Biomedical Engineering Reference
In-Depth Information
Chapter 6
Optical Imaging Techniques for Investigating
the Function of Earthworm Nervous System
Kotaro Oka and Hiroto Ogawa
Abstract
The earthworm is a suitable animal for investigating the relationships
between its behavior and the function of its nervous system. However, this animal has
not been widely used for neuroethological research because it is not a model organism.
In this chapter, we describe the use of the earthworm as a plausible model for investi-
gating locomotion activity and learning and memory abilities using several optical
imaging techniques based on our previous studies. First, we demonstrate the useful-
ness of this animal briefl y, show its simple nervous system, and then focus on its loco-
motion mechanism in detail. Especially, we focus on experimental techniques using
several fl uorescent dyes, e.g., FM1-43 for functional imaging of specifi c synapses and
DAF for nitric oxide release from the ventral nervous system following different forms
of stimulation. Finally, we conclude this chapter with a discussion on future studies of
this animal with respect to learning and memory and imaging techniques.
Keywords
Activity-dependent labeling • Ca imaging • Earthworm • FM dyes •
Lipophilic fl uorescent dye • Nitric Oxide (NO)
6.1
Introduction
One of the fi rst and most famous experimenters using the earthworm was Charles
Darwin. He investigated the earthworm for approximately 40 years after he pub-
lished a book on soil in 1837. He published his famous book
The Formation of
