY FORMS
FEAR AND TRAUMA –
Can create a sense of being alone being alone
HORMONES INCLUDING OXYTOCIN –
ACTING ON THE BRAIN AND AUTONOMIC
NERVOUS SYSTEM FACILITATE BIRTH, ALLOW LACTATION & BUFFER FATHERS,
MOTHERS AND CHILDREN FROM STRESS, ESPECIALLY IN EARLY LIFE .
OXYTOCIN SUPPORTS
Love and Longevity
Overview: OXYTOCIN PATHWAYS, CRITICAL TO A SENSE OF SAFETY,
UNDERLIE CENTRAL FEATURES OF SOCIAL BEHAVIOR ASSOCIATED WITH MAMMALIAN REPRODUCTION AND SURVIVAL
REPRODUCTION & SEXUALITY
SOCIAL BONDS & LOVE
OXYTOCIN
RESILIENCE & SURVIVAL
MATERNITY, PATERNITY & GENETIC SURVIVAL
WHAT IS OXYTOCIN?
Oxytocin is a NEUROPEPTIDE MOLECULE with functions throughout the BRAIN and BODY.
OXYTOCIN is central to the biology of SAFETY & LOVE.
WHAT IS OXYTOCIN?
Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2
9 amino acids configured as a ring and a tail.
The ring in oxytocin is held together by sulfur bonds. These bonds allow oxytocin to have a high degree of biological activity and facilitating positive social behaviors, stress buffering and good health. OXYTOCIN also supports SOCIAL BONDS and LOVE.
OXYTOCIN IS A STRESS COPING HORMONE
AND A BIOLOGICAL METAPHOR FOR SAFETY
Oxytocin is made primarily in the BRAIN (HYPOTHALAMUS), and released into the blood stream at the Posterior Pituitary, but is also released within the nervous system.
Oxytocin can affect social behavior, the autonomic nervous system, and the immune system, allowing the body to ADAPT, PROTECT and HEAL especially in the face of challenge, STRESS, PAIN and CHRONIC INFLAMMATION.
Post. Pituitary
PVN SON
Oxytocin was classically viewed as a “FEMALE REPRODUCTIVE HORMONE,” acting primarily on the UTERUS and MAMMARY GLAND.
OXYTOCIN HAS EFFECTS IN BOTH MALES & FEMALES THROUGHOUT THE BODY & BRAIN.
THE HYPOTHALAMIC-BRAIN STEM
AREAS THAT PRODUCE OXYTOCIN ALSO REGULATE THE VAGUS, WITH
MANY INTERACTIONS THAT ONLY NOW BEING UNDERSTOOD.
OXYTOCIN permitted the EVOLUTION of the MAMMALIAN NERVOUS SYSTEM and eventually the EVOLUTION of the HUMAN NERVOUS SYSTEM and the
COGNITIVE EXPERIENCES WE CALL SAFETY AND
“LOVE”
HUMAN BIRTH presents special problems because of our
• BIG CORTEX and SKULL,
• BIPEDAL LOCOMOTION and
• SMALL, RIGID PELVIC GIRDLE
OXYTOCIN FACITATES BIRTH by STRONG UTERINE CONTRACTIONS
BIRTH IS ONE OF LIFE’S FIRST BIG CHALLENGES FOR MAMMALIAN MOTHER AND CHILD.. HISTORICALLY
REQUIRING OXYTOCIN TO ACCOMMODATE BIG-HEADED HUMAN BABIES
OXYTOCIN MODULATES STRESS AND PAIN:
FACILITATES Uterine contractions
FACILITATES Maternal-infant engagement
IS ESSENTIAL FOR LACTATION
REDUCES Hypoxia
IS ANTI-INFLAMMATORY
Supports TELOMERES, MITOCHONDRIA, MICROBIOME and MORE
AUTONOMIC–PEPTIDE PATHWAYS EVOLVED TOGETHER TO SUPPORT MATERNAL BEHAVIOR AND OVERCOME STRESS AND TRAUMA.
Oxytocin does not act alone.
Oxytocin does NOT act alone.
