Author(s)

Yuuta Hamasaki, Tomoya Shimokawa, Kohei Ishida, Yoshimasa Komatsuzaki, Satoshi Watanabe, Minoru Saito

Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Correlative Study in Physics and Chemistry, Graduate School of Integrated Basic Sciences,Nihon University, Tokyo, Japan.
Department of Physics, College of Science and Technology, Nihon University, Tokyo, Japan.

The procerebrum (PC) of the land slug Limax is the olfactory center involved in olfactory discrimination and learning. In the PC, an oscillation of local field potential (LFP) with 0.5 - 1 Hz is observed by electrophysiological extracellular recording. Additionally, spatiotemporal neural activities in the PC have been examined using optical recordings. However, extracellular recording is preferable to measure neural activities for a long time with a high speed, while it is not abundant in spatial information. In this study, we therefore attempted to elicit spatial information from extracellular recording. For this purpose, we evaluated spatial information included in the LFP compared with the spatiotemporal neural activities measured by the fluorescent voltage imaging. As a result, aversive odors induced the coherent spatiotemporal neural activities in the PC, and the increase in coherency was observed as a change in the LFP waveform. It was also evaluated as a decrease in entropy by analyzing the LFP oscillation patterns and wavelet analysis. Thus, although the LFP provides only one series of signals, the coherency of the spatiotemporal neural activities in the PC can be evaluated by applying extracellular recording with wavelet analysis.

Land Slug; Extracellular Recording; Fluorescent Voltage Imaging; Olfactory Center; Spatiotemporal Neural Activity; Coherency; Wavelet Analysis

Hamasaki, Y. , Shimokawa, T. , Ishida, K. , Komatsuzaki, Y. , Watanabe, S. and Saito, M. (2013) Coherency Evaluation of Spatiotemporal Neural Activities in the Molluscan Olfactory Center Applying Extracellular Recording with Wavelet Analysis. Open Journal of Biophysics, 3, 291-297. doi: 10.4236/ojbiphy.2013.34035.