Neuroethology: what is it and what does it investigate?

This scientific discipline combines concepts and knowledge from neurobiology and ethology.

Neuroethology is a science that studies animal behavior from the point of view of the nervous system. To do so, it uses two scientific disciplines: neurobiology, which studies the organization and structure of nerve cells and their relationship with behavior; and ethology, the branch of science that studies the behavior of animals in their natural habitat.

In this article we explain what neuroethology is, what its origins are, as well as its most relevant scientists and the main contributions to this discipline. and the main contributions to this discipline.

What is neuroethology and what does it study?

Neuroethology is a scientific discipline that studies, from an evolutionary and comparative approach, the neurophysiological mechanisms involved in animal behavior.. This relatively new neuroscience focuses on applying strategies to unravel which structures and functions of the nervous system are involved in the display of behaviors typical of different animal species.

As its name suggests, this discipline brings together the knowledge of neurobiology, which studies the functioning and organization of the cells of the nervous system that mediate behavior; and ethology, the branch of science that investigates how and why animals behave the way they do..

The German neuroscientist Jörg-Peter Ewert, one of the pioneers in neuroethological research, considers that this science aims to try to answer relevant questions, such as what physiological mechanisms explain behavior; how such behavior develops in the animal; how a certain behavior favors the adaptation of a specimen and its offspring, or what is the phylogenetic history of a certain behavior.

Specialists in neuroethology use in their scientific studies animals with unique abilities that can serve as a comparative model when studying the properties of when studying the properties of their nervous system and how it has been able to adapt throughout ontogenetic development (and at the phylogenetic level, throughout their species) to be able to display certain behaviors that fit specific contexts.

Background: ethology and Tinbergen's 4 questions

As mentioned above, neuroethology is nourished by ethology, which studies animal behavior. One of the greatest contributions to this discipline was made during the first half of the last century by the Dutch zoologist Nikolaas Tinbergen, considered one of its greatest exponents.

Tinbergen understood the behavior of animals as stereotyped motor patterns that are controlled both by internal physiological mechanisms and by certain external stimuli. According to him, each animal would be endowed with a strictly limited and highly complex behavioral machinery, which is constant throughout a species or population.

The key for Tinbergen, and for ethologists in general, was to answer the question of why animals behave as they do and, in turn, to try to understand the following clues related to that question:

What is the control mechanism underlying animal behavior?

The answer to this question would involve internal (hormonal or neural) and external factors (e.g., tactile or visual stimuli). (tactile or visual stimuli, e.g.).

How is such behavior achieved in the ontogenetic development of the animal specimen?

This answer would involve looking into the animal's history, determining the possible genetic and environmental influences that have favored such development..

What is the adaptive or survival value of a given behavior?

This answer would have to take into consideration aspects such as the evolutionary significance or selective advantage of certain animal behaviors.

How has such behavior evolved in the course of the history of the animal species?

In this case, the answer would involve accounting for the evolutionary history of the behavior in question.The aim is to analyze the evolutionary factors necessary for the emergence of behavior in the species.

Contributions of neurobiology

Neurobiology, which studies the Biological mechanisms by which the nervous system regulates behavior, is another of the scientific disciplines of neuroscience.is another of the scientific disciplines from which neuroethology draws. This science owes its origin mainly to a series of technical and theoretical advances in research on the nervous system, which also took place in the middle of the 20th century.

Several milestones marked the rise of neurobiology: the appearance of Ramón y Cajal's doctrine of the neuron, the presentation of Hodgkin and Huxley's action potential model, as well as the development of histological techniques, stimulation, recording and tracing of neural connections.

These advances facilitated Tinbergen's call in the 1970s for a synthesis of ethology and neurobiology to give way to neuroethology. to give way to neuroethology, although this was not easy at first, since there were great difficulties in obtaining adequate methods to relate the activities of individual neurons or neural tissues to the behavior of the animal in its natural habitat.

Eventually, several scientists were the driving force behind the development of neuroethology.For example, Erich von Holst, with his technique of focal brain stimulation, succeeded in demonstrating through several animal experiments that stimulation of certain areas of the brain of chickens could provoke aggressive behavior patterns; or Karl Von Frisch, Hansjochem Autrum and Ted Bullock, who pioneered research on the neurophysiological aspects underlying the specific behavior of bees, arthropods and fish.

The research of Jorg-Peter-Ewert

As mentioned at the beginning, Jorg-Peter-Ewert is one of the scientists who has done the most research in the field of neuroethology. One of his most relevant studies was carried out with amphibians, specifically with specimens of the common toad, with the aim of neural mechanisms involved in the selective responsiveness of these animals..

The German scientist studied two types of visually controlled behaviors: prey orientation or capture and avoidance or escape. To elicit capture responses, he used visual stimuli such as long, thin, dark bars (simulating worms), which provoked a rapid reaction in the toad as it moved across its retinas.

As soon as two sidebars were added to the stimulus (in the shape of an "L"), the toad's attack response tended to be inhibited (the "worm" became a "non-worm"). The animal's retinal ganglion cells responded to objects with the appropriate speed and shape, but were unable to discriminate between objects with the appropriate speed and shape.but were unable to discriminate between worm and non-worm stimuli.

The study found that stimulating a structure called the optic tectum generated the behavioral pattern associated with the toad's attack response; and on the other hand, electrical stimulation of certain parts of the thalamus elicited defensive escape and flight responses.

This research is just one example of what was once a pioneering study that contributed great knowledge to neuroethology. At present, animal behavior and its neural correlates continue to be investigated in numerous animal species: from aggression behavior in birds, predatory behavior in lizards or social behavior in primates.

Bibliographical references:

• Ewert, J. P. (1987). Neuroethology of releasing mechanisms: prey-catching in toads. Behavioral and Brain Sciences, 10(3), 337-368.
• Pflüger, H. J., & Menzel, R. (1999). Neuroethology, its roots and future. Journal of Comparative Physiology A, 185(4), 389-392.