The Experts below are selected from a list of 3210 Experts worldwide ranked by ideXlab platform
Kentaro Arikawa - One of the best experts on this subject based on the ideXlab platform.
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two chiral types of randomly rotated Ommatidia are distributed across the retina of the flathead oak borer coraebus undatus coleoptera buprestidae
The Journal of Experimental Biology, 2020Co-Authors: Andrej Meglic, Kentaro Arikawa, Marko Ilic, Carmen Quero, Gregor BelusicAbstract:ABSTRACT Jewel beetles are colorful insects, which use vision to recognize their conspecifics and can be lured with colored traps. We investigated the retina and coloration of one member of this family, the flathead oak borer Coraebus undatus using microscopy, spectrometry, polarimetry, electroretinography and intracellular recordings of photoreceptor cell responses. The compound eyes are built of a highly unusual mosaic of mirror-symmetric or chiral Ommatidia that are randomly rotated along the body axes. Each ommatidium has eight photoreceptors, two of them having rhabdomeres in tiers. The eyes contain six spectral classes of photoreceptors, peaking in the UV, blue, green and red. Most photoreceptors have moderate polarization sensitivity with randomly distributed angular maxima. The beetles have the necessary retinal substrate for complex color vision, required to recognize conspecifics and suitable for a targeted design of color traps. However, the jewel beetle array of freely rotated Ommatidia is very different from the ordered mosaic in insects that have object-directed polarization vision. We propose that Ommatidial rotation enables the cancelling out of polarization signals, thus allowing stable color vision, similar to the rhabdomeric twist in the eyes of flies and honeybees.
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chromatic information processing in the first optic ganglion of the butterfly papilio xuthus
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2020Co-Authors: Peiju Chen, Gregor Belusic, Kentaro ArikawaAbstract:The butterfly Papilio xuthus has acute tetrachromatic color vision. Its eyes are furnished with eight spectral classes of photoreceptors, situated in three types of Ommatidia, randomly distributed in the retinal mosaic. Here, we investigated early chromatic information processing by recording spectral, angular, and polarization sensitivities of photoreceptors and lamina monopolar cells (LMCs). We identified three spectral classes of LMCs whose spectral sensitivities corresponded to weighted linear sums of the spectral sensitivities of the photoreceptors present in the three Ommatidial types. In ~ 25% of the photoreceptor axons, the spectral sensitivities differed from those recorded at the photoreceptor cell bodies. These axons showed spectral opponency, most likely mediated by chloride ion currents through histaminergic interphotoreceptor synapses. The opponency was most prominent in the processes of the long visual fibers in the medulla. We recalculated the wavelength discrimination function using the noise-limited opponency model to reflect the new spectral sensitivity data and found that it matched well with the behaviorally determined function. Our results reveal opponency at the first stage of Papilio’s visual system, indicating that spectral information is preprocessed with signals from photoreceptors within each ommatidium in the lamina, before being conveyed downstream by the long visual fibers and the LMCs.
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spectral organization of Ommatidia in flower visiting insects
Photochemistry and Photobiology, 2007Co-Authors: Motohiro Wakakuwa, Doekele G. Stavenga, Kentaro ArikawaAbstract:This article reviews recent advances of studies on the spectral organization of the compound eye in lepidopteran and hymenopteran insects. The compound eyes consist of Ommatidia, which contain a set of photoreceptor cells. The common feature is that the Ommatidia can be divided into three types, according to the combination of spectral classes of photoreceptors. Honeybees and nymphalid butterflies provide the simplest case with three photoreceptor classes having peak sensitivities in the ultraviolet (UV), blue (B), or green (G) wavelength region. These receptors populate the Ommatidia in fixed combinations. In type I Ommatidia, the main eight photoreceptors consist of one UV, one B, and six G receptors. Type II has two UV and six G receptors, and type III has two B and six G receptors. The organization is basically retained in all insect species studied so far, although some butterflies have more than six classes of spectral receptors, including those sensitive in the violet and red wavelength regions. To acquire these additional receptors, two distinct strategies are applied: the multiple opsin strategy, taken by the Japanese yellow swallowtail butterfly Papilio xuthus, and the filter strategy, used by the small white butterfly Pieris rapae.
