title: Fish geometry and electric organ discharge determine functional organization of the electrosensory epithelium.
abstract: Active electroreception in Gymnotus omarorum is a sensory modality that perceives the changes that nearby objects cause in a self generated electric field. The field is emitted as repetitive stereotyped pulses that stimulate skin electroreceptors. Differently from mormyriformes electric fish, gymnotiformes have an electric organ distributed along a large portion of the body, which fires sequentially. As a consequence shape and amplitude of both, the electric field generated and the image of objects, change during the electric pulse. To study how G. omarorum constructs a perceptual representation, we developed a computational model that allows the determination of the self-generated field and the electric image. We verify and use the model as a tool to explore image formation in diverse experimental circumstances. We show how the electric images of objects change in shape as a function of time and position, relative to the fish's body. We propose a theoretical framework about the organization of the different perceptive tasks made by electroreception: 1) At the head region, where the electrosensory mosaic presents an electric fovea, the field polarizing nearby objects is coherent and collimated. This favors the high resolution sampling of images of small objects and perception of electric color. Besides, the high sensitivity of the fovea allows the detection and tracking of large faraway objects in rostral regions. 2) In the trunk and tail region a multiplicity of sources illuminate different regions of the object, allowing the characterization of the shape and position of a large object. In this region, electroreceptors are of a unique type and capacitive detection should be based in the pattern of the afferents response. 3) Far from the fish, active electroreception is not possible but the collimated field is suitable to be used for electrocommunication and detection of large objects at the sides and caudally.
authors.affiliation: Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
authors.forename: Juan Ignacio
authors.initials: JI
authors.lastname: Sanguinetti-Scheck
authors.forename: Eduardo Federico
authors.initials: EF
authors.lastname: Pedraja
authors.forename: Esteban
authors.initials: E
authors.lastname: Cilleruelo
authors.forename: Adriana
authors.initials: A
authors.lastname: Migliaro
authors.forename: Pedro
authors.initials: P
authors.lastname: Aguilera
authors.forename: Angel Ariel
authors.initials: AA
authors.lastname: Caputi
authors.forename: Ruben
authors.initials: R
authors.lastname: Budelli
mesh_terms: D000818:Animals; D004557:Electric Organ / Q000378:metabolism*; D004848:Epithelium / Q000033:anatomy & histology / Q000378:metabolism*; D023702:Gymnotiformes / Q000033:anatomy & histology* / Q000378:metabolism* / Q000502:physiology; D011984:Sensory Receptor Cells / Q000166:cytology / Q000378:metabolism
references.citation: J Physiol Paris. 2002 Sep-Dec;96(5-6):431-44
references.pmid: 14692491
references.citation: J Exp Biol. 2007 Sep;210(Pt 17):3082-95
references.pmid: 17704083
references.citation: J Exp Biol. 2006 Sep;209(Pt 18):3636-51
references.pmid: 16943504
references.citation: Biosystems. 2003 Sep;71(1-2):169-77
references.pmid: 14568217
references.citation: Brain Behav Evol. 1994;44(3):166-74
references.pmid: 7987665
references.citation: J Comput Neurosci. 1995 Jun;2(2):131-47
references.pmid: 8521283
references.citation: J Exp Biol. 2000 Feb;203(Pt 3):481-92
references.pmid: 10637177
references.citation: J Exp Biol. 2003 Mar;206(Pt 6):989-98
references.pmid: 12582141
references.citation: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2006 Jun;192(6):587-600
references.pmid: 16501980
references.citation: J Physiol Paris. 2008 Jul-Nov;102(4-6):256-71
references.pmid: 18992336
references.citation: J Comp Physiol A. 2000-2001;186(12):1185-97
references.pmid: 11288829
references.citation: J Physiol Paris. 2004 Jan-Jun;98(1-3):67-80
references.pmid: 15477023
references.citation: Interdiscip Sci. 2010 Dec;2(4):291-307
references.pmid: 21153776
references.citation: J Exp Biol. 1998 Jul;201(Pt 14):2115-28
references.pmid: 9639586
references.citation: PLoS Comput Biol. 2005 Jul;1(2):123-31
references.pmid: 16110331
references.citation: Curr Opin Neurobiol. 1995 Dec;5(6):769-77
references.pmid: 8805421
references.citation: J Exp Biol. 2009 Nov;212(Pt 21):3478-89
references.pmid: 19837890
references.citation: J Comp Physiol A. 1993 May;172(4):481-91
references.pmid: 8315610
references.citation: Nature. 1998 Oct 29;395(6705):890-4
references.pmid: 9804420
references.citation: PLoS Comput Biol. 2007 Mar 2;3(3):e38
references.pmid: 17335346
references.citation: J Physiol Paris. 2002 Sep-Dec;96(5-6):421-9
references.pmid: 14692490
references.citation: J Exp Biol. 2000 Nov;203(Pt 21):3279-87
references.pmid: 11023848