INVESTIGADORES
BERON DE ASTRADA Martin
capítulos de libros
Título:
The visual system of Chasmagnathus granulatus: anatomy and physiology of the optic neuropils that support learning and memory
Autor/es:
D. TOMSIC, M. BERÓN DE ASTRADA, J. SZTARKER, V. MEDAN, D. OLIVA
Libro:
Frontiers in the biology and ecology of estuarine crabs. Chasmagnathus granulatus as a model system
Editorial:
Furg
Referencias:
Año: 2006;
Resumen:
Semiterrestrial crabs possess a highly developed visual system and display conspicuous visual guided behaviors (e.g., Hemmi and Zeil, 2003), however, relatively little is known about the neural organization and cellular morphologies of crustacean optic neuropils. Among decapods, the crayfish is the single taxon from which optic lobe neuroanatomy has been studied in some detail (Strausfeld and Nässel, 1980). Similarly, physiological studies of vision in crustaceans are scant (for a review see Wiersma et al., 1982; Glantz and Miller, 2002). In the crab C. granulatus defined visual cues, such as a bar moving at a certain speed across the upper visual field, elicit directional escape responses that have been interpreted as antipredatory (Tomsic et al., 1993). However, these responses are modifiable in that following repetitive presentation of the visual stimulus the response declines and remains reduced for several days (for a review see Maldonado, 2002;  and chapter 1 in this section). Recent investigations demonstrated that the behavioral change is the result of a rather complex form of memory determined by an association between the moving stimulus and the context in which the stimulus occurs (Tomsic et al., 1998). The ability of C. granulatus to modify the response to certain visual stimuli has been interpreted as an adaptation to the conditions of its natural environment (Tomsic et al., 1993; Eckert and Zeil, 2001). The current chapter first describes the anatomical organization of the optic lobe of C. granulatus together with the neural architecture of the visual neuropils; and second describes the physiological characterization of a number of neuronal elements that support the visual abilities of the crab, including learning and memory. Detailed descriptions of these themes have been provided elsewhere (Berón de Astrada et al., 2001; Berón de Astrada and Tomsic, 2002; Tomsic, 2002; Tomsic et al., 2003; Sztarker and Tomsic 2004; Sztarker et al., 2005).