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Ommatidial type specific interphotoreceptor connections in the lamina of the swallowtail butterfly papilio xuthus
The Journal of Comparative Neurology, 2006Co-Authors: Shinya Takemura, Kentaro ArikawaAbstract:The eye of the butterfly Papilio xuthus contains a random array of three types of Ommatidia (types I-III), each bearing nine photoreceptors, R1-R9. Of the six spectral classes of photoreceptors identified, types I, II, and III Ommatidia contain four, three, and two classes, respectively: the Ommatidia are thus spectrally heterogeneous. The photoreceptors send their axons to the lamina where, together with some large monopolar cells (LMCs), the nine from a single ommatidium contribute to a module called a lamina cartridge. We recently reported that among different photoreceptor axon terminals visualized by confocal microscopy, the number and length of axon collaterals differ for different spectral receptors, suggesting that lamina circuits are specific for each Ommatidial type. Here we studied the distribution of synapse-like structures in the cartridges, first characterizing a photoreceptor by measuring its spectral sensitivity and then injecting Lucifer yellow (LY). We subsequently histologically identified the type of ommatidium to which the injected photoreceptor belonged, cut serial ultrathin sections of the entire lamina, labeled these with anti-LY immunocytochemistry, and then localized synapse-like structures. We found numerous interphotoreceptor contacts both within and between cartridges, the combination of which was again specific for the Ommatidial type. R3 and R4, which are green-sensitive photoreceptors in all Ommatidia, have thick axons lacking collaterals. We found that these cells exclusively make contacts with LMCs and not with photoreceptors. We therefore presume that R3 and R4 construct a system for motion vision, whereas other randomly distributed spectral types provide inputs for color vision.
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Ommatidial type specific interphotoreceptor connections in the lamina of the swallowtail butterfly papilio xuthus
The Journal of Comparative Neurology, 2006Co-Authors: Shinya Takemura, Kentaro ArikawaAbstract:The eye of the butterfly Papilio xuthus contains a random array of three types of Ommatidia (types I–III), each bearing nine photoreceptors, R1–R9. Of the six spectral classes of photoreceptors identified, types I, II, and III Ommatidia contain four, three, and two classes, respectively: the Ommatidia are thus spectrally heterogeneous. The photoreceptors send their axons to the lamina where, together with some large monopolar cells (LMCs), the nine from a single ommatidium contribute to a module called a lamina cartridge. We recently reported that among different photoreceptor axon terminals visualized by confocal microscopy, the number and length of axon collaterals differ for different spectral receptors, suggesting that lamina circuits are specific for each Ommatidial type. Here we studied the distribution of synapse-like structures in the cartridges, first characterizing a photoreceptor by measuring its spectral sensitivity and then injecting Lucifer yellow (LY). We subsequently histologically identified the type of ommatidium to which the injected photoreceptor belonged, cut serial ultrathin sections of the entire lamina, labeled these with anti-LY immunocytochemistry, and then localized synapse-like structures. We found numerous interphotoreceptor contacts both within and between cartridges, the combination of which was again specific for the Ommatidial type. R3 and R4, which are green-sensitive photoreceptors in all Ommatidia, have thick axons lacking collaterals. We found that these cells exclusively make contacts with LMCs and not with photoreceptors. We therefore presume that R3 and R4 construct a system for motion vision, whereas other randomly distributed spectral types provide inputs for color vision. J. Comp. Neurol. 494:663–672, 2006. © 2005 Wiley-Liss, Inc.
Doekele G. Stavenga - One of the best experts on this subject based on the ideXlab platform.
