Polarization vision in crayfish motion detectors

Abstract

Motion detector interneurons were examined to determine their responsiveness to the motion of polarized light images (i.e. images segmented by spatial variations in e-vector angle). Computer generated images were displayed as intensity contrasts or polarization contrasts on a modified LCD projection panel. The stimuli included the motion of a single stripe (45 degrees -55 degrees /s) and the global motion of a square wave grating (3.3 degrees /s). Neurons were impaled in the medulla interna. Of the neurons which exhibited a directional response to the motion of intensity contrast stimuli, about 2/3 were also directional in the response to polarized light images. Transient (nondirectional) stimuli included looming and jittery motions. The responses to the transient motions of the polarized light images were roughly comparable to those elicited by intensity contrast. The results imply that behavioral responses to polarized light images (i.e. optokinetic and defense reflexes) may have a basis in the polarization sensitivity and synaptic organization of the medulla interna.

Polarisation signals: a new currency for communication

“…Neuronal responses to polarisation variation, such as angle rotation or varying degree, are indicative of polarisation sensitivity but not necessarily polarisation vision. Electrophysiological data are hard to obtain, compared with indicative photoreceptor structures, but are instructive at every level, from receptors through to processing, to brain and motor output (Labhart and Meyer, 2002;Heinze and Homberg, 2007;Doujak, 1984;Shaw, 1966;Chiou et al, 2008b;Kleinlogel and Marshall, 2006;Moody and Parriss, 1961;Glantz, 1996Glantz, , 2008.…”

Molecular evidence for color discrimination in the Atlantic sand fiddler crab, Uca pugilator

“…However, with only three opsin genes, color vision in all directions probably requires such uniformity of expression. In addition to color discrimination, polarization sensitivity is common in several marine organisms, and its role is similar to color vision in enhancing contrast and conspicuousness, intraspecific signaling, and object identification (Cronin et al, 2003;Glantz and Schroeter, 2006;Glantz, 2008). In fiddler crabs, polarization sensitivity can apparently be used as a celestial direction cue for orienting to the crabs' home beach (Herrnkind, 1968;Chiussi and Diaz, 2002), although it appears to play no role in finer-scale navigation by path integration (Layne et al, 2003).…”

Direction Selective Neurons Responsive to Horizontal Motion in a Crab Reflect an Adaptation to Prevailing Movements in Flat Environments

“…They usually display a relatively small and ipsilateral receptive field, prefer small objects, and display a rapid adaptation on stimulus repetition. Among them are FD cells of blowflies (Egelhaaf, 1985;Warzecha et al, 1993), movement-sensitive neurons of butterflies (Swihart, 1968), DS neurons from hawk-moths (Collett, 1971(Collett, , 1972, DS neurons from crayfish (Glantz, 2008), and MLG1 of crabs (Medan et al, 2007). Other examples are found within small-target-motion detectors (STMD), some of which present direction preference (Gilbert and Strausfeld, 1991;O'Carroll, 1993;Nordström et al, 2006;Barnett et al, 2007;Trischler et al, 2007).…”

“…Other examples are found within small-target-motion detectors (STMD), some of which present direction preference (Gilbert and Strausfeld, 1991;O'Carroll, 1993;Nordström et al, 2006;Barnett et al, 2007;Trischler et al, 2007). Most of this type of cells are described as DS neurons because they display a stronger response in one direction compared with the other, but they lack a proper inhibitory response in the null direction (Wiersma and Yanagisawa, 1971;O'Carroll, 1993;Nordström et al, 2006;Barnett et al, 2007;Medan et al, 2007;Glantz, 2008).…”