Our brain exhibits dramatic transitions in activity patterns. These transitions, or brain states, are observed during wakefulness but, strikingly, are even more prominent during sleep, when interaction with the environment is limited. To date, the function of these state transitions remains elusive.
The ReptiCode project is motivated by the understanding that our brains are not a product of careful design but rather of a long series of random modifications shaped by evolution. Thus, to understand fundamental properties of neuronal system, we must understand their evolutionary story. Further, evolution produces highly complex biological systems with large variations between multiple components. To understand the general principles underlying function we need a methodology to separate between details that are fundamental to those that are species specific. Comparative studies between animals provide the tools to achieve this. Finally, the diversity of species gives us a rich repertoire of manifestations for different biological phenomena. From those we can identify valuable animal models in which the biological question is more simply manifested or easier to study. The considerations above led us to focus our study on the brain of reptiles.
Our aim is to utilize the simpler and highly structured organization of brain states in the lizard Pogona Vitticeps, to expose the full repertoire of brain states in a naturally behaving animal. We will take advantage of the limited diversity of motor movements in Pogona, to expose the link between brain activity and behavior. Reptiles are located in a unique position in the evolutionary tree. This position allows us to understand the common vertebrate ancestor of all mammals, reptiles, and birds – the first vertebrates that became fully terrestrial and “solved” the challenges of life on land. We will therefore exploit this unique evolutionary position to reveal the forces that pushed the emergence of brain states during evolution. Finally, through a comparative analysis of brain state properties between different reptiles and mammals we will extract the fundamental properties and functions of brain states and the brain network that supports them.