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spectral organization of Ommatidia in flower visiting insects
Photochemistry and Photobiology, 2007Co-Authors: Motohiro Wakakuwa, Doekele G. Stavenga, Kentaro ArikawaAbstract:This article reviews recent advances of studies on the spectral organization of the compound eye in lepidopteran and hymenopteran insects. The compound eyes consist of Ommatidia, which contain a set of photoreceptor cells. The common feature is that the Ommatidia can be divided into three types, according to the combination of spectral classes of photoreceptors. Honeybees and nymphalid butterflies provide the simplest case with three photoreceptor classes having peak sensitivities in the ultraviolet (UV), blue (B), or green (G) wavelength region. These receptors populate the Ommatidia in fixed combinations. In type I Ommatidia, the main eight photoreceptors consist of one UV, one B, and six G receptors. Type II has two UV and six G receptors, and type III has two B and six G receptors. The organization is basically retained in all insect species studied so far, although some butterflies have more than six classes of spectral receptors, including those sensitive in the violet and red wavelength regions. To acquire these additional receptors, two distinct strategies are applied: the multiple opsin strategy, taken by the Japanese yellow swallowtail butterfly Papilio xuthus, and the filter strategy, used by the small white butterfly Pieris rapae.
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a unique visual pigment expressed in green red and deep red receptors in the eye of the small white butterfly pieris rapae crucivora
The Journal of Experimental Biology, 2004Co-Authors: Motohiro Wakakuwa, Doekele G. Stavenga, Masumi KurasawaAbstract:SUMMARY The full primary structure of a long-wavelength absorbing visual pigment of the small white butterfly, Pieris rapae crucivora , was determined by molecular cloning. In situ hybridization of the opsin mRNA of the novel visual pigment (PrL) demonstrated that it is expressed in the two distal photoreceptor cells (R3 and R4) as well as in the proximal photoreceptors (R5–8) in all three types of Ommatidia of the Pieris eye. The main, long-wavelength band of the spectral sensitivities of the R3 and R4 photoreceptors is well described by the absorption spectrum of a visual pigment with absorption maximum at 563 nm; i.e. PrL is a visual pigment R563. The spectral sensitivities of R5–8 photoreceptors in Ommatidial type I and III peak at 620 nm and those in type II Ommatidia peak at 640 nm. The large shifts of the spectral sensitivities of the R5–8 photoreceptors with respect to the absorption spectrum of their visual pigment can be explained with the spectral filtering by pale-red (PR) and deep-red (DR) screening pigments that are concentrated in clusters of granules near the rhabdom boundary. The peak absorbance of the two spectral filters appears to be approximately 1 (PR) and 2 (DR).
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coexpression of two visual pigments in a photoreceptor causes an abnormally broad spectral sensitivity in the eye of the butterfly papilio xuthus
The Journal of Neuroscience, 2003Co-Authors: Kentaro Arikawa, Michiyo Kinoshita, Shin Mizuno, Doekele G. StavengaAbstract:The compound eye of the butterfly Papilio xuthus consists of three different types of Ommatidia, each containing nine photoreceptor cells (R1–R9). We have found previously that the R5–R8 photoreceptors of type II Ommatidia coexpress two different mRNAs, encoding opsins of green- and orange-red-absorbing visual pigments (Kitamoto et al., 1998). Do these cells contain two functionally distinct visual pigments? First, we identified the sensitivity spectrum of these photoreceptors by using combined intracellular recording and dye injection. We thus found that the R5–R8 of type II Ommatidia have a characteristic sensitivity spectrum extending over an excessively broad spectral range, from the violet to the red region; the photoreceptors are therefore termed broadband photoreceptors. The spectral shape was interpreted with a computational model for type II Ommatidia, containing a UV visual pigment in cells R1 and R2, two green visual pigments in cells R3 and R4, a far-UV-absorbing screening pigment (3-hydroxyretinol) in the distal part of the ommatidium, and a red-screening pigment that surrounds the rhabdom. The modeling suggests that both visual pigments in the R5–R8 photoreceptors participate in phototransduction. This work provides the first compelling evidence that multiple visual pigments participate in phototransduction in single invertebrate photoreceptors.
