scholarly journals Extraocular sensitivity to polarized light in an echinoderm.

1994 ◽  
Vol 195 (1) ◽  
pp. 281-291 ◽  
Author(s):  
S Johnsen
Keyword(s):  
Polarized Light ◽  
Individual Preference ◽  
Polarization Sensitivity ◽  
Unpolarized Light ◽  
Orientation Experiment

This study tests the hypotheses that the birefringent calcite and stereom structure of the brittlestar (Ophiuroidea, Echinodermata) endoskeleton polarizes light and that certain brittlestars respond to polarized light. The first hypothesis was tested in Ophioderma brevispinum by examining ossicles from freshly killed specimens under polarized light. This analysis revealed that the lateral arm shields, oral arm shields, arm spines and aboral disk ossicles are dichroic and thus polarize light. The second hypothesis was tested in two orientation experiments under polarized light. The results from the first orientation experiment showed (1) that, under polarized light, animals oriented significantly and unimodally, (2) that, under polarized light with the e-vector perpendicular to that in 1, animals oriented significantly and unimodally to within 18 degrees of the bearing of the animals in 1, and (3) that, under unpolarized light, animals did not orient significantly. The results from the second orientation experiment showed that, under polarized light, animals oriented significantly and unimodally to within 17 degrees of an individual preference previously established under polarized light; but under unpolarized light, animals did not orient significantly to an individual preference established under polarized light. Thus, O. brevispinum orients under polarized, but not unpolarized, light. The unimodal orientation and lack of consistent alignment with the e-vector suggest that polarized light is not used as a directional cue but instead as a signal to sustain oriented behavior. The dichroism of the ossicles of O. brevispinum and the animal's capacity (though eyeless) to discriminate between polarized and unpolarized light suggest that the mechanism of polarization sensitivity may rely on polarizing filters built from the animal's skeleton.

scholarly journals No evidence for polarization sensitivity in the pigeon electroretinogram

1995 ◽  
Vol 198 (2) ◽  
pp. 325-335 ◽  
Author(s):  
J J Vos Hzn ◽  
M A J M Coemans ◽  
J F W Nuboer
Keyword(s):  
White Light ◽  
Monochromatic Light ◽  
Polarized Light ◽  
Polarization Sensitivity ◽  
Slow Rotation ◽  
Unpolarized Light ◽  
Linearly Polarized

The electroretinographical response to flashes of linearly polarized light directed at the pigeon's yellow field was compared with that to flashes of unpolarized light. This was carried out for white light and for monochromatic light of various wavelengths, including ultraviolet. In addition, responses to slow rotation of the E-vector of polarized light were measured. Neither the presence or absence of polarization, nor the orientation of the E-vector, influenced any of the electrophysiological variables that were monitored in these experiments.

scholarly journals Ultraviolet polarization vision in fishes: possible mechanisms for coding e–vector

2000 ◽  
Vol 355 (1401) ◽  
pp. 1187-1190 ◽  
Author(s):  
Craig W. Hawryshyn
Keyword(s):  
Polarized Light ◽  
Spatial Arrangement ◽  
Short Review ◽  
Research Problem ◽  
Polarization Sensitivity ◽  
Polarization Vision ◽  
Selective Reflection ◽  
Mosaic Pattern ◽  
Cone Mosaic ◽  
Biophysical Mechanism

Polarization vision in vertebrates has been marked with significant controversy over recent decades. In the last decade, however, models from two laboratories have indicated that the spatial arrangement of photoreceptors provides the basis for polarization sensitivity.Work in my laboratory, in collaboration with I. Novales Flamarique and F. I. Harosi, has shown that polarization sensitivity depends on a well–defined square cone mosaic pattern and that the biophysical properties of the square cone mosaic probably account for polarization vision in the ultraviolet spectrum. The biophysical mechanism appears to be based on the selective reflection of axial–polarized light by the partitioning membrane, formed along the contact zone between the members of the double cones, onto neighbouring ultraviolet–sensitive cones. In this short review, I discuss the historical development of this research problem.

