Zack Johnson

A new study of prairie voles, one of the few other mammals that choose just one mate, seems to indicate that the brain's reward system is hard-wired to respond to these bonds.

Scientists have long known that socially monogamous mammals, including humans, actually change their perception of their partners when they bond as adults. What they didn't know was how the brain's neural circuitry is activated by these social interactions. This is the first comprehensive look at that question and it turns out a neural pathway that responds to rewards can be activated to increase a partner's preference for partners over strangers.

How they did it: A certain part of the brain (the corticostriatal circuit) controls the ability of animals to change their behavior in order to receive rewards. In the study, researchers used a pulsating light technique called optogenetics to systematically activate brain cells in this region in female voles that were alone. After their brain cells were bathed with light in this manner in the presence of male voles, the female prairie voles routinely chose those particular male voles over strangers.

Fun fact: The researchers also found that when the circuit's neurons were more strongly connected in females, they bonded faster with male voles they knew from earlier social settings.

What's next: The researchers say they need to test whether the circuit is necessary or just sufficient for bonding behavior and what more is involved.

Go deeper

2 hours ago - World

U.S. policy shift will allow taxpayer funding for projects in West Bank settlements

Friedman (L) with Netanyahu. Photo: Menahem Kahana/AFP via Getty Images

The U.S. and Israel will announce tomorrow that they are expanding three agreements on scientific cooperation to include Israeli settlements in the West Bank, Israeli and U.S. officials tell me.

Why it matters: This is a substantial policy shift for the U.S., which did not previously allow its taxpayers' money to be spent in the Israeli settlements.

Updated 2 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Politics: Obama: Trump is "jealous of COVID's media coverage" Axios-Ipsos poll: Federal response has only gotten worse.
  2. Health: Hospitals face a crush — 13 states set single-day case records last week.
  3. Business: Winter threat spurs new surge of startup activity.
  4. Media: Pandemic causes TV providers to lose the most subscribers ever.
  5. States: Nearly two dozen Minnesota cases traced to three Trump campaign events.
  6. World: Putin mandates face masks.

McConnell: Confirming Amy Coney Barrett will help GOP retain Senate

Photo: Samuel Corum/Getty Images

Senate Majority Leader Mitch McConnell (R-Ky.) expressed no regrets about Judge Amy Coney Barrett's controversial confirmation, telling Politico in an interview that he believes the decision to place her on the Supreme Court just a week before the election will help Republicans retain the Senate.

Why it matters: With a week to go until Election Day, many Republicans are concerned that President Trump's unpopularity could cost them the Senate. McConnell has long viewed the transformation of the federal judiciary through the confirmation of young conservative judges as his defining legacy.

Get Axios AM in your inbox

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Subscription failed
Thank you for subscribing!