Across the animal kingdom, the vast majority of neurons in the adult brain have been generated and integrated into neuronal circuits during embryogenesis. The number and composition of post-mitotic neurons do not change much across post-natal lifespan, yet our behaviors vary dramatically across different developmental stages. How can this be?
Previous research has shown that post-mitotic neurons continue to change phenotypic properties (for example, electrophysiological properties) and rewire synaptic connections throughout post-natal juvenile stages until an animal has reached a fully mature state in adulthood. Components of the intricately timed maturation process occur independent of the individual’s experience and exposure to environmental stimuli, and suggest that cell-intrinsic genetic timer mechanisms coordinate the maturation of the nervous system. Simultaneously, neurons adapt to changing environmental conditions throughout their long post-mitotic lifespan to accommodate processes such as learning.
At the intersection of neuroscience, developmental biology, genomics and genetics, the central question that the Sun Lab is addressing is how post-mitotic neurons integrate cell-intrinsic genetic timer programs and cell-extrinsic environmental inputs to regulate the progression of the nervous system’s plastic molecular and functional states across post-natal lifespan.