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Drosophilalarvae are an established model system for studying the mechanisms of innate and simple forms of learned behavior. They have about 10 times fewer neurons than adult flies, and it was the low total number of their neurons that allowed for an electron microscopic reconstruction of their brain at synaptic resolution. Regarding the mushroom body, a central brain structure for many forms of associative learning in insects, it turned out that more than half of the classes of synaptic connection had previously escaped attention. Understanding the function of these circuit motifs, subsequently confirmed in adult flies, is an important current research topic. In this context, we test larvalDrosophilafor their cognitive abilities in three tasks that are characteristically more complex than those previously studied. Our data provide evidence for (i) conditioned inhibition, as has previously been reported for adult flies and honeybees. Unlike what is described for adult flies and honeybees, however, our data do not provide evidence for (ii) sensory preconditioning or (iii) second-order conditioning inDrosophilalarvae. We discuss the methodological features of our experiments as well as four specific aspects of the organization of the larval brain that may explain why these two forms of learning are observed in adult flies and honeybees, but not in larvalDrosophila.
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This content will become publicly available on June 12, 2025
Drosophila Late Embryonic through Late Larval Stage Body Wall Dissection: Dissection Tools and Techniques
One of the challenges of studying synaptic structure and function is accessibility. Some of the earliest readily identifiable and accessible synapses were from the frog and various arthropods. To address questions regarding mechanisms that underlie synaptic development and function, genetically tractable systems were required, and researchers turned to theDrosophila melanogasterembryonic/larval neuromuscular preparation.Drosophilaembryos are transparent and can be labeled with antibodies or probes and imaged in whole-mount preparation for structural analysis. Embryos can also be dissected to visualize the entire body wall musculature as well as finer details including live protein trafficking and protein–protein interactions. Whereas younger dissected embryos can be mounted directly onto charged slides, more mature embryos and larvae develop a cuticle that impedes this adherence, so different techniques must be applied. In this protocol, we detail how to manufacture dissection tools and collect embryos, and discuss the individual steps of dissecting late-stage embryos, early first-instar larvae, and late-stage third-instar larvae.
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- Award ID(s):
- 2048080
- PAR ID:
- 10564820
- Publisher / Repository:
- Cold Spring Harbor Laboratory Press
- Date Published:
- Journal Name:
- Cold Spring Harbor Protocols
- ISSN:
- 1940-3402
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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