Conversion of unpolarized light to polarized light with greater than 50% efficiency by photorefractive two-beam coupling

2000 ◽  
Vol 25 (4) ◽  
pp. 257 ◽  
Author(s):  
John E. Heebner ◽  
Ryan S. Bennink ◽  
Robert W. Boyd ◽  
R. A. Fisher
Keyword(s):  
Polarized Light ◽  
Unpolarized Light ◽  
Beam Coupling

Polarization analysis in the crayfish visual system

2001 ◽  
Vol 204 (14) ◽  
pp. 2383-2390 ◽  
Author(s):  
Raymon M. Glantz
Keyword(s):  
Visual System ◽  
Motor Neurons ◽  
Polarized Light ◽  
Cell Types ◽  
Afferent Input ◽  
Polarization Sensitivity ◽  
Polarization Analysis ◽  
Low Contrast ◽  
Motion Responses ◽  
Light Flashes

SUMMARY It is proposed that polarization sensitivity at the most peripheral stages of the crayfish visual system (lamina ganglionaris and medulla externa) is used to enhance contrast and thus may contribute to motion detection in low contrast environments. The four classes of visual interneurons that exhibit polarization sensitivity (lamina monopolar cells, tangential cells, sustaining fibers and dimming fibers) are not sensitive exclusively to polarized light but also respond to unpolarized contrast stimuli. Furthermore, many of these cells and the sustaining fibers in particular exhibit a greater differential e-vector responsiveness to a changing e-vector than to e-vector variations among steady-state stimuli. While all four cell types respond modestly to light flashes at an e-vector of 90° to the preferred orientation, the dynamic response to a changing e-vector is small or absent at this orientation. Because the sustaining fibers exhibit polarization sensitivity, and they provide afferent input to a subset of optomotor neurons, the latter were also tested for polarization sensitivity. The optomotor neurons involved in compensatory reflexes for body pitch were differentially sensitive to the e-vector angle of a flash of light, with maximum responses for e-vectors near the vertical. The motor neurons also exhibited a maximum response near the vertical e-vector to a continuously rotating polarizer. Two scenarios are described in which the sensitivity to a changing e-vector can produce motion responses in the absence of intensity contrast.

scholarly journals Optimization ofs-Polarization Sensitivity in Apertureless Near-Field Optical Microscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yuika Saito ◽  
Yoshiro Ohashi ◽  
Prabhat Verma
Keyword(s):  
Spatial Resolution ◽  
Rayleigh Scattering ◽  
Incident Light ◽  
Near Field ◽  
Polarized Light ◽  
Polarization Sensitivity ◽  
Experimental Setup ◽  
Experimental Conditions ◽  
General Belief ◽  
Polarization Configuration

It is a general belief in apertureless near-field microscopy that the so-calledp-polarization configuration, where the incident light is polarized parallel to the axis of the probe, is advantageous to its counterpart, thes-polarization configuration, where the incident light is polarized perpendicular to the probe axis. While this is true for most samples under common near-field experimental conditions, there are samples which respond better to thes-polarization configuration due to their orientations. Indeed, there have been several reports that have discussed such samples. This leads us to an important requirement that the near-field experimental setup should be equipped with proper sensitivity for measurements withs-polarization configuration. This requires not only creation of effective s-polarized illumination at the near-field probe, but also proper enhancement of s-polarized light by the probe. In this paper, we have examined thes-polarization enhancement sensitivity of near-field probes by measuring and evaluating the near-field Rayleigh scattering images constructed by a variety of probes. We found that thes-polarization enhancement sensitivity strongly depends on the sharpness of the apex of near-field probes. We have discussed the efficient value of probe sharpness by considering a balance between the enhancement and the spatial resolution, both of which are essential requirements of apertureless near-field microscopy.

