for National Geographic News
Male zebra finches could be addicted to love.
When wooing females, the Australian songbirds feel pleasure akin to that of a drug-induced high, a new study says.
In many animals, natural stimuli such as food and sex activate the brain's reward systems. In humans, drugs such as cocaine and amphetamines can produce the same effect.
When such strong signals are sent to the brain, neurons—or brain cells—can change in ways that cause addictive behavior.
When a human or animal is "rewarded," neurons in a part of the brain called the ventral tegmental area, or VTA, cause a flood of dopamine into other areas of the brain.
Dopamine is a powerful chemical messenger associated with feelings of desire, satisfaction, and happiness.
Increased activity in the VTA is a hallmark of addiction.
In the new study, Neal Hessler and Ya-Chun Huang of the RIKEN Brain Science Institute in Japan tried to determine whether natural rewards—such as birdsong—could also increase VTA activity.
Hessler and Huang found that the male birds' brains became flooded with dopamine when they sang to females, but not when they sang for themselves.
The research is detailed online in the journal PLoS One.
(Related: "Smell May Play Role in Bird Courtship, Study Finds" [May 27, 2003].)
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