scholarly journals Two chiral types of randomly rotated ommatidia are distributed across the retina of the flathead oak borer Coraebus undatus (Coleoptera: Buprestidae)

2020 ◽  
Vol 223 (14) ◽  
pp. jeb225920 ◽  
Author(s):  
Andrej Meglič ◽  
Marko Ilić ◽  
Carmen Quero ◽  
Kentaro Arikawa ◽  
Gregor Belušič
Keyword(s):  
Color Vision ◽  
Photoreceptor Cell ◽  
The Body ◽  
Polarization Sensitivity ◽  
Compound Eyes ◽  
Polarization Vision ◽  
Intracellular Recordings ◽  
Cell Responses ◽  
Ommatidial Rotation

ABSTRACTJewel 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.

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.

Electrical interactions between the giant axons of a polychaete worm (Sabella penicillus L.)

1980 ◽  
Vol 84 (1) ◽  
pp. 119-136
Author(s):  
D. Mellon ◽  
J. E. Treherne ◽  
N. J. Lane ◽  
J. B. Harrison ◽  
C. K. Langley
Keyword(s):  
Safety Factor ◽  
Nerve Cord ◽  
Action Potentials ◽  
Divalent Cations ◽  
Muscular Contraction ◽  
The Body ◽  
The Other ◽  
Intracellular Recordings ◽  
Giant Axons ◽  
Other Hand

Intracellular recordings demonstrated a transfer of impulses between the paired giant axons of Sabella, apparently along narrow axonal processes contained within the paired commissures which link the nerve cords in each segment of the body. This transfer appears not to be achieved by chemical transmission, as has been previously supposed. This is indicated by the spread of depolarizing and hyperpolarizing voltage changes between the giant axons, the lack of effects of changes in the concentrations of external divalent cations on impulse transmission and by the effects of hyperpolarization in reducing the amplitude of the depolarizing potential which precedes the action potentials in the follower axon. The ten-to-one attenuation of electronic potentials between the giant axons argues against the possibility of an exclusively passive spread of potential along the axonal processes which link the axons. Observation of impulse traffic within the nerve cord commissures indicates, on the other hand, that transmission is achieved by conduction of action potentials along the axonal processes which link the giant axons. At least four pairs of intact commissures are necessary for inter-axonal transmission, the overall density of current injected at multiple sites on the follower axon being, it is presumed, sufficient to overcome the reduction in safety factor imposed by the geometry of the system in the region where axonal processes join the giant axons. The segmental transmission between the giant axons ensures effective synchronization of impulse traffic initiated in any region of the body and, thus, co-ordination of muscular contraction, during rapid withdrawal responses of the worm.

Functional similarities between polarization vision and color vision

1977 ◽  
Vol 17 (9) ◽  
pp. 1019-1028 ◽  
Author(s):  
Gary D. Bernard ◽  
Rüdiger Wehner
Keyword(s):  
Color Vision ◽  
Polarization Vision

Body-size scaling of metabolic rate in the trilobite Eldredgeops rana

Paleobiology ◽  
2013 ◽  
Vol 39 (1) ◽  
pp. 109-122 ◽  
Author(s):  
Douglas S. Glazier ◽  
Matthew G. Powell ◽  
Travis J. Deptola
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Cell Size ◽  
The Body ◽  
Cell Multiplication ◽  
Compound Eyes ◽  
Metabolic Scaling ◽  
Size Scaling ◽  
Size Model ◽  
Facet Size

We infer the body-size scaling slope of metabolic rate in a trilobite by applying a cell-size model that has been proposed to explain metabolic scaling in living organisms. This application is especially tractable in fossil arthropods with well-preserved compound eyes because the number and size of eye facets appear to be useful proxies for the relative number and size of cells in the body. As a case study, we examined the ontogenetic scaling of facet size and number in a ∼390-Myr-old local assemblage of the trilobite Eldredgeops rana, which has well-preserved compound eyes and a wide body-size range. Growth in total eye lens area resulted from increases in both facet area and number in relatively small (presumably young) specimens, but only from increases in facet area in large (presumably more mature) specimens. These results suggest that early growth in E. rana involved both cell multiplication and enlargement, whereas later growth involved only cell enlargement. If the cell-size model is correct, then metabolic rate scaled allometrically in E. rana, and the scaling slope of log metabolic rate versus log body mass decreased from ∼0.85 to 0.63 as these animals grew. This inferred age-specific change in metabolic scaling is consistent with similar changes frequently observed in living animals. Additional preliminary analyses of literature data on other trilobites also suggest that the metabolic scaling slope was <1 in benthic species, but ∼1 in pelagic species, as has also been observed in living invertebrates. The eye-facet size (EFS) method featured here opens up new possibilities for examining the bioenergetic allometry of extinct arthropods.