Shade-seeking behaviour under polarized light by the brittlestar Ophioderma Brevispinum (Echinodermata: Ophiuroidea)

1999 ◽  
Vol 79 (4) ◽  
pp. 761-763 ◽  
Author(s):  
Sönke Johnsen ◽  
William M. Kier
Keyword(s):  
Ultraviolet Radiation ◽  
Random Distribution ◽  
Polarized Light ◽  
Solar Ultraviolet Radiation ◽  
Unpolarized Light ◽  
Linearly Polarized ◽  
Solar Ultraviolet ◽  
Marine Laboratory

The effect of polarized light on the shade-seeking behaviour of the ophiuroid Ophioderma brevispinum was investigated at the Keys Marine Laboratory, Long Key, Florida, USA. Animals were collected and placed in a partially shaded arena. When the arena was illuminated with unpolarized light, the number of animals settling under the shaded portion of the arena was not significantly different from random (N=30, P>0.3). When the arena was illuminated with linearly polarized light, the number of animals settling in the shaded portion of the arena was approximately double what would be expected in a random distribution (N=30, P<0.001). The results are further evidence that O. brevispinum is sensitive to polarized light and are consistent with the hypothesis that polarized light may be used by the animals as an indicator of harmful levels of solar ultraviolet radiation.

scholarly journals An unsuccessful attempt to elicit orientation responses to linearly polarized light in hatchling loggerhead sea turtles ( Caretta caretta )

2011 ◽  
Vol 366 (1565) ◽  
pp. 757-762 ◽  
Author(s):  
Lydia M. Mäthger ◽  
Kenneth J. Lohmann ◽  
Colin J. Limpus ◽  
Kerstin A. Fritsches
Keyword(s):  
Light Field ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Sea Turtles ◽  
Polarized Light ◽  
Caretta Caretta ◽  
Polarization Sensitivity ◽  
Light Perception ◽  
Unsuccessful Attempt ◽  
Swimming Direction

Sea turtles undertake long migrations in the open ocean, during which they rely at least partly on magnetic cues for navigation. In principle, sensitivity to polarized light might be an additional sensory capability that aids navigation. Furthermore, polarization sensitivity has been linked to ultraviolet (UV) light perception which is present in sea turtles. Here, we tested the ability of hatchling loggerheads ( Caretta caretta ) to maintain a swimming direction in the presence of broad-spectrum polarized light. At the start of each trial, hatchling turtles, with their magnetic sense temporarily impaired by magnets, successfully established a steady course towards a light-emitting diode (LED) light source while the polarized light field was present. When the LED was removed, however, hatchlings failed to maintain a steady swimming direction, even though the polarized light field remained. Our results have failed to provide evidence for polarized light perception in young sea turtles and suggest that alternative cues guide the initial migration offshore.

scholarly journals Behavioural relevance of polarization sensitivity as a target detection mechanism in cephalopods and fishes

2011 ◽  
Vol 366 (1565) ◽  
pp. 734-741 ◽  
Author(s):  
Vincenzo Pignatelli ◽  
Shelby E. Temple ◽  
Tsyr-Huei Chiou ◽  
Nicholas W. Roberts ◽  
Shaun P. Collin ◽  
...  
Keyword(s):  
Target Detection ◽  
Polarized Light ◽  
Luminance Contrast ◽  
Polarization Sensitivity ◽  
Prey Detection ◽  
Free Swimming ◽  
Detection Mechanism ◽  
Set Up ◽  
Polarization Of Light

Aquatic habitats are rich in polarized patterns that could provide valuable information about the environment to an animal with a visual system sensitive to polarization of light. Both cephalopods and fishes have been shown to behaviourally respond to polarized light cues, suggesting that polarization sensitivity (PS) may play a role in improving target detection and/or navigation/orientation. However, while there is general agreement concerning the presence of PS in cephalopods and some fish species, its functional significance remains uncertain. Testing the role of PS in predator or prey detection seems an excellent paradigm with which to study the contribution of PS to the sensory assets of both groups, because such behaviours are critical to survival. We developed a novel experimental set-up to deliver computer-generated, controllable, polarized stimuli to free-swimming cephalopods and fishes with which we tested the behavioural relevance of PS using stimuli that evoke innate responses (such as an escape response from a looming stimulus and a pursuing behaviour of a small prey-like stimulus). We report consistent responses of cephalopods to looming stimuli presented in polarization and luminance contrast; however, none of the fishes tested responded to either the looming or the prey-like stimuli when presented in polarization contrast.

