Document Detail


Waveform diversity of electric organ discharges: the role of electric organ auto-excitability in Gymnotus spp.
MedLine Citation:
PMID:  19837890     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This article shows that differences in the waveforms of the electric organ discharges (EODs) from two taxa are due to the different responsiveness of their electric organs (EOs) to their previous activity (auto-excitability). We compared Gymnotus omarorum endemic to Uruguay (35 degrees South, near a big estuary), which has four components in the head to tail electric field (V(1) to V(4)), with Gymnotus sp. endemic to the south of Brazil, Paraguay and Argentinean Mesopotamia (25 degrees South, inland), which shows a fifth component in addition to the others (V(5)). We found that: (a) the innervation pattern of the electrocytes, (b) the three earlier, neurally driven, EOD components (V(1) to V(3)), and (c) their remnants after curarisation were almost identical in the two taxa. The equivalent electromotive forces of late components (V(4) and V(5)) increased consistently as a function of the external current associated with the preceding component and were abolished by partial curarisation in both taxa. Taken together these data suggest that these components are originated in the responses of the electrocytes to longitudinal currents through the EO. By using a differential load procedure we showed that V(4) in G. omarorum responded to experimental changes in its excitation current with larger amplitude variations than V(4) in Gymnotus sp. We conclude that the differences in the EOD phenotype of the two studied taxa are due to the different EO auto-excitability. This, in turn, is caused either by the different expression of a genetic repertoire of conductance in the electrocyte membrane or in the wall of the tubes forming the EO.
Authors:
Alejo Rodr??guez-Catt??neo; Angel Ariel Caputi
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  The Journal of experimental biology     Volume:  212     ISSN:  1477-9145     ISO Abbreviation:  J. Exp. Biol.     Publication Date:  2009 Nov 
Date Detail:
Created Date:  2009-10-19     Completed Date:  2010-01-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0243705     Medline TA:  J Exp Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  3478-89     Citation Subset:  IM    
Affiliation:
Departamento de Neurociencias Integrativas y Computacionales, Instituto de Investigaciones Biol??gicas Clemente Estable, Montevideo, Uruguay, Av. Italia 3318, Montevideo, Uruguay.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animal Communication
Animals
Electric Conductivity
Electric Organ* / anatomy & histology,  physiology
Electrophysiology
Gymnotiformes / anatomy & histology*,  classification,  physiology*
Phenotype
South America

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Radio frequency magnetic fields disrupt magnetoreception in American cockroach.
Next Document:  Kinematics of suction feeding in the seahorse Hippocampus reidi.