OXYTOCIN has a sibling hormoneVASOPRESSIN - from which it
OXYTOCIN (OT) has a sibling hormone –Arginine VASOPRESSIN (AVP) –from which it differs by 2 (of 9) amino acids
OXYTOCIN (OT)
Cys-TyrGln-Asn-Cys-Pro--Gly-NH2
Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2
Arginine VASOPRESSIN (AVP)
Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH2
Research in voles and now many other species has implicated oxytocin in positive social interactions, including
:
Social Engagement & Pair bonding
Maternal Behavior
Sexual Behavior
Paternal Behavior
Alloparental Behavior
However, many of other social behaviors including AGGRESSION and ANXIETY are also regulated by VASOPRESSIN
OXYTOCIN AND VASOPRESSIN ARE COMPONENTS OF AN
ADAPTIVE SYSTEM. BOTH UNDERLIE CENTRAL FEATURES OF SOCIAL BEHAVIOR ASSOCIATED WITH MAMMALIAN
REPRODUCTION AND SURVIVAL
REPRODUCTION & SEXUALITY
SOCIAL BONDS & LOVE
OXYTOCIN & VASOSPRESSIN
RESILIENCE & SURVIVAL
MATERNITY, PATERNITY &
GENETIC SURVIVAL
PTSD patients (vets mostly male) had HIGH VASOPRESSIN (AVP) AND LOW OXYTOCIN (OXT). Non-patients (first responders in SWAT training) or
Healthy RUNNERS doing an Ultramarathon did not show this pattern, even under extreme acute stress.
(from Horn, Carter et al., Comp. Psychoneuroendocrinology 2024)
PTSD patients had LOW OXYTOCIN AND HIGH VASOPRESSIN.
SOCIAL SUPPORT, IN PART THROUGH THE EFFECTS OF OXYTOCIN, MAY PROTECT AND HEAL TRAUMA.
TIME AND CONTEXT MATTER….
COMPARISONS BETWEEN OXYTOCIN and VASOPRESSIN in ADAPTIVE STRATEGIES
FUNCTIONS (AMONG MANY)
Selective POSITIVE SOCIALITY
Vasopressin is also “adaptive.” permitting DEFENSE OF SELF AND OTHERS
(vigilance, hypermobilization, territoriality, sympathetic arousal, and FEAR).
BUT… CHRONIC EXPOSURE TO THREAT HORMONES,
including
VASOPRESSIN IS DAMAGING TO THE
CONTEXT of PERCEIVED -
SAFETY
SOCIAL BONDS & LOVE
SAFETY OR CALM
IMMOBILITY WITHOUT FEAR
ANTI-INFLAMMATORY
VASOPRESSIN
THREAT or ANXIETY
AVOIDANCE & ANXIETY
DEFENSIVENESS & FEAR
MOBILIZATION or IMMOBILITY WITH FEAR?
PRO-INFLAMMATORY
CONTEXT of PERCEIVED -
VASOPRESSIN
THREAT or ANXIETY
AVOIDANCE & ANXIETY
DEFENSIVENESS & FEAR
MOBILIZATION or IMMOBILITY WITH FEAR?
PRO-INFLAMMATORY
ADAPTIVE BUT
PRIMITIVE
SOLUTIONS TO THE STRESS OF LIFE
Vasopressin (AVP) and hormones of the stress axis (HPA AXIS including CRF) are primarily pro-inflammatory - fast strategies of defense.
Oxytocin works like a fire extinguisher…
Acting as an anti-inflammatory and anti-oxidant.
Physiological states, regulated by ancient hormones and the autonomic nervous system are elements in the dynamic dance between approach and avoidance – between LOVE and FEAR.
Of particular importance to understanding Oxytocin and the
HEALING POWER OF LOVE - is the fact that these hormones act on the AUTONOMIC NERVOUS SYSTEM and regulate the VAGUS NERVE
THE VAGUS (10TH CRANIAL NERVE), SHOWN HERE, LINKS THE BODY TO THE BRAIN, AND IS CRITICAL TO EXPLAINING THE HEALTH BENEFITS
OF FEELING SAFE AND THE HEALTH RISKS OF FEAR AND ANXIETY.
