University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2014 Molecular-Genetic Mechanisms of Memory Formation in Mouse Models of Neurodevelopmental and Neuropsychiatric Disorders Hannah Schoch University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Neuroscience and Neurobiology Commons Recommended Citation Schoch, Hannah, "Molecular-Genetic Mechanisms of Memory Formation in Mouse Models of Neurodevelopmental and Neuropsychiatric Disorders" (2014). Publicly Accessible Penn Dissertations. 1435. https://repository.upenn.edu/edissertations/1435 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/1435 For more information, please contact [email protected]. Molecular-Genetic Mechanisms of Memory Formation in Mouse Models of Neurodevelopmental and Neuropsychiatric Disorders Abstract Neurodevelopmental and neuropsychiatric disorders are a significant and expanding global health crisis. Many individuals affected by these disorders have social and cognitive symptoms represent significant sources of ongoing disability that are refractory to available treatment options. The search for cures and therapies for disorders fundamentally requires an understanding of the core neuropathology and insight into the underlying molecular mechanisms at work. In this dissertation, I describe experiments that we performed to explore molecular and genetic mechanisms underlying memory impairment and enhancement in mice. Synaptic structural proteins form a critical and adjustable framework that supports recruitment of neurotransmitter receptors and facilitates signal transduction. In Chapter 2, we explored a role for the autism-related gene Protocadherin 10 (Pcdh10) as a key regulator of dendritic spine morphology and synapse elimination. We found that mice with reduced PCDH10 have deficits in amygdala function, including impairments in conditioned fear, social interactions and gamma synchrony, as well as increased density of immature filopodia-type spines. In the second part of this dissertation, we showed that the co-repressor SIN3A is a negative regulator of memory formation. In Chapter 3, we demonstrated that reducing levels of SIN3A enhances in long-term memory and hippocampal synaptic plasticity, and increases expression of Homer1, a gene encoding a post-synaptic density protein that regulates signaling through metabotropic glutamate receptors. In Chapter 4, we identified contextual earf deficits in transgenic mice expressing Cre recombinase in forebrain neurons. These results expand our understanding of molecular mechanisms of memory formation, and identify new therapeutic targets for improving cognitive function. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Cell & Molecular Biology First Advisor Ted Abel Keywords epigenetics, Homer1, memory formation, mouse models, Pcdh10, Sin3a Subject Categories Neuroscience and Neurobiology This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/1435 MOLECULAR-GENETIC MECHANISMS OF MEMORY FORMATION IN MOUSE MODELS OF NEURODEVELOPMENTAL AND NEUROPSYCHIATRIC DISORDERS Hannah Schoch A DISSERTATION in Cell and Molecular Biology Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2014 Supervisor of Dissertation _______________ __________ Ted Abel, Ph.D. Brush Family Professor of Biology Graduate Group Chairperson _________________________ Dan Kessler, Ph.D. Associate Professor of Cell and Developmental Biology Dissertation Committee Marisa Bartolomei, Ph.D. Professor of Cell and Developmental Biology Teresa Reyes, Ph.D. Assistant Professor of Pharmacology Peter Klein, MD, Ph.D. Professor of Medicine Tracy Bale, Ph.D. Professor of Neuroscience in Psychiatry ACKNOWLEDGMENT This journey entailed many thousand miles, yet it did not start with one particular step. It was only through the careful guidance of many that I found myself on this path, and only through the patient support of a hundred more was able to reach this point in my journey. Truly, this is not the end of the journey, but only a pause at the top of a hill to look back and appreciate the magnificence of the forest that I may have missed in my scramble to reach the next tree. Much of my success I owe to the support and guidance of Ted Abel. He stuck with me through my early years when I broke everything that I touched (RIP Gs alpha mice) and opened new doors for me to follow my obsession with developmental disorders. Ted taught me so many important life lessons- how to stop doing experiments and THINK, how to peel back the fancy tools to expose the soft center of what is actually being measured, and how to stand tall and be confident in my understanding and interpretation of my results. I