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reflections on colourful Ommatidia of butterfly eyes
The Journal of Experimental Biology, 2002Co-Authors: Doekele G. StavengaAbstract:The eye shine of butterflies from a large number of Ommatidia was observed with a modified epi-illumination apparatus equipped with an objective lens of large numerical aperture. A few representative cases are presented: the satyrine Bicyclus anynana, the heliconian Heliconius melpomene, the small white Pieris rapae and the small copper Lycaena phlaeas. The colour of the eye shine is determined mainly by the reflectance spectrum of the tapetal mirror and the transmittance spectrum of the photoreceptor screening pigments, if present near the light-guiding rhabdom. Reflectance spectra measured from individual Ommatidia show that tapetum and screening pigments are co-expressed in fixed combinations, thus determining different Ommatidial classes. The classes are distributed in an irregular pattern that can be rapidly assessed with the novel epi-illumination apparatus. Many butterfly species appear to have red-reflecting Ommatidia, which is interpreted to indicate the presence of red-sensitive photoreceptors.
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Ommatidial heterogeneity in the compound eye of the male small white butterfly pieris rapae crucivora
Cell and Tissue Research, 2002Co-Authors: Kurt A J Vanhoutte, Doekele G. Stavenga, Kentaro ArikawaAbstract:The Ommatidia in the ventral two-thirds of the compound eye of male Pieris rapae crucivora are not uniform. Each ommatidium contains nine photoreceptor cells. Four cells (R1–4) form the distal two-thirds of the rhabdom, four cells (R5–8) approximately occupy the proximal one-third of the rhabdom, and the ninth cell (R9) takes up a minor basal part of the rhabdom. The R5–8 photoreceptor cells contain clusters of reddish pigment adjacent to the rhabdom. From the position of the pigment clusters, three types of Ommatidia can be identified: the trapezoidal (type I), square (type II), and rectangular type (type III). Microspectrophotometry with an epi-illumination microscope has revealed that the reflectance spectra of type I and type III Ommatidia peak at 635 nm and those of type II Ommatidia peak at 675 nm. The bandwith of the reflectance spectra is 40–50 nm. Type II Ommatidia strongly fluoresce under ultra-violet and violet epi-illumination. The three types of Ommatidia are randomly distributed. The Ommatidial heterogeneity is presumably crucial for color discrimination.
Gregor Belusic - One of the best experts on this subject based on the ideXlab platform.
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two chiral types of randomly rotated Ommatidia are distributed across the retina of the flathead oak borer coraebus undatus coleoptera buprestidae
The Journal of Experimental Biology, 2020Co-Authors: Andrej Meglic, Kentaro Arikawa, Marko Ilic, Carmen Quero, Gregor BelusicAbstract:ABSTRACT Jewel beetles are colorful insects, which use vision to recognize their conspecifics and can be lured with colored traps. We investigated the retina and coloration of one member of this family, the flathead oak borer Coraebus undatus using microscopy, spectrometry, polarimetry, electroretinography and intracellular recordings of photoreceptor cell responses. The compound eyes are built of a highly unusual mosaic of mirror-symmetric or chiral Ommatidia that are randomly rotated along the body axes. Each ommatidium has eight photoreceptors, two of them having rhabdomeres in tiers. The eyes contain six spectral classes of photoreceptors, peaking in the UV, blue, green and red. Most photoreceptors have moderate polarization sensitivity with randomly distributed angular maxima. The beetles have the necessary retinal substrate for complex color vision, required to recognize conspecifics and suitable for a targeted design of color traps. However, the jewel beetle array of freely rotated Ommatidia is very different from the ordered mosaic in insects that have object-directed polarization vision. We propose that Ommatidial rotation enables the cancelling out of polarization signals, thus allowing stable color vision, similar to the rhabdomeric twist in the eyes of flies and honeybees.
