A novel role of oxytocin: Oxytocin-induced well-being in humans

Abstract

We review the involvement of a small molecule, oxytocin, in various effects of physical stimulation of somatosensory organs, mindfulness meditation, emotion and fragrance on humans, and then propose a hypothesis that complex human states and behaviors, such as well-being, social bonding, and emotional behavior, are explained by oxytocin. We previously reported that oxytocin can induce pain relief and described the possibility how oxytocin in the dorsal horn and/or the dorsal root ganglion relieves joint and muscle pain. In the present article, we expand our research target from the physical analgesic effects of oxytocin to its psychologic effects to upregulate well-being and downregulate stress and anxiety. For this purpose, we propose a "hypothalamicpituitary-adrenal (HPA) axis-oxytocin model" to explain why mindfulness meditation, placebo, and fragrance can reduce stress and anxiety, resulting in contentment. This new proposed model of HPA axis-oxytocin in the brain also provides a target to address other questions regarding emotional behaviors, learning and memory, and excess food intake leading to obesity, aimed at promoting a healthy life.

Ejaculate Collection Influences the Salivary Oxytocin Concentrations in Breeding Male Pigs

“…In addition to its physiological role in the mechanisms related to ejaculation, the increase in oxytocin during ejaculate collection time could also be associated with positive emotions experienced by boars during ejaculation. Oxytocin may represent a link between the social and physical feelings and emotions and sexual behavior [ 5 , 37 ], being released through sensory stimuli, such as touch, warmth and odor [ 20 , 38 , 39 ]. In addition, oxytocin has become a central component of the mechanisms mediating the well-being and anti-stress effects of positive social interactions in humans [ 40 , 41 ] and animals [ 6 , 42 ].…”

“…In addition, oxytocin inhibits the secretion of glucocorticoids, the hormones associated with anxiety and stress [ 3 ]. Moreover, it is increasingly studied in the field of positive emotions and welfare in humans [ 4 , 5 ] and animals [ 6 ].…”

The Urinary Hormonal State of Cats Associated With Social Interaction With Humans

“…Recently, oxytocin has received much attention in the field of HAI research. Oxytocin has variable functions, for example, in stress reduction, such as in decreasing the cortisol concentration and blood pressure ( 23 ), promoting well-being ( 24 ), and increasing social behavior ( 25 ). Rault et al ( 26 ) mentioned that oxytocin is an essential indicator of psychological and social well-being in domesticated animals.…”

Pain relief associated with decreased oxyhemoglobin level in left dorsolateral prefrontal cortex

“…The effect of oxytocin for pain relief should also be considered [ 17 – 19 ]. Oxytocin is a peptide hormone comprising 9 amino acids, and is synthesized in neurons of the supraoptic nucleus and paraventricular nucleus of the hypothalamus after specific stimulation of the brain [ 20 ].…”

“…Oxytocin has antinociceptive effects [ 23 , 24 ], but the molecular and cellular mechanisms of pain relief by oxytocin have not been established. We hypothesized that oxytocin secretion is increased during pain relief [ 19 ].…”