Science – Some animals don’t need a brain to learn things – Publimetro México

Madrid, 4 (Europe Press)

We automatically associate the learning and memorization faculties with the existence of the brain. In fact, science already knows a lot about the different functions found in different regions of the brain of humans, mice, and insects. However, not all animals have a brain. Cnidarians such as anemones, jellyfish, and corals have rudimentary nervous systems.

“We often assume, somewhat naively, that these creatures can only act at the level of reflection,” Professor Simon Sprecher of the University of Freiburg’s Department of Biology explained in a statement.

In a study recently published in the Proceedings of the National Academy of Sciences (PNAS), Dr. Sprecher and his team show that the assumption is simply not true. They have successfully demonstrated that the star anemone (Nematostella vectensis) has a simple type of memory and is able to learn through association.

The research group conducted animal tests, subjecting individuals to light and electrical stimuli either simultaneously (light flashes and electric “shocks” administered together) to create an association, or with an interval between the two so that no link was observed. This was a training anemone responded to.

Over time, those who received the two stimuli at the same time retracted their bodies as soon as the pulse of light was emitted. They learned that the flash of light was accompanied by an electric shock, classic Pavlovian conditioning. Thus, the cnidarians were able to register a link between two items in memory and adapt their behavior accordingly. “This is exactly what is called associative learning, and it is evidence that even animals that do not have a brain can show complex behavior thanks to their nervous system,” said Dr. Sprecher.

“So we have the framework to move our research forward,” he added. Now that we know that brainless creatures are capable of learning, a question arises. How did they do it? “We know very little about how the learning process works in animals that have apparently simple nervous systems. Our hypothesis is that some synapses are also enhanced.” Is there some kind of nerve center? Are there areas mainly devoted to the organization of the learning process? Or is the whole process evenly distributed throughout the body? How do neurotransmitters communicate with each other? These are some of the questions that emerged from the study, which Dr. Sprecher and his team will now discuss.

These observations raise another question. When and how did the ability to learn originate in evolution? Dr. Sprecher noted, “The earliest ancestors of all animals with a brain lived about 560 million years ago. Those with a nervous system appeared between 100 and 150 million years earlier.” Have animals been able to learn for longer than we thought until now? “This is a very interesting question that is definitely worth studying.”