OXYTOCIN & VASOPRESSIN BOTH REGULATE THE ADAPTIVE FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM AS WELL AS REGULATING INFLAMMATION AND HEALING.
THE AUTONOMIC NERVOUS SYSTEM (ESPECIALLY THE VAGAL SYSTEM) FUNCTIONS TOGETHER WITH THE OXYTOCIN SYSTEM TO FORM A COORDINATED AND INTEGRATED SYSTEM LINKING ALL ASPECTS OF PHYSIOLOGY AND BEHAVIOR INCLUDING
LONGEVITY.
FUNCTIONS (among many)
MODERN (primarily MAMMALIAN)
Selective SOCIALITY/LOVE/SOCIOSTASIS
Metaphors for SAFETY (state-dependent)
Supports adaptive cognition and cortex
DISORDERS LINKED TO OXYTOCIN DEFICIENCY OR DYSFUNCTION
(or ATYPICAL/EXCESS VASOPRESSIN)
(MOST ARE ASSOCIATED WITH EXCESS INFLAMMATION)
MENTAL HEALTH PHYSICAL HEALTH LINKED BY VAGUS/AUTONOMICS and
– VASOPRESSIN AN INTEGRATED SYSTEM INFLAMMATION
OXYTOCIN IS ANTI-INFLAMMATORY
VASOPRESSIN PREDOMINANTLY PRO-INFLAMMATORY
Oxytocin receptors are in the brain, digestive system, immune system, bone and muscle. Oxytocin is needed for the optimal beneficial effects of probiotic bacteria (microbiota) and to balance inflammation.
CARDIOVASCULAR SYSTEM
BLOOD PRESSURE
Immune System
Bone Muscle
IS LOVE EPIGENETIC via EFFECTS OF OXYTOCIN? YES
Oxytocin during birth and in the postpartum period epigenetically calibrates the OXYTOCIN RECEPTOR (OXTR)
Maternal oxytocin reduces OXTR methylation
OXYTOCIN signaling AND LOVE confer NEUROPROTECTION during BIRTH - and in the POSTPARTUM PERIOD
(modified from Danoff, Connelly, Morris and Perkeybile, Comp Psychoneuroendocrinology 2021)
Both the OXYTOCIN and VASOPRESSIN (AVP) RECEPTORS ARE ADAPTIVELY CALIBRATED by early life experience. Similar effects are seen in other systems, especially those required to manage CHALLENGES across the LIFESPAN.
Epigenetic changes in AVP or AVP receptor genes modifies HPA axis function and may also increase vulnerability to various diseases and disorders. (reviewed in Ellis, Horn, Carter et al., 2021; diagram modified from Torok, et al., 2021).
ADVERSITY
& HPA)
Overview: OXYTOCIN PATHWAYS, CRITICAL TO A SENSE OF SAFETY,
UNDERLIE CENTRAL FEATURES OF SOCIAL BEHAVIOR ASSOCIATED WITH MAMMALIAN REPRODUCTION AND SURVIVAL
REPRODUCTION & SEXUALITY
SOCIAL BONDS & LOVE
OXYTOCIN
RESILIENCE & SURVIVAL
MATERNITY, PATERNITY & GENETIC SURVIVAL
SEX & LOVE
SEX AND BEING IN LOVE
INTENSE
Yoga training (for 1 month) was associated with an increase in average plasma oxytocin from baseline to follow-up in young schizophrenic subjects
N. Jayaram, S. Varambally, R. V. Behere,1 G. Venkatasubramanian, R. Arasappa, R. Christopher,2 and B. N. Gangadhar
Indian J Psychiatry. 2013 Jul; 55(Suppl 3): S409–S413.
CAN AWARENESS OF THE BIOLOGY OF LOVE
AND RELATIONSHIPS HELP US “SAVE THE WORLD” and SAVE OURSELVES, HEAL OR BODIES AND MINDS? PERHAPS?
This is the power of love
It originates in the biology of birth, and allows us to bond to and support others throughout life
“The soul is healed by being with children.”
F. Dostoyevsky
It is critical that we support and love the next generation - our children and each other –promoting health and healing.
