A neural model of electrosensory system making electrolocation of weakly electric fish

We address the question of how the fish recognizes the location of objects at a given position, independently of the electric properties of objects, a lthough the distortion pattern of electric field is varied depending on the electric property. To know how the electric field generated by fish's elec tric organ discharge (EOD) is spatially and temporally distorted by resisti ve and capacitive objects, we calculated the electric held using a reasonab le model of fish body. P and T electroreceptors distributed on the fish bod y surface respond to the amplitude and phase modulations of EOD, respective ly, and propagate their output signals to electrosensory lateral-line lobe (ELL) and torus semicircularis (Ts), respectively. As the first step to cla rify the neural mechanism of electrolocation, we made a neural network mode l of electrosensory system consisting of electroreceptors, afferent nerves, ELL, and TS, and investigated how the amplitude and phase modulations are encoded in ELL and TS, respectively. (C) 2001 Elsevier Science B.V. All rig hts reserved.