Spontaneity in the brain

Scientists aim to understand how random behavior arises

Behavior, in general, follows a purpose. Nevertheless, it can sometimes appear spontaneous and random. For example, an animal whose escape follows a predictable pattern would be caught. The decision of a rabbit to turn left or right as the fox chases it from behind should thus have a random component. Ruben Portugues from the Max Planck Institute of Neurobiology and his collaborator, Michael Orger from the Champalimaud Foundation, wants to understand how the brain combines a stable behavioral program (such as flight) with stochastic features. The VW Foundation supports this project with a Life? research grant.

“Stochastic components of behavior are extremely important, but hard to describe”, explains the neurobiologist Portugues. “Thus, we first need to clearly define the behavior in our model organism, the zebrafish, before we establish a suited testing environment.” In this environment, the researchers plan to study behavior both in reaction to external stimulus and in “bored” fish without such external triggers.

After characterizing this behavior with random components, they will set out to discover its foundations in the brain. Using high-speed cameras and the latest microscopy techniques, they will simultaneously record the behavior and neuronal activity of zebrafish larvae. The possibility to do so is rather new. Thanks to advances in optical methods, it is now possible to visualize and manipulate the nerve cell activity in these small, transparent fish while they are moving and behaving freely. With the aid of a special tracking microscope and optogenetic methods, the scientists will aim to study the role of nerve cells individuals and as part of the network: to see if randomness can arise as an emergent property of this neuronal network activity.

To conduct this study, Ruben Portugues and his collaborator, Michael Orger from the Champalimaud Foundation , have been awarded a research grant from the VW Foundation. The program “Life? – A fresh scientific approach to the basic principles of life” will support the project with 1.3 million Euro over the next five years.

Ruben Portugues studied mathematics at the University of Cambridge, where he gained his PhD in theoretical physics in 2004. As a postdoc, he worked at the Centro de Estudios Cientificos (CECS) in Chile and the Harvard University. Since 2014, Ruben Portugues heads the Max Planck Research Group “Sensorimotor Control” at the MPI of Neurobiology. Together with his team, he investigates how sensory information and experience shapes behavior