will go on to my next adventure well prepared for the challenges ahead. T-6 years to the RO1. I also want to express my sincere appreciation for all the help and guidance I received from my thesis committee members, Marisa, Teresa, Peter and Tracy. Through the rocky start of my dissertation research, and the continual struggles with the Sin3a mouse, you provided constant support and encouragement along the way. As a result of your guidance, I’ve gained a wealth of perspective on how terrible quadruple transgenic mice are, an appreciation of the importance of properly controlled experiments, and a newfound respect for the horrifying effects of nuclease activity on the brain. I will carry this with me always. To the Abel lab- you have had my back for the past 7 years and it’s been one heck of a ride. Through all of the frustration and heartbreak of science, it’s the community of fellow travelers that gets you through. Whether you need another soul who understands how it is to emerge from the ii mouse facility after your 1,068th trial of water maze, or the sympathetic ear of someone who has also watched their research project crash and burn, they always know that what you really need is a funny video or a strategic application of tape to the back of your shirt. By maintaining a high level of foolishness and camaraderie in the lab, the p values of 0.06 are a little easier to accept. Thank you. I want to especially thank Jen and Nicola for their help with building this dissertation your faith in my abilities may not have entirely been misplaced. I am especially grateful for the help and support of my buddy Morg. You’ve stuck with me through the ups and downs, and further downs of the Sin3a project. Together we tamed the devil mouse and extracted his dark secrets. Thanks, buddy. Finally, I am incredibly grateful for my family. For my mom, who encouraged me to go into science, my dad who piqued my interest in the natural world, my brothers and sisters and sister- in-law and nieces and aunts uncles and grandparents who support me on this crazy path that I’m on, and also my cat Bill who stays up with me when I’m trying to hit a deadline. For my archnemesis, Dave, who stuck with me through all the late nights and crazy weeks. He always knew that I would make it here someday. Thank you for your patience and understanding. iii ABSTRACT MOLECULAR-GENETIC MECHANISMS OF MEMORY FORMATION IN MOUSE MODELS OF NEURODEVELOPMENTAL AND NEUROPSYCHIATRIC DISORDERS Hannah Schoch Ted Abel Neurodevelopmental and neuropsychiatric disorders are a significant and expanding global health crisis. Many individuals affected by these disorders have social and cognitive symptoms represent significant sources of ongoing disability that are refractory to available treatment options. The search for cures and therapies for disorders fundamentally requires an understanding of the core neuropathology and insight into the underlying molecular mechanisms at work. In this dissertation, I describe experiments that we performed to explore molecular and genetic mechanisms underlying memory impairment and enhancement in mice. Synaptic structural proteins form a critical and adjustable framework that supports recruitment of neurotransmitter receptors and facilitates signal transduction. In Chapter 2 , we explored a role for the autism-related gene Protocadherin 10 ( Pcdh10 ) as a key regulator of dendritic spine morphology and synapse elimination. We found that mice with reduced PCDH10 have deficits in amygdala function, including impairments in conditioned fear, social interactions and gamma synchrony, as well as increased density of immature filopodia-type spines. In the second part of this dissertation, we showed that the co-repressor SIN3A is a negative regulator of memory formation. In Chapter 3, we demonstrated that reducing levels of SIN3A enhances in long-term memory and hippocampal synaptic plasticity, and iv increases expression of Homer1 , a gene encoding a post-synaptic density protein that regulates signaling through metabotropic glutamate receptors. In Chapter 4 , we identified contextual fear deficits in transgenic mice expressing Cre recombinase in forebrain neurons. These results expand our understanding of molecular mechanisms of memory formation, and identify new therapeutic targets for improving cognitive function. v TABLE OF CONTENTS Contents ACKNOWLEDGMENT ............................................................................................................... II ABSTRACT .................................................................................................................................