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Learning, brain plasticity, and foraging in hemimetabolous insects

Posted on:2012-05-28Degree:Ph.DType:Dissertation
University:Georgetown UniversityCandidate:Mallroy, Heather SeatonFull Text:PDF
GTID:1464390011466814Subject:Biology
Abstract/Summary:
Foraging is an essential component of an animal's fitness, and learning plays an important role in foraging for many animals. A deeper understanding of complex behaviors such as foraging and learning requires an interdisciplinary approach, examining both the behavior and the neurobiological underpinnings of the behaviors. Insects serve as model organisms to explore the mechanisms of foraging, learning, and memory, as they share fundamental neurobiological mechanisms with vertebrates, but have simpler nervous systems that are easier to access than vertebrate models. Drosophila, the most common insect model organism, undergoes complete metamorphosis, with a larval and adult stage that are very different in morphology and behavior. Hemimetabolous insects are emerging as new model organisms, as they undergo incomplete metamorphosis, with larval and adult stages similar in morphology and behavior. Using two hemimetabolous insects, I have examined brain plasticity, learning, and foraging using a cross-discipline approach.;Since the discovery that the brain of an adult animal can generate new neurons, studies aimed at understanding the mechanisms, stimuli, and consequences of adult brain plasticity have proliferated; however, the role that early experiences play in adult plasticity remains relatively unexplored. Using the cricket as a model organism, I show that early adulthood may be a period of particular sensitivity in insects.;I also examined foraging and learning in another hemimetabolous insect, the praying mantis. Through laboratory choice tests and a survey of an organic farm, I found that regardless of experience, flowers were not an attractant for mantises, despite the fact that mantises are often found on flowers and that fitness benefits for mantises found on flowers have been reported. Rather than an attractant, flowers may be an arrestant for mantises, which may encounter flowers through random search and then remain at the site feeding on the abundant prey.;My studies add to our understanding of foraging, learning, and brain plasticity in hemimetabolous insects, leading to a greater understanding of the underlying mechanisms that can shape an animal's behavior within a lifetime and across evolutionary time scales.
Keywords/Search Tags:Foraging, Brain plasticity, Hemimetabolous insects, Understanding, Mechanisms, Behavior
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