The formation of myeloid bodies in retinular cells of the pupal compound eyes of silkworm moths (Bombyx mori) exposed to a constant bright light

1991 ◽  
Vol 265 (2) ◽  
pp. 381-384 ◽  
Author(s):  
Eisuke Eguchi ◽  
Shihoko Maeda ◽  
Isamu Shimizu
Keyword(s):  
Bombyx Mori ◽  
Bright Light ◽  
Compound Eyes ◽  
Myeloid Bodies ◽  
Retinular Cells

scholarly journals Neuromuscular systems in the fifth instar larva of silkworm Bombyx mori (Lepidoptera: Bombycidae): I-Cephalothoracic musculature and its innervation

2009 ◽  
Vol 1 (2) ◽  
pp. 201-209
Author(s):  
S. Sivaprasad ◽  
P. Muralimohan
Keyword(s):  
Bombyx Mori ◽  
Instar Larva ◽  
Compound Eyes ◽  
Suboesophageal Ganglion ◽  
Ventral Region ◽  
Thoracic Ganglia ◽  
Neuromuscular Systems ◽  
Frontal Ganglion ◽  
The Brain ◽  
Silkworm Bombyx Mori

The cephalo-thoracic musculature of the fifth instar larva of Bombyx mori comprises distinct groups of segmental muscle bands arranged in a stereotyped pattern. It includes dorsal, ventral, tergopleural, tergocoxal, lateral intersegmental, pleurosternal, sternocoxal, pleurocoxal and spiracular muscles. The cephalothoracic segments are innervated by the nerves of brain, suboesophageal ganglion (SG) and three thoracic ganglia (TG1, TG2, TG3).The brain gives nerves for compound eyes, antennae, labrum, frontal ganglion and the integument in the head. The SG, TG1,TG2,and TG3 give out a pair of lateral segmental nerves each, called the dorsal (DN) and ventral (VN) nerves. The DN of SG innervates muscles in the cephalic region, while its VN innervates muscles in the prothorax. The DN of thoracic ganglia innervates muscles in the dorsal, lateral and ventral regions of the hemi-segment while the VN innervates muscles in the ventral region. The innervation pattern indicates the presence of mixed nerves and multiple innervations that facilitate coordinated body movements and locomotion.

scholarly journals Localization of the Violet and Yellow Receptor Cells in the Crayfish Retinula

1973 ◽  
Vol 62 (4) ◽  
pp. 355-374 ◽  
Author(s):  
Eisuke Eguchi ◽  
Talbot H. Waterman ◽  
Jiro Akiyama
Keyword(s):  
Light Adaptation ◽  
Selective Adaptation ◽  
Compound Eyes ◽  
Intracellular Recordings ◽  
Intercellular Coupling ◽  
Retinular Cell ◽  
Particle Distributions ◽  
Wavelength Sensitivity ◽  
Retinal Distribution ◽  
Retinular Cells

Cellular identification of color receptors in crayfish compound eyes has been made by selective adaptation at 450 nm and 570 nm, wavelengths near the λmax's of the two retinular cell classes previously demonstrated. By utilizing earlier evidence, the concentration of lysosome-related bodies (LRB) was used to measure relative light adaptation and thus wavelength sensitivity in 665 retinular cells from six eyes. The observed particle distributions demonstrate the following. Both violet and yellow receptors occur ordinarily in each retinula. Of the seven regular retinular cells two (R3 and R4 using Eguchi's numbering [1965]) have mean sensitivities significantly greater to violet and less to yellow than the other five. The latter apparently comprise "pure" yellow receptors (R1 and R7) and mixed yellow and violet receptors (R2, R5, and R6). Explanations of such ambiguity requiring two visual pigments in single retinular cells or intercellular coupling of adjacent neuroreceptors are apparently precluded by previous evidence. Present data imply alternatively some positional variability in the violet pair's location in individual retinulas. Thus R3 and R4 are predominantly the violet receptors but in some retinulas R2 and R3 or R4 and R5 (or rarely some other cell pairs) may be. The retinal distribution of such variations has yet to be determined. In agreement with intracellular recordings the blue and yellow cells here identified belong to both the vertical and horizontal e-vector sensitive channels.

