How does a mouse’s behavior change when it becomes a parent?
https://www.psychologytoday.com/us/blog/brain-waves/201804/how-parenting-is-hard-wired
The parent has to build a nest, groom or take care of offspring, retrieve them to the nest. The motivation of the animal in the interaction with young is completely modified. A parent is absolutely attracted to all the needs of their offspring. Before that, if young [animals] are screaming, [the adults] don’t care. Parents will also now engage in interaction with other adults very differently. Animals are no longer interested in mating because they have to take care of their offspring, or in fighting with other animals except as it relates to the protection of the young.
As a metaphor, you have kids at home. You’re going to stay at home and watch videos with them instead of going to the pub like you used to do when didn’t have any offspring. The entire life of being a parent is changed.
In 2014, we made the first breakthrough to crack this problem by identifying a particular population of neurons in [a part of the hypothalamus] that express this neuropeptide galanin. The identification of this population really gives us a handle on trying to see how these neurons work. In the 2014 paper (link is external), we showed that if you get rid of these galanin neurons, the animals, whether they are moms or dads, no longer parent. These galanin neurons are the control hub to regulate parenting behavior.