Summary
Based on reconstructions from serial thin sections, arhabdomeric cells within the retina of the median eyes of the scorpion,Androctonus australis, are identified. Each retinula unit (formed by mainly five retinula cells with a fused rhabdom) is associated with one arhabdomeric cell. Extending distally from its soma which is located close to the postretina, the arhabdomeric cell bears an up to 80 μm long dendrite that ends at the base of the fused rhabdom. The most noteworthy morphological feature of the dendrite is the presence, at the distal dendrite tip, of numerous finger-like or bulbous evaginations that extend into every one of the five visual cells forming a retinula unit. These and other characteristics strongly suggest that the arhabdomeric cell represents an intrinsically photoinsensitive second neuron involved in visual information processing.
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This study was supportet by a grant from the Deutsche Forschungs-gemeinschaft (F1 77/8).
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Schliwa, M., Fleissner, G. Arhabdomeric cells of the median eye retina of scorpions. J. Comp. Physiol. 130, 265–270 (1979). https://doi.org/10.1007/BF00614613
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DOI: https://doi.org/10.1007/BF00614613