Genealogical Correspondence of Learning and Memory Centers across Phyla

Persistent Link:
http://hdl.handle.net/10150/556847
Title:
Genealogical Correspondence of Learning and Memory Centers across Phyla
Author:
Wolff, Gabriella Hannah
Issue Date:
2015
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Embargo:
Release after 29-Apr-2016
Abstract:
Across bilaterian phyla, learning and memory allows animals to benefit from central-place foraging, return to ideal food sources, choose mates and avoid dangerous or harmful external stimuli. Although these behaviors are comparable in both vertebrate and invertebrate animals, it is unknown whether or not they are mediated by homologous brain structures. In insects, paired, lobate forebrain structures called mushroom bodies receive input from primary sensory neuropils and are necessary for learning and memory, whereas in crustaceans, this behavior is mediated by paired, compact forebrain structures called hemiellipsoid bodies. Mammalian learning and memory is mediated by the paired, horn-shaped hippocampi, which also receive sensory input and are likewise situated in the forebrain. Did these structures evolve independently along with the ability for animals to learn and remember associations and places? Alternatively, the hypothesis posited in this dissertation is that the last bilaterian ancestor already possessed the ability to learn and adapt to its environment, behavior mediated by paired forebrain structures that evolved divergently into the elaborated forms we observe in extant, crown-group taxa. This hypothesis is investigated and discussed in the following reports: 1) a review of insect brain anatomy and functional connectivity, including a description of mushroom bodies, in the context of arthropod evolution; 2) a comparison of neuroanatomy, circuitry, and protein expression between insect mushroom bodies and Malacostracan crustacean hemiellipsoid bodies, using cockroaches and Caribbean hermit crabs as representatives of their classes; 3) a deeper investigation of the fine structure of neuronal organization in the hemiellipsoid body of the Caribbean hermit crab, focusing on electron microscopical observations and comparisons to the ultrastructure of the fruit fly mushroom body; 4) a survey of four invertebrate Phyla, employing the strategy of comparing neuroanatomy and protein expression to investigate whether higher order forebrain structures in these animals were inherited from a common ancestor; 5) a comparison of neuroanatomy, connectivity, and protein expression in insect mushroom bodies and mammalian hippocampus, including a survey of PKA-Cα in these and corresponding structures across the Chordata. The total evidence suggests that a common Bilaterian ancestor possessed a center that evolved to become mushroom bodies in invertebrates and hippocampus in vertebrates.
Type:
text; Electronic Dissertation
Keywords:
hippocampus; invertebrate; learning; memory; mushroom body; Neuroscience; evolution
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Neuroscience
Degree Grantor:
University of Arizona
Advisor:
Strausfeld, Nicholas J.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleGenealogical Correspondence of Learning and Memory Centers across Phylaen_US
dc.creatorWolff, Gabriella Hannahen
dc.contributor.authorWolff, Gabriella Hannahen
dc.date.issued2015en
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.releaseRelease after 29-Apr-2016en
dc.description.abstractAcross bilaterian phyla, learning and memory allows animals to benefit from central-place foraging, return to ideal food sources, choose mates and avoid dangerous or harmful external stimuli. Although these behaviors are comparable in both vertebrate and invertebrate animals, it is unknown whether or not they are mediated by homologous brain structures. In insects, paired, lobate forebrain structures called mushroom bodies receive input from primary sensory neuropils and are necessary for learning and memory, whereas in crustaceans, this behavior is mediated by paired, compact forebrain structures called hemiellipsoid bodies. Mammalian learning and memory is mediated by the paired, horn-shaped hippocampi, which also receive sensory input and are likewise situated in the forebrain. Did these structures evolve independently along with the ability for animals to learn and remember associations and places? Alternatively, the hypothesis posited in this dissertation is that the last bilaterian ancestor already possessed the ability to learn and adapt to its environment, behavior mediated by paired forebrain structures that evolved divergently into the elaborated forms we observe in extant, crown-group taxa. This hypothesis is investigated and discussed in the following reports: 1) a review of insect brain anatomy and functional connectivity, including a description of mushroom bodies, in the context of arthropod evolution; 2) a comparison of neuroanatomy, circuitry, and protein expression between insect mushroom bodies and Malacostracan crustacean hemiellipsoid bodies, using cockroaches and Caribbean hermit crabs as representatives of their classes; 3) a deeper investigation of the fine structure of neuronal organization in the hemiellipsoid body of the Caribbean hermit crab, focusing on electron microscopical observations and comparisons to the ultrastructure of the fruit fly mushroom body; 4) a survey of four invertebrate Phyla, employing the strategy of comparing neuroanatomy and protein expression to investigate whether higher order forebrain structures in these animals were inherited from a common ancestor; 5) a comparison of neuroanatomy, connectivity, and protein expression in insect mushroom bodies and mammalian hippocampus, including a survey of PKA-Cα in these and corresponding structures across the Chordata. The total evidence suggests that a common Bilaterian ancestor possessed a center that evolved to become mushroom bodies in invertebrates and hippocampus in vertebrates.en
dc.typetexten
dc.typeElectronic Dissertationen
dc.subjecthippocampusen
dc.subjectinvertebrateen
dc.subjectlearningen
dc.subjectmemoryen
dc.subjectmushroom bodyen
dc.subjectNeuroscienceen
dc.subjectevolutionen
thesis.degree.namePh.D.en
thesis.degree.leveldoctoralen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplineNeuroscienceen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorStrausfeld, Nicholas J.en
dc.contributor.committeememberGronenberg, Wulfilaen
dc.contributor.committeememberHildebrand, John G.en
dc.contributor.committeememberNighorn, Alan J.en
dc.contributor.committeememberStrausfeld, Nicholas J.en
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