Excitation of motoneurons by the Mauthner axon in goldfish: complexities in a "simple" reticulospinal pathway

1992 ◽  
Vol 67 (6) ◽  
pp. 1574-1586 ◽  
Author(s):  
J. R. Fetcho
Keyword(s):  
Escape Behavior ◽  
Mean Amplitude ◽  
Short Latency ◽  
The Body ◽  
Intracellular Recordings ◽  
M Cell ◽  
Mauthner Cell ◽  
Monosynaptic Connection ◽  
Direct Excitation ◽  
Descending Interneurons

1. The Mauthner cell in fish and amphibians initiates an escape behavior that has served as a model system for studies of the reticulospinal control of movement. This behavior consists of a very rapid bend of the body and tail that is thought to arise from the monosynaptic excitation of large primary motoneurons by the Mauthner cell. Recent work suggests that the excitation of primary motoneurons might be more complex than a solely monosynaptic connection. To examine this possibility, I used intracellular recording and staining to study the excitation of primary motoneurons by the M cell. 2. Simultaneous intracellular recordings from the M axon and ipsilateral primary motoneurons show that firing the M cell leads to complex postsynaptic potentials (PSPs) in the motoneurons. These PSPs usually have three components: an early, small, slow depolarization (component 1), a later, large, fast depolarization (component 2), and an even later, large, long-lasting depolarization (component 3). The first component has a latency of 0.52 +/- 0.15 (SD) ms, (n = 27) and most probably is a monosynaptic input from the M cell. This study focused on the two subsequent, less-understood parts of the PSP. Motoneurons typically fire off the second part of the PSP. This is usually (27 of 33 cells) the largest component, and it has a mean amplitude of 6.24 +/- 3.33 (SD) mV (n = 33) and a half-decay time of 0.44 +/- 0.18 (SD) ms (n = 27). The mean amplitude of the third component is 3.20 +/- 1.7 (SD) mV (n = 35), and its half-decay is 6.73 +/- 2.66 (SD) ms (n = 35). The latency of the second component averages 0.66 +/- 0.21 (SD) ms (n = 32), indicating that there are few synapses in the pathway mediating it. 3. One candidate pathway for the second component of the PSP involves a class of descending interneurons (DIs) that are monosynaptically, chemically excited by the M cell and appear in light microscopy to contact motoneurons. Simultaneous intracellular recordings from the M axon, a DI, and a primary motoneuron show that the interneurons are electrotonically coupled to motoneurons and produce the fast, second component of the PSP. Direct excitation of an interneuron leads to a very short-latency (less than 0.2 ms), fast PSP in a motoneuron similar to the second component of the PSP produced by the M axon. The short latency and fatigue resistance of this connection indicate it is electrotonic, and this is supported by evidence for DC coupling between the two cells.(ABSTRACT TRUNCATED AT 400 WORDS)

New species of bristletails of the family Machilidae (Archaeognatha) from Kazakhstan

2021 ◽  
pp. 435-445
Author(s):  
Vladimir Kaplin ◽  
Georgiy Shakula
Keyword(s):  
New Species ◽  
Body Shape ◽  
Compound Eye ◽  
Ventral Surface ◽  
Maxillary Palp ◽  
The Body ◽  
Compound Eyes ◽  
Labial Palp ◽  
The Family ◽  
One New Species

The fauna of bristletails of the family Machilidae in Kazakhstan currently includes one species of the genus Silvestrichiloides Mendes, 1990 and 13 species of the genus Allopsontus Silvestri, 1911. The present study describes one new species of the genus Silvestrichiloides (S. berkarensis Kaplin, sp. nov. from South Kazakhstan) and two new species of the genus Allopsontus (A. (Kaplinilis) nigrostriatus Kaplin, sp. nov. and A. (Machilanus) perfectus Kaplin, sp. nov. from Southeastern Kazakhstan). Silvestrichiloides berkarensis sp. nov. differs from the other species of this genus in the structure of antennal flagellum, apical palpomere of labial palp and ovipositor. Among species of the subgenus Kaplinilis Mendes, 1990, A. nigrostriatus sp. nov. belongs to a group of species characterized by numerous short chaetae on the ventral surface of the 5–7th palpomeres of the male maxillary palp and by the absence on the labial palp. This group includes two species: A. volgensis Kaplin, 1999 from Samara Region and A. smelyanskii Kaplin, 1999 from Orenbourg Region (both Russia). The new species differs from A. volgensis and A. smelyanskii in the length of the body and antenna, color of scales on the upper surface of the body, shape of the compound eye and paired ocellus, structure of the flagellum and apical palpomere of the male labial palp. The subgenus Machilanus Silvestri, 1934 is represented only by A. bitschi Wygodzinsky, 1962 from Afghanistan and A. perfectus sp. nov., which are characterized by numerous short chaetae on the ventral surface of the 2nd–7th palpomeres of the male maxillary palp. Allopsontus perfectus sp. nov. differs from A. bitschi in the shape of compound eyes, paired ocellus, structure of male labial palp and genitalia.

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.

Does a nano-scale nipple array (moth-eye structure) suppress the settlement of ascidian larvae?

2019 ◽  
Vol 99 (06) ◽  
pp. 1393-1397 ◽  
Author(s):  
Euichi Hirose ◽  
Noburu Sensui
Keyword(s):  
Body Surface ◽  
Flat Surface ◽  
Larval Settlement ◽  
The Body ◽  
Compound Eyes ◽  
Substrate Selection ◽  
Reflection Property ◽  
Nano Scale ◽  
Sessile Organisms

AbstractIn some metazoans, the body surface is entirely or partly covered with an array of nipples about 100 nm or less in height. This structure, a nipple array, is sometimes called the moth-eye structure because it serves as an anti-reflection property on the compound eyes of a night moth. The nipple array is supposed to be a multifunctional structure since this structure occurs in various species across different taxa. Here, we hypothesize that the nipple array may prevent the settlement of epibionts that are often a nuisance and potentially cause serious problems for the host. Using a synthetic film that imitates the nipple array, we tested the substrate selection within ascidian larval settlement. The results indicate that the nipple array has anti-fouling properties, since more larvae settled on the flat surface than the nipple array (P &lt; 0.01, paired t-test). The present results demonstrated that the nipple array potentially serves an anti-fouling function on the body surface, which should be important especially for sessile organisms.

scholarly journals Sacculocollic Reflex Arcs in Cats

1997 ◽  
Vol 77 (6) ◽  
pp. 3003-3012 ◽  
Author(s):  
Y. Uchino ◽  
H. Sato ◽  
M. Sasaki ◽  
M. Imagawa ◽  
H. Ikegami ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Nerve Stimulation ◽  
Vestibular Nerve ◽  
The Body ◽  
Lateral Part ◽  
Intracellular Recordings ◽  
Decerebrate Cat ◽  
Postsynaptic Potentials ◽  
Saccular Nerve ◽  
Sacculocollic Reflex

Uchino, Y., H. Sato, M. Sasaki, M. Imagawa, H. Ikegami, N. Isu, and W. Graf. Sacculocollic reflex arcs in cats. J. Neurophysiol. 77: 3003–3012, 1997. Neuronal connections and pathways underlying sacculocollic reflexes were studied by intracellular recordings from neck extensor and flexor motoneurons in decerebrate cat. Bipolar electrodes were placed within the left saccular nerve, whereas other branches of the vestibular nerve were removed in the inner ear. To prevent spread of stimulus current to other branches of the vestibular nerve, the saccular nerve and the electrodes were covered with warm semisolid paraffin-Vaseline mixture. Saccular nerve stimulation evoked disynaptic (1.8–3.0 ms) excitatory postsynaptic potentials (EPSPs) in ipsilateral neck extensor motoneurons and di- or trisynaptic (1.8–4.0 ms) EPSPs in contralateral neck extensor motoneurons, and di- and trisynaptic (1.7–3.6 ms) inhibitory postsynaptic potentials (IPSPs) in ipsilateral neck flexor motoneurons and trisynaptic (2.7–4.0 ms) IPSPs in contralateral neck flexor motoneurons. Ipsilateral inputs were about twice as strong as contralateral ones to both extensor and flexor motoneurons. To determine the pathways mediating this connectivity, the lateral part of the spinal cord containing the ipsilateral lateral vestibulospinal tract (i-LVST) or the central part of the spinal cord containing the medial vestibulospinal tracts (MVSTs) and possibly reticulospinal fibers (RSTs) were transected at the caudal end of the C1 segment. Subsequent renewed intracellular recordings following sacculus nerve stimulation indicated that the pathway from the saccular nerve to the ipsilateral neck extensor motoneurons projects though the i-LVST, whereas the pathways to the contralateral neck extensors and to the bilateral neck flexor motoneurons descend in the MVSTs/RSTs. Our data show that sacculo-neck reflex connections display a qualitatively bilaterally symmetrical innervation pattern with excitatory connections to both neck extensor motoneuron pools, and inhibitory connections to both neck flexor motoneuron pools. This bilateral organization contrasts with the unilateral innervation scheme of the utriculus system. These results suggest a different symmetry plane along which sacculus postural reflexes are organized, thus supplementing the reference planes of the utriculus system and allowing the gravistatic system to represent all three translational spatial degrees of freedom. We furthermore suggest that the sacculocollic reflex plays an important role in maintaining the relative position of the head and the body against the vertical linear acceleration of gravity.

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