Punkyhermy
The Origins of Sexual Conduct
Disabling or removing an auxiliary sensory organ in the nose dramatically changes the sexual behavior of female mice, suggesting that for some animals, differences in male and female behavior originate not in the brain but in the nose.
Researchers at Harvard University found that female mice acted like males, trying to mount other mice and engaging in pelvic thrusting, when a small receptor in the nose -- the vomeronasal organ -- was intentionally impaired. When the females were impregnated and gave birth, they showed little maternal behavior and soon abandoned their young.
"These results are flabbergasting," said Catherine Dulac of Harvard, who is also an investigator with the Howard Hughes Medical Institute. "Nobody had imagined that a simple mutation like this could induce females to behave so thoroughly like males."
The vomeronasal organ is especially sensitive to pheromones -- chemicals that trigger behaviors ranging from food-seeking and sexual activity to flight from danger. When the organs were removed entirely, the females engaged in male sexual behavior even though they had testosterone levels, estrogen levels and estrus cycles indistinguishable from those found in normal females. Dulac said that her team's work suggests the same neuron circuitry that results in sexually aggressive behavior in males also exists in females but is somehow repressed by the activity of the organ.
The discovery has importance for understanding sexual behavior in many land animals but not humans -- since no primates have the organ. But the findings, reported last week in the journal Nature, suggest that human sexual behavior may also be controlled somewhere other than in the brain.
-- Marc Kaufman
The Washington Post .
wow.
Disabling or removing an auxiliary sensory organ in the nose dramatically changes the sexual behavior of female mice, suggesting that for some animals, differences in male and female behavior originate not in the brain but in the nose.
Researchers at Harvard University found that female mice acted like males, trying to mount other mice and engaging in pelvic thrusting, when a small receptor in the nose -- the vomeronasal organ -- was intentionally impaired. When the females were impregnated and gave birth, they showed little maternal behavior and soon abandoned their young.
"These results are flabbergasting," said Catherine Dulac of Harvard, who is also an investigator with the Howard Hughes Medical Institute. "Nobody had imagined that a simple mutation like this could induce females to behave so thoroughly like males."
The vomeronasal organ is especially sensitive to pheromones -- chemicals that trigger behaviors ranging from food-seeking and sexual activity to flight from danger. When the organs were removed entirely, the females engaged in male sexual behavior even though they had testosterone levels, estrogen levels and estrus cycles indistinguishable from those found in normal females. Dulac said that her team's work suggests the same neuron circuitry that results in sexually aggressive behavior in males also exists in females but is somehow repressed by the activity of the organ.
The discovery has importance for understanding sexual behavior in many land animals but not humans -- since no primates have the organ. But the findings, reported last week in the journal Nature, suggest that human sexual behavior may also be controlled somewhere other than in the brain.
-- Marc Kaufman
The Washington Post .
wow.
interesting 