NATIONAL INSITUTE FOR BASIC BIOLOGY

National Institute for Basic Biology

DIVISION OF BEHAVIOR AND NEUROBIOLOGY

(Adjunct)

Professor:
Fujio Murakami
Associate Professor:
Masato Nakafuku
Research Associate:
Atsushi Tamada
Postdoctoral Fellows:
Tatsuro Kumada 1
Hiroki Taniguchi 4
Yumiko Hatanaka 4
Graduate Student:
Hiroshi Ono (from Osaka University)


The vertebrate nervous system contains a large number of neurons that are connected to each other by specific axonal projections. We are interested in how the complex but precise neuronal network, which is indispensable for functioning of the nervous system, is constructed during development. The goal of our research in this division is to elucidate the cellular and molecular mechanisms underlying the neuronal network formation in vertebrates, with current focuses on the mechanisms of axon guidance and neuronal migration. Our laboratory was just started in April 1998 by two of the members and others joined thereafter. Plans of research but not results of experiments will be described below.


I. Mechanism of Axonal Guidance

During development of the nervous system, growing axons are guided through specific pathways to correct targets. Our research interest focuses on the cellular and molecular mechanisms of axon guidance in the vertebrate nervous system. We are particularly interested in how guidance mechanisms operating in different phases of axonal growth are assembled to generate the complex but precise axonal wiring patterns in the brain. To address these issues, we are first trying to understand axonal wiring patterns during development with reference to the structural organization of the brain. Using whole-mounted preparations of embryonic rat brains, we will reveal whole axonal trajectories by labeling with neuronal tracers, such as DiI, or by immunohistochemical staining with antibodies against molecular markers expressed in a subset of neurons. We will next explore the axonal guidance mechanisms generating these wiring patterns. Following questions will be addressed. 1) What structures along the pathway have key roles in axonal guidance? 2) What guidance cues exist in these structures? Are these attractive cues or repulsive cues? Are these short-range cues or long-range cues? 3) What molecules are responsible for these cues? 4) How do multiple guidance mechanisms work in concert to generate specific wiring patterns? To answer these questions, we use neuroanatomical techniques, in vitro culture techniques including dissociated cell, explant and whole-mount cultures, and biochemical and molecular biological techniques.


II. Mechanism of Neuronal Migration

A variety of neurons migrate from their birthplace to the position where they finally settle. We are also interested in the mechanisms underlying the neuronal migration in vertebrate central nervous system, in particular, how neurons are guided through specific routes to final positions. To address these issues, we are planning to develop in vitro culture systems that reconstruct migratory events occurring in vivo.


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Last Modified: 12:00, May 28, 1999