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chromatic information processing in the first optic ganglion of the butterfly papilio xuthus
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2020Co-Authors: Peiju Chen, Gregor Belusic, Kentaro ArikawaAbstract:The butterfly Papilio xuthus has acute tetrachromatic color vision. Its eyes are furnished with eight spectral classes of photoreceptors, situated in three types of Ommatidia, randomly distributed in the retinal mosaic. Here, we investigated early chromatic information processing by recording spectral, angular, and polarization sensitivities of photoreceptors and lamina monopolar cells (LMCs). We identified three spectral classes of LMCs whose spectral sensitivities corresponded to weighted linear sums of the spectral sensitivities of the photoreceptors present in the three Ommatidial types. In ~ 25% of the photoreceptor axons, the spectral sensitivities differed from those recorded at the photoreceptor cell bodies. These axons showed spectral opponency, most likely mediated by chloride ion currents through histaminergic interphotoreceptor synapses. The opponency was most prominent in the processes of the long visual fibers in the medulla. We recalculated the wavelength discrimination function using the noise-limited opponency model to reflect the new spectral sensitivity data and found that it matched well with the behaviorally determined function. Our results reveal opponency at the first stage of Papilio’s visual system, indicating that spectral information is preprocessed with signals from photoreceptors within each ommatidium in the lamina, before being conveyed downstream by the long visual fibers and the LMCs.
Motohiro Wakakuwa - One of the best experts on this subject based on the ideXlab platform.
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spectral organization of Ommatidia in flower visiting insects
Photochemistry and Photobiology, 2007Co-Authors: Motohiro Wakakuwa, Doekele G. Stavenga, Kentaro ArikawaAbstract:This article reviews recent advances of studies on the spectral organization of the compound eye in lepidopteran and hymenopteran insects. The compound eyes consist of Ommatidia, which contain a set of photoreceptor cells. The common feature is that the Ommatidia can be divided into three types, according to the combination of spectral classes of photoreceptors. Honeybees and nymphalid butterflies provide the simplest case with three photoreceptor classes having peak sensitivities in the ultraviolet (UV), blue (B), or green (G) wavelength region. These receptors populate the Ommatidia in fixed combinations. In type I Ommatidia, the main eight photoreceptors consist of one UV, one B, and six G receptors. Type II has two UV and six G receptors, and type III has two B and six G receptors. The organization is basically retained in all insect species studied so far, although some butterflies have more than six classes of spectral receptors, including those sensitive in the violet and red wavelength regions. To acquire these additional receptors, two distinct strategies are applied: the multiple opsin strategy, taken by the Japanese yellow swallowtail butterfly Papilio xuthus, and the filter strategy, used by the small white butterfly Pieris rapae.
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Spectral heterogeneity of honeybee Ommatidia
Naturwissenschaften, 2005Co-Authors: Motohiro Wakakuwa, Masumi Kurasawa, Martin Giurfa, Kentaro ArikawaAbstract:The honeybee compound eye is equipped with ultraviolet, blue, and green receptors, which form the physiological basis of a trichromatic color vision system. We studied the distribution of the spectral receptors by localizing the three mRNAs encoding the opsins of the ultraviolet-, blue- and green-absorbing visual pigments. The expression patterns of the three opsin mRNAs demonstrated that three distinct types Ommatidia exist, refuting the common assumption that the Ommatidia composing the bee compound eye contain identical sets of spectral receptors. We found that type I Ommatidia contain one ultraviolet and one blue receptor, type II Ommatidia contain two ultraviolet receptors, and type III Ommatidia have two blue receptors. All the three Ommatidial types contain six green receptors. The Ommatidia appear to be distributed rather randomly over the retina. The ratio of type I, II, and III Ommatidia was about 44:46:10. Type III Ommatidia appeared to be slightly more frequent (18%) in the anterior part of the ventral region of the eye. Retinal heterogeneity and Ommatidial randomness, first clearly demonstrated in butterflies, seems to be a common design principle of the eyes of insects.
