is oxytocin the “love hormone?” the answer coming from ... · is oxytocin the “love...
Post on 09-Apr-2018
221 Views
Preview:
TRANSCRIPT
Is Oxytocin the “Love Hormone?” The answer coming from both human and animal research
Amanda P. Borrowa , Liza Moscoviceb, and Nicole M. Cameronab
Psychology Departmenta , Biology Departmentb, Binghamton University NY 13902
Introduction ♡ Oxytocin (OT) is a nonapeptide released from the periventricular nucleus and the supraoptic nucleus of the hypothalamus to other brain regions and indirectly to the periphery via the posterior pituitary
♡ OT receptors are located widely throughout the brain, and are found within reproductive organs, functioning in contractility during labor and orgasm ♡ During sexual arousal and orgasm in humans, plasma OT levels increase, and OT receptor-rich brain regions show activation. These same findings are shown in other species. ♡ Additionally, OT implicated in pairbonding in humans, prairie voles, and several non-human primate species ♡ Because of its presence during mating and pairbonding, OT has often been dubbed the “love hormone.” But is this an accurate description?
Animal Research ♡ Almost all animal research has focused on central OT activity ♡ The prairie vole, a monogamous species, shows greater densities of oxytocin receptors and releases more OT during mating than its promiscuous relative, the montane vole ♡ Blocking OT in prairie voles prevents pair bonding and partner preference following mating ♡ In cotton-top tamarins, a pair-bonding primate, urine OT levels positively correlated with affiliation and sex behavior
Conclusions ♡ Love has been hypothesized to be a highly developed extension of mate preference ♡ OT is involved in pair bonding and mate preference, and is released during sex, but has yet to be definitively linked to love ♡ Our findings demonstrate that OT release during mating is more complex than previously assumed ♡ The relationship between peripheral OT and central OT is not well understood
References 1. Borrow, A.P. & Cameron, N.M. (2012) Horm. Behav.,
266-76. 2. Fisher et al. (2006) Phil. Trans. R. Soc. B. 2173-86. 3. Lim et al. (2004). J. Comp. Neurol. 555-70. 4. Mens et al. (1983). Brain Res. 143-9. 5. Schneidermann et al. (2012).
Psychoneuroendocrinology. 6. Snowdon et al., (2010) Horm Behav. 614-8.
Our Findings ♡ Natural variations in maternal care influence sexual behavior in female offspring; mothers providing Low levels of nurturing produce more promiscuous offspring ♡ We have recently shown that OT peripheral release during mating also varies as a function of maternal care received
Human Research ♡ Most human research has focused on peripheral OT ♡ Intranasal OT improved sexual functioning in males and females in several documented case studies ♡ OT increases during arousal and peaks at orgasm ♡ A recent study found higher levels of OT in new couples than in single subjects, with lower OT levels predictive of poorer relationship quality and of separation six months later ♡ Human work on OT effects within the brain has been complicated by the fact that peripheral OT administration only results in approximately 0.002% of the hormone entering the central nervous system
♡ Preliminary fMRI work has shown activation of regions dense with OT receptors ♡ The hypothalamus, an area important for mating, is activated by romantic but not maternal love ♡ Whether OT receptors are activated, and what OT release looks like in the human brain remains to be seen
Fig. 1: Basic representation of OT release within the rodent
Fig. 2: Receiving a greater number of ejaculation increases OT in Low female offspring, but decreases OT in Highs
Fig. 3: Lordosis quotient (frequency of lordosis) positively correlated with OT in High female offspring only
Fig. 4: Receiving intromissions negatively correlated with OT in High female offspring; weak positive correlation for Lows
top related