Electrolocation and electrocommunication in pulse gymnotids: signal carriers, pre-receptor mechanisms and the electrosensory mosaic.
Constraints introduced by signal carriers, pre-receptor mechanisms and receptor transduction are fundamental for shaping the signals used by the brain to build up perceptual images. This review analyses some of these constraints in the electrosensory system of pulse Gymnotids. First, it describes the characteristics and differences of electrolocation and electrocommunication carriers. Second, it analyses the role of electrogenic and non-electrogenic tissues of the fish body in the generation and conditioning of these carriers. Two pre-receptor mechanisms are discussed: (a) the funneling of currents to the perioral region and (b) a Mexican-hat profile involved in edge detection. Finally, some characteristics of the electroreceptor structure and the sensory mosaic are examined. We conclude that there is an electrosensory fovea at the perioral region where a large density and variety of receptors is stimulated by self- and conspecific-generated currents funneled there by non electrogenic tissues. Differences in carrier waveform may be used to distinguish between reafferent and communication signals.
Caputi
Angel A
AA
Departmento de Neurofisiología Comparada y Departamento de Neuroanatomía Comparada, Unidad Asociada a Facultad de Ciencias, Instituto de Investigaciones Biológicas Clemente Estable, Av. Italia 3318, Montevideo, Uruguay. angel@iibce.edu.uy
Castelló
María E
ME
Aguilera
Pedro
P
Trujillo-Cenóz
Omar
O
D000200:Action Potentials / Q000502:physiology; D000819:Animal Communication; D000818:Animals; D004557:Electric Organ / Q000502:physiology*; D023702:Gymnotiformes / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology