Intracellular recordings of light responses from spiking and nonspiking cells in the median and lateral eyes of the scorpion

Fleissner, Gerta

doi:10.1007/bf00405333

Cited by 13 publications

(15 citation statements)

References 10 publications

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“…The R‐cells of the lateral eyes are linked to a first and a second visual neuropil as well. Furthermore, the second median and the second lateral eye visual neuropils overlap each other; this means that there is a region with axon terminals from both eye types [15, 31]. A similar situation is found in the normal median and lateral eyes of Xiphosura [17, 18, 20], indicating close evolutionary relationships, at least of the visual systems.…”

Section: Discussionmentioning

confidence: 84%

“…Besides Opiliones, the basal Pycnogonida and Solifugae possess only median eyes, and Pseudoscorpiones possess only lateral eyes. However, examined in detail are only the visual systems of Pycnogonida, Xiphosura ( Limulus ), Scorpiones, and Araneae [14–24, 31]. Concerning the R-cell projections and neuropil arrangement, two different configurations have been described, with Pycnogonida, Xiphosura, and Scorpiones on the one side and Araneae on the other.…”

Section: Discussionmentioning

confidence: 99%

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The visual system of harvestmen (Opiliones, Arachnida, Chelicerata) – a re-examination

et al. 2016

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BackgroundThe visual systems in chelicerates are poorly understood, even though they show strong variation in eye and visual neuropil architecture, thus may provide valuable insights for the understanding of chelicerate phylogeny and eye evolution. Comparable morphological characters are desperately sought for reconstructions of the phylogeny of Chelicerata, especially with respect to Arachnida. So far, reliable data exist only for Pycnogonida, Xiphosura, Scorpiones, and Araneae. The few earlier studies of the organisation of the visual system in harvestmen are contradictory concerning the number, morphology, and position of the visual neuropils.ResultsWe undertook a descriptive and comparative analysis of the neuroanatomy of the visual system in several phalangid harvestmen species. Various traditional and modern methods were used that allow comparisons with previous results (cobalt fills, DiI/DiO labelling, osmium ethyl gallate procedure, and TEM). The R-cells (photoreceptor and arhabdomeric cells) in the eyes of Opiliones are linked to a first and a second visual neuropil. The first visual neuropil receives input from all R-cell axons, in the second only few R-cells terminate in the distal part. Hence, the second visual neuropil is subdivided in a part with direct R-cell input and a part without. The arcuate body is located in a subsequent position with direct contact to the second visual neuropil.ConclusionsThis re-examination comes to conclusions different from those of all previous studies. The visual system of phalangid Opiliones occupies an intermediate position between Pycnogonida, Xiphosura, and Scorpiones on the one side, and Araneae on the other side. The projection of the R-cells is similar to that in the former grouping, the general neuropil arrangement to that in the latter taxon. However, more research on the visual systems in other chelicerate orders is needed in order to draw inferences on phylogeny or eye evolution.

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Section: Discussionmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

The visual system of harvestmen (Opiliones, Arachnida, Chelicerata) – a re-examination

et al. 2016

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“…So far, the visual systems of scorpions have been studied mainly in a neurophysiological context, whereas their morphological features are undescribed on a level that would allow phylogenetic comparisons [7-9]. Holmgren [7] suggested a series of four visual neuropils (“Seemasse 1–4”), with the median eyes linked to the first and the lateral eyes to the second neuropil.…”

Section: Introductionmentioning

confidence: 99%

Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions

Lehmann

Melzer

2013

Front Zool

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BackgroundDespite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950.ResultsScorpion median eye retinula cells are linked to a first and a second visual neuropil, while some fibres additionally connect the median eyes with the arcuate body. The lateral eye retinula cells are linked to a first and a second visual neuropil as well, with the second neuropil being partly shared by projections from both eyes.ConclusionsComparing these results to previous studies on the visual systems of scorpions and other chelicerates, we found striking similarities to the innervation pattern in Limulus polyphemus for both median and lateral eyes. This supports from a visual system point of view at least a phylogenetically basal position of Scorpiones in Arachnida, or even a close relationship to Xiphosura. In addition, we propose a ground pattern for the central projections of chelicerate median eyes.

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“…Scorpion lateral eyes: Each of the lateral eye ommatidia is composed of 2-4 photoreceptor cells and one arhabdomeric cell, a light-insensitive first interneuron, postsynaptic to the photoreceptor cells (Fleissner and Siegler, 1978;Schliwa and Fleissner, 1979;1980) and similar to the median eye ommatidia, each with five visual cells and one arhabdomeric cell, Such a retinal interneuron is described also in Limulus as an eccentric cell (Fahrenbach, 1975;Calman et al, 1991) These cells process image information directly to the second optic ganglion, the medulla, by nervous action potentials, while the photoreceptors only produce graduated receptor potentials (Fleissner, 1985) along their axons to the first optic ganglion, the LA. The arrhabdomeric cells of the lateral eyes may be the base for the reduced image information via these eyes (see above).…”

Section: Neuronal Wiringmentioning

confidence: 99%

“…In a few cases of these nonvisual photoreceptors, electrophysiological data showing light-induced changes of the receptor potential or nervous discharge are available (none for Type 1 receptors; for Type 2 receptors: e.g., Geethabali and Rao, 1972;Zwicky, 1968; for Type 3 receptors: e.g., Fleissner, 1985). Most evidence for photoreceptive function is derived from immunohistochemistry or structural changes caused by light.…”

Section: Introductionmentioning

confidence: 99%

Nonvisual Photoreceptors in Arthropods with Emphasis on Their Putative Role as Receptors of Natural Zeitgeber Stimuli

Fleissner¹

2003

Chronobiology International

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Intracellular recordings of light responses from spiking and nonspiking cells in the median and lateral eyes of the scorpion

Cited by 13 publications

References 10 publications

The visual system of harvestmen (Opiliones, Arachnida, Chelicerata) – a re-examination

The visual system of harvestmen (Opiliones, Arachnida, Chelicerata) – a re-examination

Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions

Nonvisual Photoreceptors in Arthropods with Emphasis on Their Putative Role as Receptors of Natural Zeitgeber Stimuli

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