Randy C. Morgan

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The larvae of the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae), are highly efficient visually guided predators. Their visual system consists of a cluster of six stemmata and one eye patch on each side of the head capsule. Histological investigations show that the organization of individual stemmata differs strongly from any eye(More)
Larvae of the predaceous diving beetle Thermonectus marmoratus bear six stemmata on each side of their head, two of which form relatively long tubes with linear retinas at their proximal ends. The physical organization of these eyes results in extremely narrow visual fields that extend only laterally in the horizontal body plane. There are other examples of(More)
The binding of [(3)H]?-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) to synaptic membranes of rat brain was characterized in the absence of detergents and chaotropes. Optimal conditions for binding were a centrifugation assay employing a well washed, frozen-thawed synaptic membrane preparation and a 40 min incubation at 4 degrees C in 50 mM(More)
Nearly nothing is known about the transition that visual brain regions undergo during metamorphosis, except for Drosophila in which larval eyes and the underlying neural structure are strongly reduced. We have studied the larvae of the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae), which are sophisticated visually oriented(More)
Almost all animal eyes follow a few, relatively well-understood functional plans. Only rarely do researchers discover an eye that diverges fundamentally from known types. The principal eye E2 of sunburst diving beetle (Thermonectus marmoratus) larvae clearly falls into the rarer category. On the basis of two different tests, we here report that it has truly(More)
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