S34
Origin and evolution of the nervous system
Organizers:
Osamu Koizumi (Fukuoka Women's Univ., Japan)
Kiyokazu Agata (Kyoto Univ., Japan)
Nervous system of animals is full of diversity. Insects have micro brains; cephalopods such as squid and octopus have vertebrate-like large brain. These nervous system of Protostome has main components in the ventral side (ventral cord), and called as gastroneuralia. In contrast, the nervous system of vertebrates has the main components in the dorsal side (dorsal code), and called as notoneuralia. Cnidarians have the diffuse nerve net. Echinoderm has a characteristic radial nervous system.
Considering the history of the nervous system after first nervous system appeared in the earth, three epoch-making milestones are expected. The first is the advent of nerve cells, and the second is the advent of the brain, the third is the emergence of the neural tube. Emergence of the neural tube in amphioxus (cephalochordate) led to the prosperity of vertebrates.
In this session of the symposia, we will discuss the origin and evolution of the various nervous systems. Philosophy and many experimental techniques of comparative neurobiology, molecular phylogeny, and evolutional developmental biology make it possible.
Speakers:
1) Osamu Koizumi (Fukuoka Women's University, Japan)
Origin and evolution of the nervous system viewed from the diffuse nervous system: Nerve ring of cnidarians
2) Kiyokazu Agata (Kyoto University, Japan)
How did the central nervous system evolve?
3) Shuichi Shigeno (Japan Agency for Marine-Earth Science and Technology, Japan)
Design principles of convergent brain evolution: A case of the most specialized marine invertebrates
4) Yasunori Murakami (Ehime University, Japan)
Origin and evolution of vertebrate brain
5) Takehiro Kusakabe (Konan University, Japan)
The tunicate nervous system: insights into the origin of vertebrate-specific traits