Vertebrate brains have evolved through modifications of ancestral forms. Understanding these evolutionary changes provides key insights into brain structure and function. Our project aims to uncover how variations in embryonic development drive the emergence of novel brain structures in amniotes (mammals, birds, and reptiles), focusing on the thalamus—a critical region for information processing. While reptiles exhibit a simpler thalamic structure with multifunctional nuclei, mammals and birds show greater specialization, suggesting that evolutionary changes in neurodevelopment led to increased complexity.

Our research employs a multilevel comparative approach to study thalamic evolution. At the neurogenic level, we will map the formation timing of thalamic nuclei. At the molecular level, we will analyze transcriptional profiles of differentiating neurons. At the functional level, we will investigate thalamic connectivity, particularly with the telencephalon and midbrain. Using experimental embryology, we will conduct cell-dating experiments, neuronal tracing, and single-cell RNA sequencing (scRNAseq) in chick and gecko embryos, comparing findings with existing mouse data. By integrating developmental, transcriptomic, and connectivity data, we will identify the genetic and structural modifications that shaped the evolution of the thalamus.