Introduction
Oxytocin and dopamine are called happy hormones. These are associated with attachment and knowledge. Secure attachment is of basic importance for social beings. This provides well-being, physical and mental health. Having strong bonds and secure attachments promotes positive emotions and good emotion regulation.
What Is Oxytocin?
Oxytocin (OT) is a natural hormone that manages the reproductive systems of males and females. It also plays a role in managing labor, delivery, and lactation. It is produced in the hypothalamus but stored and released by the posterior pituitary gland.
Oxytocin is a chemical messenger in the brain and carries out many functions, including in the regulation of human behavior and social interactions.
Other functions include
- Sexual arousal.
- Identification or recognition.
- Building trust.
- Attachment in romance.
- Bonding between parent and child.
- Effects due to oxytocin in the brain are complex. Its role may be present in many conditions like
- Addiction.
- Anorexia.
- Anxiety.
- Autism.
- Depression.
- Post-traumatic stress disorder.
What Is Dopamine?
Dopamine (DA) is a neurotransmitter and a hormone. It plays an important role in many functions of the body, like movement, memory, motivation, and pleasurable rewards. Changes in dopamine levels are associated with many mental health and neurological diseases.
Dopamine is called a feel-good hormone. This system rewards the person when the person wants to do something that the individual likes. When a person does something pleasurable, this system releases more dopamine, and the person feels good. Hence, the person seeks more good feelings.
When the right amount of dopamine is present, the individual feels
- Improved happiness.
- Feel Motivated.
- Increase in alertness.
- Remains focused.
- When low levels of dopamine are present, the individual feels
- Tiredness.
- Not motivated.
- Feel sadness.
- Loss of memory.
- Mood fluctuates.
- Difficulty in sleeping.
- Problems related to concentration.
- Decreased sex drive.
- When high dopamine levels are present, the individual feels
- Euphoria.
- Increase in energy levels.
- Increased sex drive.
Other effects of high dopamine levels include
- Disturbance in sleeping.
- Feels more aggressive.
- Poor control of temptations.
How Are Oxytocin and Dopamine Related?
Oxytocin and dopamine, two neurotransmitters, are important in bonding and sociality.
Neurobiological and neurochemical mechanisms cause many psychiatric and behavioral disorders. Genetic factors, psychosocial environment, and disruption of neurotransmitter pathways in the central nervous system (CNS) are responsible for psychiatric disorders.
Dopamine is an important neuromodulator that has effects on CNS function. When there is a disruption in dopaminergic neurotransmission, an individual’s mood and behavior are greatly affected. Disrupting central dopaminergic pathways may cause Parkinson’s, schizophrenia, social anxiety, major depressive disorders, and compulsive behaviors.
Apart from endocrine regulation, oxytocin acts as a key substrate in the brain. Oxytocin regulates social behaviors, bonding, parental behavior, sexual behavior, anxiety, stress, and aggression. The role of oxytocin in social behaviors is due to its projections and receptor distribution.
Since the disruption of dopaminergic pathways in the brain causes many neurologic behavioral disorders. These disorders also affect social behavior in humans. This shows that there is an association between oxytocin and dopamine.
Oxytocin and dopamine are neuromodulators and have similar effects on social and other behaviors. Studies have also shown that receptor binding sites and neuronal fibers of oxytocin and dopamine are situated in the same areas of the CNS. They show close appositions to each other.
Another study has shown that hypothalamic oxytocin cells have shown dopamine receptors. This suggests that there is a direct regulation in the case of sexual behavior.
A study has shown that the brain nuclei regulate social behaviors, including sexual behavior and pair bonding. There is an overlapping of dopamine/oxytocin receptors and projections in these regions.
Common central brain regions like the medial preoptic nucleus (MPOA), supraoptic nucleus (SON), paraventricular nucleus (PVN), amygdala, nucleus accumbens (NA), and ventral tegmental area (VTA) are responsible for mediating socio-sexual behaviors. Hypothalamus and limbic system are responsible for socio-affiliative behaviors and reward pathways as a consequence of social interaction.
Sexual Behavior:
MPOA, SON, and PVN have a role in sexual behaviors like penile erection, and copulation. These nuclei are rich in oxytocin and are innervated by dopaminergic fibers from the incertohypothalamic system (situated in zona incerta), and these express dopamine D2-like receptors. This suggests that there is a direct regulation of hypothalamic oxytocin by dopamine.
In addition, there is the local dendritic release of oxytocin from magnocellular neurons. The PVN shows its effects through the release of oxytocin in other brain regions like the hippocampus, amygdala, VTA, and spinal cord to mediate sexual behavior components.
The hippocampus and amygdala are important in processing social emotions and memory. These also contain parts of the limbic system. The VTA, hippocampus, and amygdala receive oxytocin from the PVN. These contain oxytocin receptor mRNA and are responsive to the high pro-erectile effects of oxytocin.
Another study has found that oxytocin fibers originating from PVN lie in close apposition to mesolimbic dopamine cell bodies. This also suggests dopamine-oxytocin interactions in these nuclei.
Pair Bonding:
The limbic system is associated with pair bonding. Its projections into the prefrontal cortex mediate cognitive behaviors. The prefrontal cortex and NA receive dopaminergic and oxytocinergic innervation. Dopamine and oxytocin receptors are found in the prefrontal cortex and the NA.
In addition to mesocortical and mesolimbic stimulation, dopamine and oxytocin interact to modulate dopamine activity. Hence, these two sites, the prefrontal cortex and NA are responsible for social attachment behaviors like maternal and pair bonding.
Studies have shown that a disruption in dopamine and oxytocin pathways may result in behavioral disorders like sexual dysfunction, autism, addiction, anorexia/bulimia, and depression.
It is also found that central oxytocin pathways may become a therapeutic target for improving mood and behaviors among drug-addicted and socially deficient individuals.
Conclusion:
Oxytocin and dopamine are neurotransmitters in the brain that play a role in many bodily functions and help regulate behaviors. Hence it is important to know about oxytocin, dopamine, and their relationship.
