June 25, 2019
Written by: Rebecca Somach
In most of the articles you’ll see on this blog and in the most well-known experiments in neuroscience, scientists are usually trying to understand some kind of human behavior. They often use laboratory animals, such as mice, rats, or primates, to model these different human behaviors. They can study simple behaviors such as getting a reward after hearing a noise, or more complicated behaviors such as stress, drug addiction and gambling. However, many of these behaviors are things that animals would never do on their own. For instance, a monkey probably won’t find a casino in the middle of the forest and go gambling. While researchers have learned much about the neuroscience behind certain behaviors using animal models, there are also a subset of neuroscientists that want to study behavior in a very different way. Instead of studying how animals behave in a lab, they want to understand behaviors as they occur in nature. Furthermore, they want to understand how neural circuits drive these types of behaviors. This branch of neuroscience is known as ‘neuroethology.’
Most people have not heard of the word ‘neuroethology’. It is a word that is made of the words ‘neuro’ representing the study of neural circuits, and the word ‘ethology’ which is defined as “the study of animal behavior”1 . While it might seem trivial to study how animals behave, the study of animal behavior has contributed a lot to what we know and how we think about behavior in general. In fact, studying animal behavior has been so impactful that in 1973 Karl Von Frisch, Konrad Lorenz, and Nikolaas Tinbergen were awarded the Nobel Prize in Physiology or Medicine for their work in ethology, the study of animal behavior2. Their work explored the behavior patterns of insects, birds and fish, and involved carefully planning out experiments and studying behavior; however, they did not actually study the brains of these animals. That is the gap that brings us to neuroethology, which is another level in understanding behavior. Neuroethology is a young scientific field: the first descriptions of neuroethology as a separate discipline with its own rules were published in the 1980s3. Modern neuroscience techniques have merged with rigorous behavioral studies to create this unique discipline.
Biological sciences often study a very specific group of animals that are traditionally called ‘model organisms’. These animals were chosen because they are easy to house in lab spaces, because they breed quickly or because other scientists use them. Since these animals are common, laboratories can learn from one another and share techniques. The most common model organisms include rodents (mice and rats), Drosophila melanogaster (fruit flies), zebrafish and Caenorhabditis elegans (small worms).
A neuroethologist chooses animals in a different way. Often, a neuroethologist will pick an animal that is the “best” at whatever they want to study. For example, if a scientist wants to study the auditory system, they could study it in mice, but a neuroethologist might want to try studying bats instead. Since many species of bats echolocate, their auditory systems are specifically tuned to take advantage of that behavior. This way, scientists are studying hearing in an animal that is already a super listener. Another example is studying honeybees to learn about navigation. Honeybees need to fly very far distances and then return back to the same hive every single day, but have much simpler brains than we do. Despite this, they still manage to return home much better than most of us could with a GPS.
It might seem odd that a scientist would want to spend their time trying to wrangle critters when they could be using a more traditional model animal, so why study neuroethology? As with many areas of science, basic science research can illustrate ideas in simpler systems that are not clear in more complex animals. Some scientists want to study how children develop their ability to talk. However, this can be very complicated and it is hard to study the brains of children. Additionally, speech acquisition is difficult or even impossible to study in traditional lab animals such as the mouse or fruit fly. However, in zebra finches, a young finch will learn how to sing from its elders in a manner similar to human children. In this way, scientists can use this unique model animal to study a behavior that develops from childhood to adulthood and has a strong learning component, much like human language. This is an example of how neuroethology can attempt to understand the necessary parts of a behavior that is very difficult to understand in humans or traditional lab animals.
Some neuroethologists hope to use the principles found in one organism to develop ideas that can be broadly applicable to other fields of study. It might not seem obvious how studying these strange organisms can lead to scientific advancements, but some of the fundamentals of neuroscience were built because J.Z. Young decided to use giant squid axons as a model for studying neural transmission in the 1930s5. We can’t precisely predict how studying communication in electric fish will directly lead to medical benefits in neurological disease. We could be shocked to find out that the answers to our questions about how the brain controls behavior are swimming in the rivers of South America.
Cover Image by Gareth Webb via Pixabay, https://pixabay.com/photos/bee-honeybee-pollen-pollination-4279977/
- Ethology, Encyclopædia Britannica, (2013) https://www.britannica.com/science/ethology
- Nobel Prize Website. https://www.nobelprize.org/prizes/medicine/1973/summary/
- Ewert, J.P. (1980) An Introduction to the Neurophysiological Fundamentals of Behavior
- Helligenberg, Rose (1985) Neural correlates of the jamming avoidance response (JAR) in the weakly electric fish Eigenmannia. Trends in Neurosciences, 8:442-449
- Z. Young (1938) The Functioning of the Giant Nerve Fibres of the Squid. Journal of Experimental Biology 15: 170-185;