Analysis of olfaction-driven locomotor behavior of Drosophila melanogaster larvae
Loading...
Authors
Odell, Seth
Issue Date
2022
Type
Dissertation
Language
Keywords
Individuality , Olfaction , Optogenetics
Alternative Title
Abstract
The survival of many animals is dependent on their ability to navigate their environment to find food. Information about food sources is typically conveyed by olfactory information. The olfactory system is crucial to animal survival. However, the manner in which olfactory inputs are translated to behavioral outputs is unclear. To elucidate this process, I examined the olfactory behaviors in Drosophila melanogaster third instar larvae. By examining the important of several components of the peripheral olfactory circuit, I uncovered their contributions to navigational behavior. Stimulation of first-order olfactory sensory neurons (OSNs) reveals that the behavioral outputs can be categorized into a handful of groups. Optogenetic stimulation of the OSNs reveals a temporal aspect of behavioral outputs. Some OSNs responded to stimulus increments and other responded to stimulus decrements. Next, the contributions of a single, paired modulatory local neuron (LN) to search behavior were examined. Stimulation of this neuron, Keystone-LN, led to head sweeping behavior. Head sweeps are a crucial component of search behavior. This behavior was also modulated by the satiety state of the animal. I also show evidence that insulin-signaling is likely mediating this behavior. Adjusting insulin signaling in Keystone-LN alone is sufficient to cause a shift in the search behavior of the larvae. Finally, I examined the role of individuality in the larvae. Individuality was assayed by determining the presence of a behavioral syndrome. I find that behavioral syndromes in the larvae are stable over short developmental time frames. Furthermore, different traits are stable over different internal and external situations. Taken together, this research shows how these peripheral olfactory circuit components are contributing to navigational behavior of the Drosophila larvae.