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Perception of objects in weakly electric fish Gymnotus carapo as studied in recordings from rhombencephalic neurons

Perception of objects in weakly electric fish Gymnotus carapo as studied in recordings from... 221 18 18 4 4 Dr. Peter A. Schlegel Centre d'Etudes de Physiologie Nerveuse, C.N.R.S. Paris France Laboratoire de Physiologie Nerveuse Groupe de Laboratoires du C.N.R.S. 91190 Gif sur Yvette France Summary 1. Activities of single units related to the electrosensitive system of the weakly electric fish Gymnotus carapo (Gymnotidae) were recorded from the lateral lobe (rhombencephalon) and the cerebellum. 2. Most lateral lobe units showed phase-locked responses to artificial electric pulses (30–50 cycles/s) imitating the fish's electric organ discharge (EOD). Other units, however, displayed random activity which became phase-locked under certain stimulus conditions. 3. When conductive (metal) or non-conductive (plastic) objects were placed at different positions along the fish's trunc, both types of responses were modulated (phasically and tonically). Metal and plastic had opposite effects at the same position. 4. The responses of certain units depended upon the direction and velocity of the movement of the object. In other units, a significant modulation of the responses was only obtained when the velocity exceded 3–5 cm/s. A few units responded only when objects (metal and/or plastic) were presented at certain positions. 5. The change in stimulus frequency influenced the response, i. e. the number of impulses per second and their phase relation to the stimulus pulses. The most adequate frequency to excite lateral lobe units was close to the EOD frequency of the resting fish. 6. Spontaneously active units in the cerebellum showed similar properties to lateral lobe units, as far as the activity modulation by objects is concerned. In contrast, there was no phase-locking in any case. The average firing frequency of some of these units was not influenced by varying the stimulus frequency (from 0 to 1000 cps) whereas, the degree of modulation caused by field disturbing objects varied with stimulus frequency. The most adequate frequency ranged between 30–100 csp. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Experimental Brain Research Springer Journals

Perception of objects in weakly electric fish Gymnotus carapo as studied in recordings from rhombencephalic neurons

Experimental Brain Research , Volume 18 (4) – Nov 1, 1973

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References (17)

Publisher
Springer Journals
Copyright
Copyright © 1973 by Springer-Verlag
Subject
Biomedicine; Neurosciences; Neurology
ISSN
0014-4819
eISSN
1432-1106
DOI
10.1007/BF00239104
Publisher site
See Article on Publisher Site

Abstract

221 18 18 4 4 Dr. Peter A. Schlegel Centre d'Etudes de Physiologie Nerveuse, C.N.R.S. Paris France Laboratoire de Physiologie Nerveuse Groupe de Laboratoires du C.N.R.S. 91190 Gif sur Yvette France Summary 1. Activities of single units related to the electrosensitive system of the weakly electric fish Gymnotus carapo (Gymnotidae) were recorded from the lateral lobe (rhombencephalon) and the cerebellum. 2. Most lateral lobe units showed phase-locked responses to artificial electric pulses (30–50 cycles/s) imitating the fish's electric organ discharge (EOD). Other units, however, displayed random activity which became phase-locked under certain stimulus conditions. 3. When conductive (metal) or non-conductive (plastic) objects were placed at different positions along the fish's trunc, both types of responses were modulated (phasically and tonically). Metal and plastic had opposite effects at the same position. 4. The responses of certain units depended upon the direction and velocity of the movement of the object. In other units, a significant modulation of the responses was only obtained when the velocity exceded 3–5 cm/s. A few units responded only when objects (metal and/or plastic) were presented at certain positions. 5. The change in stimulus frequency influenced the response, i. e. the number of impulses per second and their phase relation to the stimulus pulses. The most adequate frequency to excite lateral lobe units was close to the EOD frequency of the resting fish. 6. Spontaneously active units in the cerebellum showed similar properties to lateral lobe units, as far as the activity modulation by objects is concerned. In contrast, there was no phase-locking in any case. The average firing frequency of some of these units was not influenced by varying the stimulus frequency (from 0 to 1000 cps) whereas, the degree of modulation caused by field disturbing objects varied with stimulus frequency. The most adequate frequency ranged between 30–100 csp.

Journal

Experimental Brain ResearchSpringer Journals

Published: Nov 1, 1973

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