The long-term vision of the Tosches lab is to unravel fundamental principles governing vertebrate brain evolution, using neuron types as the units of analysis and comparison across species. Questions addressed in the lab include: (1) Evo-devo: how does variation of developmental processes fuel the evolution of neuronal diversity? (2) Cell types: how do neuron types in the same brain areas compare across species? (3) Circuits and behavior: do conserved neuron types and circuits have similar functions in distantly-related species?
In this talk, I will describe recent insights emerging from the analysis of the salamander telencephalon. Our transcriptomic comparison of neuron types sampled from salamanders and other vertebrate species clarifies the evolutionary origins of two areas involved in advanced cognition, the neocortex in mammals and the dorsal ventricular ridge in reptiles and birds. Furthermore, the analysis of salamander brain development reveals conserved principles for the assembly of a layered cerebral cortex. Finally, I will describe the tools and resources we are establishing to investigate the behavioral role of selected neural circuits in the salamander brain, and how salamanders can serve as models to understand brain plasticity in response to environmental changes.