Neuronal elementes and organization of the lamina of a highly visual semiterrestrial crab as revealed by Golgi analysis

JULIETA SZTARKER, DANIEL TOMSIC

Vancouver, Canada

Congreso; Eighth International Congress of Neuroethology; 2007

International Sosciety of Neuroethology

Compared with insects, relatively little is known about the neural organization and cell morphologies of crustacean optic neuropils. Although the overall organization of the visual nervous system can be safely generalized among decapod species, and to considerable extent even between decapods and insects, the assumption of perfect matching between the cellular elements that compose the neuropils of different species is not justified. In insects, differences in habitats and lifestyles between species are often correlated with variation in neuronal shapes, connectivity and even cell types (e.g. in the bee, Greiner et al, 2004). Whether this is also the case in decapods is unclear. Information available in the literature suggests that regardless of their different ecologies, the laminas from different species are composed of conserved cell types (Strausfeld and Nässel, 1980; Elofsson and Hagberg, 1986). But the species included in these studies are few and most of them are aquatic, i.e. species in witch vision is not necessarily the most important sensory modality. Here we describe the cellular elements of the lamina of a higly visual semiterrestrial crab, as revealed by Golgi staining. The crab we studied, Chasmagnatus granulathus, belongs to the grapsid family, which members are known to be much more sensitive and reactive to visual stimuli that the most studied of decapods, the crayfish. Based on our results and those from the literature, we discuss the significance of commonalities and differences across taxa with respect to cell types, shapes and connectivity within the lamina.