KU Leuven researchers on mapping octopus brains
For the first time, researchers are mapping the different cell types that occur in octopus brains. Given the amazing brainpower of these animals, it is not surprising that their brain cells display similar properties to the known neurons and glia in other animals. What is surprising is the large number of different types of brain cells. This diversity may explain why octopuses – even though they are evolutionarily some 600 million years distant from us – are still able to solve complex mental exercises. The research results were published in Nature Communications .
Octopuses have something extraordinary with their eight arms. Especially since they are able to perform complex tasks such as handling utensils, problem-solving thinking and lightning-fast camouflage that makes them blend in with the environment. This sets them apart from other invertebrates and makes them particularly intriguing. Although octopuses are evolutionarily distant from us about 600 million years, studying their brains can teach us a great deal about our own brain development, as well as about how animals think and perceive the world.
Brain Atlas
Although the shape and structure of the octopus brain is already known, we do not yet know what types of cells it contains and how they contribute to the animals’ amazing thinking and learning abilities. The research team of Professor Eve Seuntjens of KU Leuven is now changing that. They examined which cell types are present in the brains of octopuses and literally made a map of it that shows which types of brain cells there are and where they occur. The team did this by means of single-cell RNA sequencing , in which they look separately at which genes are formed in each cell of the brain. They then compared this with the genes that are active in the brain cells of fruit flies and mice.
It is no great surprise that octopus brain cells display characteristics of typical neurons and glia as we know them in fruit flies and mice. Doctoral researcher Ruth Styfhals explains: “What is surprising is the large number of different types of brain cells. What makes our cerebral cortex large is not so much the number of different cell types, but the large number of cells per type. In octopuses it is the other way around: their voluminous brain has a greater diversity of relatively rare cells.”
The world through octopus glasses
“Similarities have already been shown by our research group between the migration of human brain cells and that of octopuses at an early stage of development , but this study points to a different organization and complexity once the brain develops further, says Professor Seuntjens. “We suspect that the diversity of brain cell types in octopuses is partly at the basis of their enormous thinking capacity. In the future, further research could teach us which brain circuits are formed, what function they perform and, consequently, how octopuses perceive the world.”