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a unique visual pigment expressed in green red and deep red receptors in the eye of the small white butterfly pieris rapae crucivora
The Journal of Experimental Biology, 2004Co-Authors: Motohiro Wakakuwa, Doekele G. Stavenga, Masumi KurasawaAbstract:SUMMARY The full primary structure of a long-wavelength absorbing visual pigment of the small white butterfly, Pieris rapae crucivora , was determined by molecular cloning. In situ hybridization of the opsin mRNA of the novel visual pigment (PrL) demonstrated that it is expressed in the two distal photoreceptor cells (R3 and R4) as well as in the proximal photoreceptors (R5–8) in all three types of Ommatidia of the Pieris eye. The main, long-wavelength band of the spectral sensitivities of the R3 and R4 photoreceptors is well described by the absorption spectrum of a visual pigment with absorption maximum at 563 nm; i.e. PrL is a visual pigment R563. The spectral sensitivities of R5–8 photoreceptors in Ommatidial type I and III peak at 620 nm and those in type II Ommatidia peak at 640 nm. The large shifts of the spectral sensitivities of the R5–8 photoreceptors with respect to the absorption spectrum of their visual pigment can be explained with the spectral filtering by pale-red (PR) and deep-red (DR) screening pigments that are concentrated in clusters of granules near the rhabdom boundary. The peak absorbance of the two spectral filters appears to be approximately 1 (PR) and 2 (DR).
Masumi Kurasawa - One of the best experts on this subject based on the ideXlab platform.
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Spectral heterogeneity of honeybee Ommatidia
Naturwissenschaften, 2005Co-Authors: Motohiro Wakakuwa, Masumi Kurasawa, Martin Giurfa, Kentaro ArikawaAbstract:The honeybee compound eye is equipped with ultraviolet, blue, and green receptors, which form the physiological basis of a trichromatic color vision system. We studied the distribution of the spectral receptors by localizing the three mRNAs encoding the opsins of the ultraviolet-, blue- and green-absorbing visual pigments. The expression patterns of the three opsin mRNAs demonstrated that three distinct types Ommatidia exist, refuting the common assumption that the Ommatidia composing the bee compound eye contain identical sets of spectral receptors. We found that type I Ommatidia contain one ultraviolet and one blue receptor, type II Ommatidia contain two ultraviolet receptors, and type III Ommatidia have two blue receptors. All the three Ommatidial types contain six green receptors. The Ommatidia appear to be distributed rather randomly over the retina. The ratio of type I, II, and III Ommatidia was about 44:46:10. Type III Ommatidia appeared to be slightly more frequent (18%) in the anterior part of the ventral region of the eye. Retinal heterogeneity and Ommatidial randomness, first clearly demonstrated in butterflies, seems to be a common design principle of the eyes of insects.
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a unique visual pigment expressed in green red and deep red receptors in the eye of the small white butterfly pieris rapae crucivora
The Journal of Experimental Biology, 2004Co-Authors: Motohiro Wakakuwa, Doekele G. Stavenga, Masumi KurasawaAbstract:SUMMARY The full primary structure of a long-wavelength absorbing visual pigment of the small white butterfly, Pieris rapae crucivora , was determined by molecular cloning. In situ hybridization of the opsin mRNA of the novel visual pigment (PrL) demonstrated that it is expressed in the two distal photoreceptor cells (R3 and R4) as well as in the proximal photoreceptors (R5–8) in all three types of Ommatidia of the Pieris eye. The main, long-wavelength band of the spectral sensitivities of the R3 and R4 photoreceptors is well described by the absorption spectrum of a visual pigment with absorption maximum at 563 nm; i.e. PrL is a visual pigment R563. The spectral sensitivities of R5–8 photoreceptors in Ommatidial type I and III peak at 620 nm and those in type II Ommatidia peak at 640 nm. The large shifts of the spectral sensitivities of the R5–8 photoreceptors with respect to the absorption spectrum of their visual pigment can be explained with the spectral filtering by pale-red (PR) and deep-red (DR) screening pigments that are concentrated in clusters of granules near the rhabdom boundary. The peak absorbance of the two spectral filters appears to be approximately 1 (PR) and 2 (DR).
