A neural mechanism of hyperaccurate detection of phase advance and delay in the jamming avoidance response of weakly electric fish |
| |
Authors: | Kashimori Y Inoue S Kambara T |
| |
Institution: | (1) Division of Bioinformatics, Department of Applied Physics and Chemistry, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan, JP;(2) Department of Information Network Science, Graduate School of Information Systems, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan, JP |
| |
Abstract: | The weakly electric fish Eigenmannia can detect the phase difference between a jamming signal and its own signal down to 1 s. To clarify the neuronal mechanism of this hyperaccurate detection of phase difference, we present a neural network model
of the torus of the midbrain which plays an essential role in the detection of phase advances and delays. The small-cell model
functions as a coincidence detector and can discriminate a time difference of more than 100 s. The torus model consists of laminae 6 and 8. The model of lamina 6 is made with multiple encoding units, each of which
consists of a single linear array of small cells and a single giant cell. The encoding unit encodes the phase difference into
its spatio-temporal firing pattern. The spatially random distribution of small cells in each encoding unit improves the encoding
ability of phase modulation. The neurons in lamina 8 can discriminate the phase advance and delay of jamming electric organ
discharges (EODs) compared with the phase of the fish's own EOD by integrating simultaneously the outputs from multiple encoding
units in lamina 6. The discrimination accuracy of the feature-detection neurons is of the order of 1 s. The neuronal mechanism generating this hyperacuity arises from the spatial feature of the system that the innervation sites
of small cells in different encoding units are distributed randomly and differently on the dendrites of single feature-detection
neurons. The mechanism is similar to that of noise-enhanced information transmission.
Received: 10 July 2000 / Accepted in revised form: 19 January 2001 |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|