Possible role of the central retinular cells in the ommatidia of male black flies (Diptera: Simuliidae)

1987 ◽  
Vol 65 (12) ◽  
pp. 3186-3188 ◽  
Author(s):  
Susan B. McIver ◽  
Gail E. O'Grady
Keyword(s):  
Sensory Receptor ◽  
Compound Eyes ◽  
Black Flies ◽  
Dorsal Region ◽  
Blue Range ◽  
Retinular Cells ◽  
Dioptric Apparatus ◽  
Receptor Layer ◽  
Swarm Formation

In Cnephia dacotensis, a species that mates on rocks and plants without swarm formation, the eyes of the males are separate and undivided. Each ommatidium consists of two general regions: a distal dioptric apparatus and a sensory receptor layer with eight retinular cells. Six of these cells (R1–6) are located peripherally and two centrally; R7 occurs distally and R8 basally. In males of previously studied species in which females are detected as they fly above a male swarm, the compound eyes are holoptic and divided into distinct dorsal and ventral regions. Ommatidia in the dorsal region lack the R7 cell. If in black flies R7 is a blue receptor and R8 a uv receptor, then the absence of R7 means that swarm-forming males see the females against a background that provides a sharper contrast than a background of a uv to blue range. This would sharpen the visibility of the dark female against the background skylight, enabling the male to perceive her more swiftly.

scholarly journals Changes in the structure and pigmentation of the eyes of honeybee (Apis mellifera L.) queens with the "limão" mutation

2000 ◽  
Vol 23 (1) ◽  
pp. 93-96 ◽  
Author(s):  
José Chaud-Netto ◽  
Carminda da Cruz-Landim
Keyword(s):  
Apis Mellifera ◽  
Morphological Changes ◽  
Compound Eyes ◽  
Ultrastructural Organization ◽  
Multivesicular Bodies ◽  
Electron Dense Material ◽  
Eye Color ◽  
Receptor Cells ◽  
Pigment Granules ◽  
Retinular Cells

This study describes the ultrastructural differences between the compound eyes of ch li/ch li and Ch/ch li honeybee queens. Heterozygous "limão" bees had an almost normal ultrastructural organization of the ommatidia, but there were some alterations, including small vacuoles in the crystalline cones and a loss of pigment by primary pigmentary cells. In homozygous bees many ommatidia had very deformed crystalline cones and there were some bipartite rhabdoma. There was a reduction in the amount of pigment in the primary and secondary pigmentary cells and receptor cells (retinulae) of mutant eyes. However, the eyes of both heterozygous and homozygous queens had the same type of pigment granules. Certain membrane-limited structures containing pigment granules and electron-dense material appeared to be of lysosomal nature. Since these structures occurred in the retinular cells of mutant eyes, they were considered to be multivesicular bodies responsible for the reduction in rhabdom volume in the presence of light, as a type of adaptation to brightness. The reduction of pigment in the pigmentary and retinular cells and the morphological changes seen in the rhabdom of the ommatidia may originate visual deficiencies, which could explain the behavioral modifications reported for Apis mellifera queens with mutant eye color.

The compound eyes of mantis shrimps (Crustacea, Hoplocarida, Stomatopoda). I. Compound eye structure: the detection of polarized light

1991 ◽  
Vol 334 (1269) ◽  
pp. 33-56 ◽  
Keyword(s):  
Compound Eye ◽  
Polarized Light ◽  
Structural Features ◽  
Polarization Sensitivity ◽  
Compound Eyes ◽  
Visual Tasks ◽  
Retinular Cells ◽  
High Degree ◽  
Structural Adaptations ◽  
Parallel Sampling

Stomatopod crustaceans possess compound eyes divided into three distinct regions: two peripheral retinae - the dorsal and ventral hemispheres — and the mid-band. Throughout the eye, in particular in the midband, there are many structural adaptations that potentially enable different portions of the eye to perform different visual tasks. A high degree of optical overlap between these eye regions allows the parallel sampling of various parameters of light from one direction in space. In consecutive papers, we present structural evidence that stomatopods have the receptors necessary for colour and polarization vision. The first paper describes the retinal structures that suggest the existence of polarization sensitivity in stomatopods. mid-band rows five and six, together with the hemispheres, are probably involved in this visual process. By using two strategies, rhabdomal modification and varying the orientation of similar ommatidial units in the three eye regions, stomatopods have the capacity to analyse polarized light in a very detailed manner. All the species included in this study live in shallow, tropical waters where polarized light signals are abundant. It therefore seems likely that their eyes have evolved to take advantage of such environmental cues. Structural evidence also suggests that all retinular cells in rows one to four of the mid-band, and the distal most retinular cells (R8) over most of the retina, are not sensitive to polarized light. These mid-band rows are instead adapted for colour detection. This function of the stomatopod retina and structural features concerned with colour sensitivity are described in paper II ( Phil. Trans. R. Soc. Lond. B 334, 57—84 (1991)).

