TITLE:
Spatiotemporal Neural Activity Changes in the Molluscan Olfactory Center Specifically Induced by Innately Aversive and In Vitro Aversively Conditioned Odors
AUTHORS:
Kohei Ishida, Momo Murata, Koharu Hashiguchi, Yoshimasa Komatsuzaki, Satoshi Watanabe, Minoru Saito
KEYWORDS:
Land Slug, Olfactory Center, In Vitro Odor-Aversion Conditioning, Spatiotemporal Neural Activity, Fluorescent Voltage Imaging
JOURNAL NAME:
Journal of Behavioral and Brain Science,
Vol.8 No.5,
May
17,
2018
ABSTRACT: In the procerebrum (PC), the olfactory center, of the land slug Limax, an oscillation of local field potential (LFP) with 0.5 - 1 Hz is observed by electrophysiological extracellular recording. The oscillation has a phase delay along the distal-proximal axis, resulting in the propagation of waves from the distal to proximal region. One important advantage of nervous systems of mollusks such as Limax is that their nervous systems in vitro retain several types of computational properties found in vivo (e.g. learning and memory). A previous study showed that the LFP frequency in the PC of Limax increased specifically in response to innately aversive and in vitro aversively conditioned odors. In the present study, we examined spatiotemporal neural activity changes induced in the PC by those odors using the fluorescent voltage imaging technique. The results showed that innately aversive (onion and hexanol) and in vitro aversively conditioned (carrot, which is innately attractive) odors specifically induced an increase in propagation speed of the neural activity in the PC, while innately attractive odors did not induce it. The results also suggested that the avoidance behavior by those odors might be induced by the increase of propagation speed and the following increases in the discharges of the partial nerve that transmits the motor output.