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THE DEVELOPMENT OF EXCITATORY SYNAPSES AND COMPLEX BEHAVIOR · PDF file THE DEVELOPMENT OF EXCITATORY SYNAPSES AND COMPLEX BEHAVIOR by JENNIFER LYN HOY A DISSERTATION Presented to

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  • THE DEVELOPMENT OF EXCITATORY SYNAPSES AND COMPLEX BEHAVIOR

    by

    JENNIFER LYN HOY

    A DISSERTATION

    Presented to the Department of Biology

    and the Graduate School of the University of Oregon

    in partial fulfillment of the requirements

    for the degree of

    Doctor of Philosophy

    September 2011

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    DISSERTATION APPROVAL PAGE

    Student: Jennifer L Hoy

    Title: The Development of Excitatory Synapses and Complex Behavior

    This dissertation has been accepted and approved in partial fulfillment of the

    requirements for the Doctor of Philosophy degree in the Department of Biology by:

    William Roberts Chairperson

    Philip Washbourne Advisor

    Victoria Herman Member

    Michael Wehr Member

    Judith Eisen Member

    Clifford Kentros Outside Member

    and

    Kimberly Andrews Espy Vice President for Research & Innovation/Dean of the

    Graduate School

    Original approval signatures are on file with the University of Oregon Graduate School.

    Degree awarded September 2011

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    © 2011 Jennifer Lyn Hoy

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    DISSERTATION ABSTRACT

    Jennifer Lyn Hoy

    Doctor of Philosophy

    Department of Biology

    September 2011

    Title: The Development of Excitatory Synapses and Complex Behavior

    Approved: _______________________________________________

    Philip Washbourne

    Excitatory glutamatergic synapses facilitate important aspects of communication

    between the neurons that govern complex forms of behavior. Accordingly, small

    differences in the molecular composition of glutamatergic synapses have been suggested

    to underlie neurodevelopment disorders, drive evolutionary changes in brain function and

    behavior, and enhance specific aspects of cognition in mammals. The appropriate

    development and later function of these structures in the adult involves the well-

    coordinated activities of hundreds of molecules. Therefore, an important goal in

    neuroscience is to identify and characterize how specific molecules contribute to the

    development of excitatory synapses as well as how manipulations of their function

    impact neural systems and behavior throughout life. This dissertation describes two

    important contributions toward this effort, 1) that the newly discovered molecule,

    Synaptic Cell Adhesion Molecule 1 (SynCAM1) specifically contributes to the early

    stages of glutamatergic synapse formation and 2) that Neuroligin1 (NL1) contributes to

    the mature function of glutamatergic synapses and mature forms of behavior in vivo.

    In the first set of experiments, I developed an in vitro cell based assay in order to

    determine the minimal molecular components necessary to recruit developmentally

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    relevant glutamate receptor subtypes to sites of adhesion mediated by SynCAM1. In

    these experiments we discovered that protein 4.1B interacted with SynCAM1 in order to

    cause the specific recruitment of the NMDA type glutamate receptor containing the

    NR2B subunit. In the second set of experiments, we show that expression of NL1 missing

    the terminal 55 amino acids enhanced short term learning and flexibility in behaving

    mice while increasing the number of immature excitatory postsynaptic structures.

    Interestingly, this behavioral profile had components more consistent with 1 month old

    juvenile controls than age matched control littermates. In contrast, full length NL1

    overexpression impaired learning and enhanced perseverance while yielding an increase

    in the proportion of synapses with mature characteristics. These results suggest that

    NL1‟s C-terminus drives the synaptic maturation process that shapes the development of

    complex behavior. Both studies bolster our understanding of how specific molecules

    impact the development of excitatory synapses and complex behavior.

    This dissertation includes both my previously published and unpublished co-

    authored material.

