Males and females have essentially unisex brains — at least in flies — according
to a recent study in the journal Cell by Yale scientists who sought to identify
factors that are responsible for sex differences in behavior. — By Janet Rettig Emanuel
T H I S
The researchers showed that a courting “song and dance” routine
that only male flies naturally perform — in which one wing is lifted
and wiggled to make a humming “song” — can also be triggered
in female flies by artificially stimulating particular brain cells that are
present in both sexes.
“It appears there is a largely bisexual or ‘unisex brain.’ Anatomically,
the differences are subtle and a few critical switches make the difference between
male and female behavior,” says senior author Gero Miesenboeck, formerly
of Yale and now at the University of Oxford.
According to the authors, most male animals have to perform elaborate courtship
displays to try to convince the female that they are worthy mates. The study
was designed to see what neurons were responsible for behavior in the courtship
dance of flies, and how the neural circuits in males and females differed.
To do this, the scientists genetically engineered specific neurons in the fly
to respond to light. This optical trick allowed them to activate the neural
circuits that control the behavior pattern directly.
Using a flash of laser light as a “remote control” for the brain
cells, the researchers first identified which nerve cells control the courting
behavior in males. Next, they showed that the cells were present and functional
in both males and females, even though only males do the song and dance.
“Surprisingly, when the brain cells of female flies were flashed with the
laser cue we found that even the female flies that never normally behaved this
way began to sing,” says Dylan Clyne, a Yale postdoctoral associate and
primary investigator for the study.
“Our work shows that the brains not only look similar but are functionally
similar,” adds Clyne. “The females have all the equipment to sing,
but normally don’t use it because their song circuit doesn’t get
the appropriate activating signals.”
As to whether this study is relevant to humans, Clyne says, “You have to be careful about how much you can extrapolate
from studying flies. But, the basic principle should hold up — that is,
the idea that we don’t need big sex differences in the brain to explain
why it seems that men are from Mars and women from Venus.”
The authors’ next goal is finding the controls that set the flies’ brains
to the male or female mode. They hope that by studying examples of sex-specific
behaviors, they can clarify the still poorly understood relationships between
genes, which are the targets of natural selection, and behavior, which is the
product of evolution. Ultimately, this line of research could also shed light
on how genes underlie behavioral variation and perhaps even specific mental
illnesses.
The research was funded by the National Institutes of Health and a Patterson
Trust Postdoctoral Fellowship.
W E E K ' SS T O R I E S
Added sun does not lower breast cancer risk, warn expertsYale affiliates are honored with election to prestigious societies
Ten appointed members of American Academy of Arts & Sciences
Mathematician Peter Jones named to National Academy of Sciences
Ian Shapiro chosen to join American Philosophical Society
Strobel’s students rediscover sense of scientific ‘wonder’ . .
Yale to celebrate 307th graduation
Summertime at Yale
Scientist Joan Steitz wins nation’s largest prize in medicine
University names 18 future leaders as 2008 World FellowsENDOWED PROFESSORSHIPS
Mary E. Miller named Sterling Professor of the History of Art
Joseph Roach appointed Sterling Professor of Theater
Dr. Madhav Dhodapkar is the new Bunker Professor of Hematology
Dr. Richard Edelson is the first Lerner Professor of Dermatology
Architecture students helping to design Mideast Peace Park
China’s President Hu Jintao meets with participants in . . .
In Yale-led study, astronomers discover nine young galaxies . . .
Research on male mating behavior suggests brains may be unisex . . .
Paul Anastas honored as the founder of ‘green chemistry’
Town-gown partners honored with Elm-Ivy AwardsSCHOOL OF MEDICINE NEWS
Drug addicts can learn to save lives, says researcher
Study: No ‘Hollywood heart attack’ symptoms for most women
Findings suggest eating chocolate may be boon to pregnant women
Early-stage bone cells may offer possible estrogen replacement
Expert assesses lessons from 12 years of anti-smoking efforts
Computer program helps keep drug abusers abstinent, study shows
Noted gastroenterologist named chief medical officer at YMG
Yale Ob/Gyn researchers discuss their work at New Orleans meeting
Symposium on pain management aimed at medical school students
Exhibits explore artist’s Liverpool years, British watercolors
Two student-curated shows focus on the medium of photography
Library creates digital archive of ‘oldest college daily’
Two seniors will study at the University of Cambridge as Gates Scholars
Campus leaders discuss strategies for increasing staff diversity
Former Bucknell chaplain is named new pastor of University Church
Professor Miroslav Volf will co-teach class with . . .
Tony Blair
Council of Masters honors 10 juniors for their scholarship . . .
Conference focuses on ‘Women and Men in the Globalizing University’
The future of ‘Computers, Freedom and Privacy’ to be addressed . . .
Karyn Frick honored for contributions to women’s health
Campus Notes
Bulletin Home|Visiting on Campus|Calendar of Events|In the News
Bulletin Board|Classified Ads|Search Archives|Deadlines
Bulletin Staff|Public Affairs|News Releases|
E-Mail Us|Yale Home