Prof. Dr. Gilles Laurent

Research Priorities: Cellular and systems neuroscience, brain evolution, self-organisation of dynamic systems

Gilles Laurent is a French veterinarian and neuroethologist who researches animal behaviour and its underlying neural processes. His work centres around the dynamics of neural networks and how they influence perception, movement, sleep, and behaviour. He studies these principles in various animal species and his work combines quantitative behavioural observations, molecular and anatomical analyses, electrophysiological techniques, and modelling approaches.

Gilles Laurent sees brains as a self-organised dynamical systems that, through evolution, found a variety of solutions to shared biological problems. In order to uncover the potential underlying principles of brain computation, he has worked on model organisms such as grasshoppers, fruit flies, zebra fish, lizards, rats and cuttlefish and on diverse questions. 

For example, he showed that smells are initially represented not by individual neurons, but instead by time-dependent activity patterns in large cell groups. Information is thus found in patterns that changes through neuronal space and through time. His group described these patterns as movements on low-dimensional surfaces, known as manifolds, within high-dimensional neuronal state spaces. Manifolds can be described as geometric surfaces on which the activity of many neurons can be represented in a simplified manner. Even though the brain can assume billions of different states, the actual patterns of activity occur along these low-dimensional pathways like movements on an invisible topological terrain. 

Laurent is also interested in the structures surrounding sleep. Studies on reptiles show changing states which are similar to either deep sleep or rapid eye movement (REM) sleep, a phase of intense dreaming. Gilles Laurent discovered that these phases are controlled by paired neural networks that operate rhythmically like coupled internal metronomes. His research aims, by working on small and evolutionarily older brains, to identify concepts and principles that apply as well to the human brain.

Using a comparative and evolutionary perspective, neuroethologists look for universal principles which can be found across different brain architectures. His lab showed for example, that many structures of the mammalian brain, including the cerebral cortex and the hippocampus, have evolutionary roots in the common ancestral lineage of reptiles and mammals. A study conducted by his team used single-cell transcriptomics to provide evidence that fundamental elements of the cortex are far older than previously assumed. With these methods, the active genes of individual nerve cells are detected, thus generating a molecular profile for each neuron. Gilles Laurent’s research has transformed the view of brain evolution from one centred around mammals to a perspective based on a deeply anchored biological intelligence.

His integrative approach is also apparent in his research on cephalopods. He was able to show that cuttlefish process visual textures dynamically and contextually rather than simply reflexively. Pigment cells react to spatial frequencies in groups and in a coordinated fashion and represent neural processing within the brain.

Gilles Laurent’s work demonstrates that size is not a prerequisite for complexity. Even small, evolutionarily old brains use many of the same principles as the human brain does, including synchronisation, feedback, and rhythmic dynamics. He has fundamentally expanded our understanding of brain function and evolution. Thought, perception, and behaviour did not come about as sudden innovations. Rather, they are the result of a long, complex history of neural self-organisation.