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    CURRICULUM VITAE

    NAME OF AUTHOR: Jennifer Lyn Hoy

    GRADUATE AND UNDERGRADUATE SCHOOLS ATTENDED:

    University of Oregon, Eugene

    University of Arizona, Tucson

    DEGREES AWARDED:

    Doctor of Philosophy, Biology 2011, University of Oregon

    Bachelor of Science, Molecular and Cellular Biology, 2003, University of

    Arizona

    AREAS OF SPECIAL INTEREST:

    Neuroscience

    Genetics and Behavior

    GRANTS, AWARDS, AND HONORS:

    Oregon Center for the Optics (OCO) Integrative science proposal award,

    Novel Strategies for Enhanced Quantitative Characterization of Mouse Behavior

    in Standard Learning and Memory Tests, University of Oregon, 2010

    Women in Graduate Science (WGS) travel award Society for Neuroscience,

    University of Oregon, 2009

    NIH/APA DPN pre-doctoral fellowship: 5 T32 MH18882, Development of

    Excitatory Synapses and Learning and Memory, University of Oregon, 2006

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    PUBLICATIONS:

    Hoy J.L., Constable, J.R.L., Arias R.J., Chebac R., Kyweriga M., Schnell E., Davis L.,

    Wehr M., Washbourne P.E. (2011) The intracellular region of NL1 regulates behavioral

    and synaptic maturation (Submitted to Neuron).

    Hoy J.L., Constable, J., Vicini S., Fu Z., Washbourne P.E. (2009) SynCAM1 recruits

    NMDA receptors via Protein 4.1B. Mol Cell Neurosci 42:466-483

    http://www.ncbi.nlm.nih.gov/pubmed/19796685?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum http://www.ncbi.nlm.nih.gov/pubmed/19796685?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

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    ACKNOWLEDGMENTS

    I wish to express sincere appreciation to my advisor Philip Washbourne for his

    support and guidance in conducting this research, generously providing outside training

    where necessary and help in preparing the manuscripts. It has been an invaluable training

    experience to watch him establish his lab. I greatly value the contributions of all of my

    committee members, Bill Roberts, Judith Eisen, Tory Herman, Mike Wehr and Cliff

    Kentros. Their thoughts and criticisms were important to this work and my progress. I

    also appreciate that Peg Morrow, Ellen McCumsey, Mike McHorse, Don Pate, Mikel

    Rhodes and Donna Overall being so good at what they do ensured that I stayed physically

    healthy and paid on time. The support and early “training” that came from many family

    members, principally my mother and stepfather, my aunt and uncle, and grandparents,

    was also critical in allowing me to accomplish this task. This work was funded in part by

    Autism speaks, the NINDS (RO1 NS065795), and the NIH and the APA (5 T32

    MH18882).

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    Dedicated to my mother, who taught me to observe the beauty in all of life and how to

    persevere, and to my husband who harbors the same wonder in the way of the world.

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    TABLE OF CONTENTS

    Chapter Page

    I. INTRODUCTION .................................................................................................... 1

    II. THE NOVEL CELL ADHESION MOLECULE SYNCAM1 CONTRIBUTES

    TOWARDS THE EARLY DEVELOPMENTAL STAGES OF GLUTAMATERGIC

    SYNAPSE FORMATION: SYNCAM1 RECUITS NMDA RECEPTORS VIA

    PROTEIN 4.1B ........................................................................................................... 4

    1. Introduction ....................................................................................................... 4

    2. Results ............................................................................................................... 6

    3. Discussion ......................................................................................................... 30

    4. Methods ............................................................................................................. 34

    III. THE INTRACELLULAR REGION OF NL1 REGULATES BEHAVIORAL

    AND SYNAPTIC MATURATION ........................................................................... 44

    1. Introduction ........................................................................................................ 44

    2. Results ................................................................................................................ 46

    3. Discussion .......................................................................................................... 72

    4. Methods.............................................................................................................. 79

    IV. CONCLUSIONS ................................................................................................... 86

    APPENDICES ............................................................................................................. 89

    A. SUPPLEMENTAL MATERIAL FOR CHAPTER II ............

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