The divided eye of the isopod Glyptonotus antarcticus : effects of unilateral dark adaptation and temperature elevation

1982 ◽  
Vol 215 (1201) ◽  
pp. 433-450 ◽  
Keyword(s):  
Membrane Damage ◽  
Pigment Granule ◽  
Bright Light ◽  
Interstitial Cells ◽  
The Other ◽  
Compound Eyes ◽  
Temperature Elevation ◽  
Dark Light ◽  
Pigment Granules ◽  
Screening Pigment

The literature on the structure and function of isopod compound eyes is briefly reviewed. Unlike other isopods studied, Glyptonotus antarcticus possesses physi­cally separated large dorsal compound eyes and small ventral compound eyes. G. antarcticus turns upside down when it swims, and it seems that this is when the ventrally located eyes become useful. Structurally, the two types of eye are very similar : both consist of individual ommatidia, which in an adult specimen can be 80–100 μm wide and 300 μm long. Each ommatidium contains a bipartite crystalline cone and a long rhabdom, approximately 100 μm long, which is characteristically star-shaped when sectioned transversely. Sometimes five and sometimes six retinula cells contribute to the formation of the centrally located, fused and unbanded rhabdom. Dark-light adaptational changes were difficult to demonstrate and did not occur until one eye was kept covered and shielded from light for one week, while the other one remained uncovered. In eye pairs of five animals treated in this way, it was obvious that prolonged darkness leads to an outward migration of retinula screening pigment granules, to the formation of multivesicular bodies in the retinula cells, and to an increase in size and abundance of spherical organelles in the interstitial cells. Exposure to light, on the other hand, results in an inward (towards the rhabdom) migration of retinula cell screening pigment granules, the formation of multilamellar bodies through pinocytotic processes at the rhabdom edge, and a swelling of interstitial cells. Temperature elevation alone mimics the effects of bright light with regard to pigment granule migration. It is suggested that, when pigment granules absorb radiation during exposure to light under normal environ­mental temperature conditions, they may heat up their immediate surroundings sufficiently to contribute to membrane damage.

scholarly journals Function of Insect Compound Eyes Containing Crystalline Tracts

1969 ◽  
Vol 54 (2) ◽  
pp. 250-267 ◽  
Author(s):  
Kjell B. Døving ◽  
William H. Miller
Keyword(s):  
Point Source ◽  
Theoretical Study ◽  
Visual Fields ◽  
Compound Eyes ◽  
Retinular Cell ◽  
Extended Source ◽  
Microelectrode Recordings ◽  
Extended Sources ◽  
Half Power ◽  
Retinular Cells

Image formation is studied in compound eyes of insects that contain crystalline tracts. In optical experiments the course of light is studied in fresh scalps of dark-adapted eyes using point and extended sources. In the tract region a point source gives a diffusely lighted area within which are punctate spots about 10 times brighter. Because the position of these spots does not change when the source is moved, and because their spacing agrees with estimates based on the known scalp depth, we conclude that these spots represent light radiating from the cut ends of tracts. An extended source gives a dim erect image in the tract region that may come from the pattern of illumination radiating from the cut ends of the tracts. In electrophysiological experiments intracellular microelectrode recordings of responses to illumination are made from single retinular cells of the skipper, Epargyreus clarus, an animal that lacks iris pigment. Measurements of visual fields of single retinular cells by three methods give half-power beam widths of about 2°. Though not conclusive, these experiments suggest that only the light contained in the tract is effective in stimulating the retinular cell. This agrees with the theoretical study of Allen (1968) and is inconsistent with the superposition theory of Exner (1891) as applied to certain moth and skipper eyes.

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