Stanford University neuroethologist Eva Fischer points out that although nearly all creatures-be it humans or animals-tend to their young, it is not yet clear how the brain produces whatever it is that's responsible for parental behaviors. To look into this, Fischer and her team observed the parenting strategies of three species of poison dart frogs. These are the Dendrobates tinctorius, the species where the male parents take care of their young, the Oophaga sylvatica, where the female parents take care of their young, and the Ranitomeya imitator, where a monogamous male and female couple take care of their young.
While 25 frogs were carrying their tadpoles to the water, that is, while their nurturing tasks as parents still influenced the frogs, the researchers quickly killed them to be able to look at their brains. In addition to these 25 frogs, the brains of 59 others that were non-caregiving or were the caregivers' partners were also involved in the experiment.
Looking at the brains of the caregiving parents, the preoptic area of the brain was lit up. This part of the brain was observed in the non-caregiving parents as well and it showed that it was not lit up. For all vertebrates, including mammals, the preoptic area is known to be linked to parental strategic behavior.
Aside from the preoptic area, the medial pallium was also observed with activity while the parents of all the three species were carrying their tadpoles. This medial pallium is a part of the brain of an amphibian that is analogous to the hippocampus of mammals. The researchers have theorized that this part of the brain was active during that time because the frogs may have been utilizing mental maps to move their offspring to the water.
As reported in Proceedings of the Royal Society B, these two parts of the brain in both the male and female amphibians are linked with caring for the young. But there were a few differences pointed out in determining which neurons were active between the male and the female parents and among the three species. One of these differences would be that a particular neuron previously linked to grooming, when it comes to the preoptic area of the brain of mice, was found to be linked to parental caregiving in the R. imitator species of poison dart frogs, but not in the other two.
With this research, it may be deducted that although there is a fundamental idea in the parenting strategies of vertebrates, there is still a difference in the neural wiring for parenthood for different species, and what energizes this neural network. And this is yet to be discovered by scientists.