Polarization vision in cuttlefish in a concealed communication channel?

1996 ◽  
Vol 199 (9) ◽  
pp. 2077-2084
Author(s):  
N Shashar ◽  
P Rutledge ◽  
T Cronin
Keyword(s):  
Polarized Light ◽  
Egg Laying ◽  
Polarization Sensitivity ◽  
Polarization Vision ◽  
Microscopical Examination ◽  
Polarization Pattern ◽  
Behavioral Experiments ◽  
Marine Animals ◽  
Linearly Polarized ◽  
Electron Microscopical

Polarization sensitivity is well documented in marine animals, but its function is not yet well understood. Of the cephalopods, squid and octopus are known to be sensitive to the orientation of polarization of incoming light. This sensitivity arises from the orthogonal orientation of neighboring photoreceptors. Electron microscopical examination of the retina of the cuttlefish Sepia officinalis L. revealed the same orthogonal structure, suggesting that cuttlefish are also sensitive to linearly polarized light. Viewing cuttlefish through an imaging polarized light analyzer revealed a prominent polarization pattern on the arms, around the eyes and on the forehead of the animals. The polarization pattern disappeared when individuals lay camouflaged on the bottom and also during extreme aggression display, attacks on prey, copulation and egg-laying behavior in females. In behavioral experiments, the responses of cuttlefish to their images reflected from a mirror changed when the polarization patterns of the reflected images were distorted. These results suggest that cuttlefish use polarization vision and display for intraspecific recognition and communication.

Two-Channel Polarization Analyzer in the Sustaining Fiber-Dimming Fiber Ensemble of Crayfish Visual System

1998 ◽  
Vol 80 (5) ◽  
pp. 2571-2583 ◽  
Author(s):  
Raymon M. Glantz ◽  
Andy McIsaac
Keyword(s):  
Visual System ◽  
Polarized Light ◽  
Polarization Sensitivity ◽  
Visual Responses ◽  
Polarization Analyzer ◽  
Peripheral Neurons ◽  
Steady State Responses ◽  
Vector Orientation ◽  
Channel Polarization ◽  
State Responses

Glantz, Raymon M. and Andy McIsaac. Two-channel polarization analyzer in the sustaining fiber-dimming fiber ensemble of crayfish visual system. J. Neurophysiol. 80: 2571–2583, 1998. Polarization sensitivity (PS) was examined in two classes of neurons, sustaining fibers and dimming fibers, in the medulla externa (second optic neuropile) of the crayfish, Pacifasticus leniusculus. Visual responses were recorded intracellularly and extracellularly. The influence of e-vector orientation (θ) was probed in steady-state responses, with brief flashes and with a rotating polarizer. The results indicate that the entire sustaining fiber population appears to be maximally sensitive to vertically polarized light. Although the evidence is less complete for dimming fibers, they appear to be maximally inhibited by vertically polarized light and excited by horizontally polarized light. Thus the sustaining fibers and dimming fibers form a two-channel polarization analyzer that captures the main features of the polarization system established in photoreceptors and lamina monopolar cells. The available evidence suggests that this two-channel system has the same characteristics across most or all of the retinula. Lateral inhibition in sustaining fibers is differentially sensitive to θ. Inhibition is substantial at θ = 90° (horizontal) and essentially absent at θ = 0°. The details of the sustaining fiber polarization response closely follow features established in more peripheral neurons, including the magnitude of PS, enhanced responsiveness to a changing e-vector, and modest directionality to a changing e-vector in∼40% of the cells.

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