During development, the brain must lay down an incredibly complex system of connections between nerve cells that number in the billions. Central issues for this development include how nerve cells are directed to form proper connections, and to what extent nerve cell activity is necessary for connections to form normally. The visual system of mammals has been extensively studied to approach these issues, and the basic wiring patterns are well known. This project uses an important area, called the lateral geniculate nucleus, where the fibers of the optic nerve in the eye terminate on cells that project to the visual cortex. Electrophysiological recordings, optical recordings using special dyes, and pharmacological manipulations will be used to explore how cellular activity, and in particular activity correlated among particular cells, is important during prenatal development before full vision is established. Results will be important for understanding how functioning of nerve cells is important to establishing connections, and forming a bridge between a systems-level description of mammalian visual development and the formulation of cellular mechanisms to account for the process of activity-dependent development. The results may have important applicability in understanding the changes that occur in learning and memory, as well as being important for developmental biology and sensory neuroscience.
