Yoshihara Lab

The synapse is a specialized site of cell-to-cell contact, and is where information transfer between neurons takes place. The wiring patterns created by different types of neurons at specific synapses creates the functional logic that is the basis for information coding and processing in the brain. So, a detailed knowledge of the principles of neuronal networks is critical to understanding a wide variety of brain functions. In our laboratory, we have developed a powerful strategy for selectively visualizing neural pathways across synapses, one that combines traditional anatomical tracing and modern transgenic technology. We introduce cDNA from a plant lectin, wheat germ agglutinin (WGA), as a transgene into mice, but under the control of cell-type specific promoter elements in order to restrict its expression to particular types of neurons. With this WGA transgene technology, we are able to visualize functional neural circuits such as the olfactory, visual and cerebellar efferent pathways in these transgenic mice. With particular emphasis on the neuronal connections in the olfactory system, we are studying the cellular and molecular mechanisms that underlie the formation, maintenance, and remodeling of functional networks, and we are also seeking new concepts in neuronal connectivity patterns. In addition, we are also studying the structure, expression, and function of cell recognition and adhesion molecules at synapses in both the developing and the mature brain.