Nav: Home

Social behavior of male mice needs estrogen receptor activation in brain region at puberty

July 19, 2016

A research team led by Dr. Sonoko Ogawa at the University of Tsukuba showed that activation of an estrogen receptor in a region of the limbic system during the pubertal period is needed for adult mice to express typical male social behaviors.

Tsukuba, Japan - Testosterone plays a major role in controlling behavior associated with masculinity in many mammals. In early development, testosterone is involved in the formation and organization of "male" neural pathways, on which it then acts to regulate various behaviors in adulthood. Testosterone binds and activates estrogen receptor alpha (ERα) after it is converted into estradiol by a process known as aromatization. ERα is known to function differently in different parts of the adult mouse brain. Inhibition of ERα in the medial preoptic area (MPOA) of the adult hypothalamus reduces sexual behavior but has no effect on aggressive behavior, while neither behavior is affected by ERα inhibition in the medial amygdala (MeA) of the adult animal. However, until now it was unclear whether ERα is involved in the organizational action of testosterone on the formation of neuronal circuitry for male social behavior during puberty. Researchers at the University of Tsukuba have shown that inhibiting ERα in the MeA before puberty in male mice reduces both sexual and aggressive behavior in adults. In contrast, the effects of ERα knockdown in the MPOA before puberty did not differ from knockdown effects in adulthood. The study was reported in Proceedings of the National Academy of Sciences of the United States of America.

Behavioral responses to sexually receptive females such as mounting, and toward intruder males such as biting and attacks, were recorded in adult mice. The reduction of both sexual and aggressive behavior by ERα silencing in the MeA before puberty but not in adults suggests the importance of the receptor in this location during puberty. "ERα knockdown in the MeA may even have affected the onset of puberty itself", first author Dr. Kazuhiro Sano says. "This contrasts with the silencing of ERα in the MPOA, which reduced sexual but not aggressive behavior in mice, regardless of the time of knockdown treatment." These findings suggest that ERα gene expression in the MPOA does not control male aggression through either the organizational role of testosterone at puberty, or its regulatory role in adulthood.

To understand why ERα silencing in different areas of the brain had varying effects, the team examined MeA cells. They found that neuronal cells were greatly reduced in MeA in which ERα expression had been inhibited before puberty. "ERα in the MeA seems to be necessary for testosterone to masculinize the neural circuitry for social behavior during puberty", corresponding author Dr. Sonoko Ogawa explains. "If this masculinization is incomplete, social signals that enable adults to express male social behavior may not function correctly."
The article, "Pubertal activation of estrogen receptor α in the medial amygdala is essential for the full expression of male social behavior in mice" was published in the Proceedings of the National Academy of Sciences of the United States of America (DOI:10.1073/pnas.1524907113).

University of Tsukuba

Related Testosterone Articles:

Testosterone makes men less likely to question their impulses
A new study shows that testosterone makes men less likely to realize when they're wrong.
Testosterone treatments may increase cardiac risks
A new JAMA study found a 20 percent increase in arterial plaque among men aged 65 and older who received testosterone replacement therapy for a year,
Benefits of testosterone therapy in older men are mixed
Older men with low testosterone levels showed improved bone density and strength, as well as reduced anemia, after one year of testosterone therapy, according to a new study conducted at Yale and other sites.
Testosterone therapy provides protection against cardiovascular disease in men with low testosterone
Despite the continued controversy surrounding the use of testosterone in men who have testosterone deficiency (hypogonadism), a new study has found that long-term use of testosterone therapy not only improves vigor and vitality, but may reduce the risk of death due to cardiovascular (CV) disease.
Enzyme that digests vitamin A also may regulate testosterone levels
Bco1, an enzyme that metabolizes beta carotene, may play a vital role in testosterone metabolism as well, according to a new study led by researchers at the University of Illinois.
'Mean girl' meerkats can make twice as much testosterone as males
Testosterone. It's often lauded as the hormone that makes males bigger, bolder, stronger.
Experts take strong stance on testosterone deficiency and treatment
In an effort to address widespread concerns related to testosterone deficiency (TD) and its treatment with testosterone therapy, a group of international experts has developed a set of resolutions and conclusions to provide clarity for physicians and patients.
Scientists develop recipe for testosterone-producing cells
Researchers led by teams at the Johns Hopkins Bloomberg School of Public Health and Wenzhou Medical University of China have discovered a way to keep adult stem cells that are destined to become testosterone-producing cells multiplying and on track to fulfill their fate, a new study reports.
Testosterone therapy decreases hospital readmissions in older men with low testosterone
A new large-scale population-based study from The University of Texas Medical Branch at Galveston showed for the first time that older men using testosterone therapy were less likely to have complications that require them to go back to the hospital within a month of being discharged than men not using this therapy.
Researchers: Testosterone treatment effective for older men
As men age, their sexual function, vitality and strength can decline, but researchers had not yet established whether testosterone treatment is actually beneficial.

Related Testosterone Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...