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Electric organ discharges and electric images during electrolocationWeakly electric fish use active electrolocation - the generation and detection of electric currents - to explore their surroundings. Although electrosensory systems include some of the most extensively understood circuits in the vertebrate central nervous system, relatively little is known quantitatively about how fish electrolocate objects. We believe a prerequisite to understanding electrolocation and its underlying neural substrates is to quantify and visualize the peripheral electrosensory information measured by the electroreceptors. We have therefore focused on reconstructing both the electric organ discharges (EODs) and the electric images resulting from nearby objects and the fish's exploratory behaviors. Here, we review results from a combination of techniques, including field measurements, numerical and semi-analytical simulations, and video imaging of behaviors. EOD maps are presented and interpreted for six gymnotiform species. They reveal diverse electric field patterns that have significant implications for both the electrosensory and electromotor systems. Our simulations generated predictions of the electric images from nearby objects as well as sequences of electric images during exploratory behaviors. These methods are leading to the identification of image features and computational algorithms that could reliably encode electrosensory information and may help guide electrophysiological experiments exploring the neural basis of electrolocation.
Document ID
Document Type
Reprint (Version printed in journal)
Assad, C.
(California Institute of Technology Pasadena, CA 91125, United States)
Rasnow, B.
Stoddard, P. K.
Date Acquired
August 22, 2013
Publication Date
May 1, 1999
Publication Information
Publication: The Journal of experimental biology
Volume: 202 ( Pt 10)
ISSN: 0022-0949
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
Review, Tutorial

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