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abdulhakeem
17-06-04, 01:37 PM
Scientists say they have found how to change promiscuous wayward males into attentive home-loving husbands.

Nature magazine reports that the breakthrough has been achieved with voles but has implications for humans.

By altering one gen in the brain hormone chemistry, scientists made a promiscuous meadow vole faithful - just like its prairie vole cousin.

After mating, male prairie voles "fall in love", choosing to stick close to their chosen one, guard her jealously and help her raise their young.

Closely related meadow voles, on the other hand, mate with several females and pay little attention to their babies.

A hormone called vasopressin encourages pair-bonding in prairie voles. Scientists noticed that meadow voles have fewer vasopressin receptors and decided to try giving them more.

The results were remarkable. The meadow voles changed their ways and suddenly fixed on one female, choosing to mate with only her - even when other females tried to tempt them.

"We think what happens is when the voles mate, vasopressin activates the reward centre, and it really makes the animals pay attention to who they are mating with," co-author Larry Young, from Emory University, Georgia, told BBC News Online.

"It makes the voles think: "when I'm with this partner I feel good". And from then on, they want to spend their time with that particular partner."

The strings of human behaviour might be pulled by similar hormones and similar pathways.

"We know that vasopressin is released when humans have sex," said Professor Young. "Sex is probably involved in maintaining the bond between humans and vasopressin may play a role in that."

http://www.ananova.com/news/story/sm_991480.html

abdulhakeem
17-06-04, 02:10 PM
Love rats turned into Mr Rights

Tim Radford
Thursday June 17, 2004
The Guardian

Love is blind, but lust is just a missing vasopressin receptor in the brain's reward centre. Biologists know this because by adjusting one gene they turned a libidinous love rat with a roving eye into a devoted stay-at-home rodent.

A team from the Yerkes national primate research centre of Emory University report in Nature today they imposed monogamy on a male meadow vole.

Male prairie voles are monogamous: they form lifelong pair bonds. But their cousins, the meadow voles, are promiscuous and mate frequently with many partners.

The first species has many vasopressin receptors in one of the brain's principal reward centres, the ventral pallidum. The second species does not.

So Miranda Lim and Larry Young of Yerkes used a harmless virus to transfer the vasopressin receptor gene from prairie voles into the ventral pallidums of meadow voles.

They found that the Casanova meadow voles then displayed a strong preference for their current partners and ignored the temptations offered by new females.

Dr Lim said: "The brain process of bonding with one's partner may be similar to becoming addicted to drugs: both activate reward circuits in the brain." Dr Young said: "It is intriguing to consider that individual differences in vasopressin receptors in humans might play a role in how differently people form relationships."

http://www.guardian.co.uk/uk_news/story/0,3604,1240743,00.html