Study reveals potential role of 'love hormone' oxytocin in brain function

August 4, 2013

In a loud, crowded restaurant, having the ability to focus on the people and conversation at your own table is critical. Nerve cells in the brain face similar challenges in separating wanted messages from background chatter. A key element in this process appears to be oxytocin, typically known as the "love hormone" for its role in promoting social and parental bonding.

In a study appearing online August 4 in Nature, NYU Langone Medical Center researchers decipher how , acting as a neurohormone in the brain, not only reduces background noise, but more importantly, increases the strength of desired signals. These findings may be relevant to autism, which affects one in 88 children in the United States.

"Oxytocin has a remarkable effect on the passage of information through the brain," says Richard W. Tsien, DPhil, the Druckenmiller Professor of Neuroscience and director of the Neuroscience Institute at NYU Langone Medical Center. "It not only quiets background activity, but also increases the accuracy of stimulated impulse firing. Our experiments show how the activity of can be sharpened, and hint at how this re-tuning of brain circuits might go awry in conditions like autism."

Children and adults with (ASD) struggle with recognizing the emotions of others and are easily distracted by extraneous features of their environment. Previous studies have shown that children with autism have lower levels of oxytocin, and mutations in the gene predispose people to autism. Recent brain recordings from people with ASD show impairments in the transmission of even simple .

The current study built upon 30-year old results from researchers in Geneva, who showed that oxytocin acted in the hippocampus, a region of the brain involved in memory and cognition. The hormone stimulated – called inhibitory – to release a chemical called GABA. This substance dampens the activity of the adjoining excitatory nerve cells, known as pyramidal cells.

"From the previous findings, we predicted that oxytocin would dampen brain circuits in all ways, quieting both background noise and wanted signals," Dr. Tsien explains. "Instead, we found that oxytocin increased the reliability of stimulated impulses – good for brain function, but quite unexpected."

To resolve this paradox, Dr. Tsien and his Stanford graduate student Scott Owen collaborated with Gord Fishell, PhD, the Julius Raynes Professor of Neuroscience and Physiology at NYU Langone Medical Center, and NYU graduate student Sebnem Tuncdemir. They identified the particular type of inhibitory interneurons responsible for the effects of oxytocin: "fast-spiking" inhibitory interneurons.

The mystery of how oxytocin drives these fast-spiking inhibitory cells to fire, yet also increases signaling to pyramidal neurons, was solved through studies with rodent models. The researchers found that continually activating the fast-spiking inhibitory neurons – good for lowering background noise – also causes their GABA-releasing synapses to fatigue. Accordingly, when a stimulus arrives, the tired synapses release less GABA and excitation of the pyramidal neuron is not dampened as much, so that excitation drives the pyramidal neuron's firing more reliably.

"The stronger signal and muffled background noise arise from the same fundamental action of oxytocin and give two benefits for the price of one," Dr. Fishell explains. "It's too early to say how the lack of oxytocin signaling is involved in the wide diversity of autism-spectrum disorders, and the jury is still out about its possible therapeutic effects. But it is encouraging to find that a naturally occurring neurohormone can enhance brain circuits by dialing up wanted signals while quieting background noise."

Explore further: No oxytocin benefit for autism

More information: Oxytocin enhances hippocampal spike transmission by modulating fast-spiking interneurons, DOI: 10.1038/nature12330

Related Stories

No oxytocin benefit for autism

July 18, 2013
The so-called trust hormone, oxytocin, may not improve the symptoms of children with autism, a large study led by UNSW researchers has found.

Surprise finding shows oxytocin strengthens bad memories and can increase fear and anxiety

July 22, 2013
It turns out the love hormone oxytocin is two-faced. Oxytocin has long been known as the warm, fuzzy hormone that promotes feelings of love, social bonding and well-being. It's even being tested as an anti-anxiety drug. But ...

Oxytocin improves brain function in children with autism

May 21, 2012
(Medical Xpress) -- Preliminary results from an ongoing, large-scale study by Yale School of Medicine researchers shows that oxytocin — a naturally occurring substance produced in the brain and throughout the body— ...

Could nasal spray of 'love hormone' treat autism?

May 16, 2012
(HealthDay) -- Children with autism given a squirt of a nasal spray containing the hormone oxytocin showed more activity in brain regions known to be involved with processing social information, a small study found.

Is there a link between postpartum depression and the 'love hormone'?

May 10, 2013
UNC researchers are launching a 5-year study aimed at understanding the role of oxytocin in postpartum depression and bonding between mothers and babies.

Hormone affects distance men keep from unknown women they find attractive

November 13, 2012
Men in committed relationships choose to keep a greater distance between themselves and an unknown woman they find attractive when given the hormone oxytocin, according to new research in the November 14 issue of The Journal ...

Recommended for you

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

Lutein may counter cognitive aging, study finds

July 25, 2017
Spinach and kale are favorites of those looking to stay physically fit, but they also could keep consumers cognitively fit, according to a new study from University of Illinois researchers.

Brain stimulation may improve cognitive performance in people with schizophrenia

July 24, 2017
Brain stimulation could be used to treat cognitive deficits frequently associated with schizophrenia, according to a new study from King's College London.

New map may lead to drug development for complex brain disorders, researcher says

July 24, 2017
Just as parents are not the root of all their children's problems, a single gene mutation can't be blamed for complex brain disorders like autism, according to a Keck School of Medicine of USC neuroscientist.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.