University of Louisville ThinkIR: The University of Louisville's Institutional Repository Electronic Theses and Dissertations 8-2011 Roles of 5HT1A receptor in CNS neurogenesis and ADAM21 in spinal cord injury. Sheila Ann Arnold 1981- University of Louisville Follow this and additional works at: https://ir.library.louisville.edu/etd Recommended Citation Arnold, Sheila Ann 1981-, "Roles of 5HT1A receptor in CNS neurogenesis and ADAM21 in spinal cord injury." (2011). Electronic Theses and Dissertations. Paper 50. https://doi.org/10.18297/etd/50 This Doctoral Dissertation is brought to you for free and open access by ThinkIR: The University of Louisville's Institutional Repository. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of ThinkIR: The University of Louisville's Institutional Repository. This title appears here courtesy of the author, who has retained all other copyrights. For more information, please contact [email protected]. ROLES OF 5HT1A RECEPTOR IN CNS NEUROGENESIS AND ADAM21 IN SPINAL CORD INJURY By Sheila Ann Arnold B.A., University of Louisville, 2003 M.S., University of Louisville, 2006 A Dissertation Submitted to the Faculty of the School of Medicine of the University of Louisville In Partial Fulfillment of the Requirements For the Degree of Doctorate of Philosophy Department of Pharmacology and Toxicology University of Louisville Louisville, Kentucky August 2011 ROLES OF 5HT1A RECEPTOR IN CNS NEUROGENESIS AND ADAM21 IN SPINAL CORD INJURY By Sheila Ann Arnold B.A., University of Louisville, 2003 M.A., University of Louisville, 2006 A Dissertation Approved on July 21, 2011 By the following Dissertation Committee: Theo Hagg, M.D., Ph.D. Evelyne Gozal, Ph.D. Michal Hetman, M.D., Ph.D. Peter P. Rowell, Ph.D. Scott R. Whittemore, Ph.D. ii DEDICATION To God, all for your glory. "The LORD is my rock, my fortress and my deliverer; my GOD is my rock, in whom I take refuge. He is my shield and the horn of my salvation, my stronghold." (Psalms 18:2) To Seth, when life gives you lemons, God helps make them the best lemonade. Always look to God for guidance, as he will never lead you astray. iii ACKNOWLEDGEMENTS I would like to thank my mentor, Theo Hagg, for his guidance not only in science but also in life. I would also like to thank my committee members for their time and assistance in this journey over the last five years. Mostly, I would like to thank my entire family, especially my parents Charles Arnold, Karen Arnold, Marcia Potts, and Tom Potts, for always being there at a moment's notice to lend a helping hand, watch Seth, talk, or just listen. Lastly, I would like to thank my wonderful son who has been patient and understanding while working on this dissertation. I know that was more patience and understanding than most six year olds possess. iv ABSTRACT ROLES OF 5HT1A RECEPTOR IN CNS NEUROGENESIS AND ADAM21 IN SPINAL CORD INJURY Sheila Ann Arnold July 21, 2011 These studies set out to identify strategies to rescue and repair the adult nervous system. First, we investigated the role of ciliary neurotrophic factor (CNTF) in SHT1A receptor-induced neurogenesis in the rodent brain. Systemic treatment with an agonist, 8-0H-DPAT, increased neurogenesis only in rats and not mice, and only in one of the two neurogenic regions. This increase was not mediated by CNTF. These data suggest that translation of SHT1A-based studies to human cell replacement therapies should be reconsidered. Secondly, the role of the plasticity-associated metalloprotease ADAM21 after spinal cord injury was investigated by comparing ADAM21-deficient mice to their wildtype littermates. No differences in behavioral or histology were found. However, a comprehensive metalloproteinase gene array revealed that ADAM21 regulates a cluster of inflammatory genes following injury. This leaves a potential for discovery of specific pharmaceutical ADAM21 inhibitors to reduce detrimental inflammatory processes following spinal cord injury. v TABLE OF CONTENTS PAGE DEDICATION ....................................................................................................... iii ACKNOWLEDGEMENTS ..................................................................................... iv ABSTRACT .......................................................................................................... v LIST OF TABLES ................................................................................................. x LIST OF FIGURES ............................................................................................... xi CHAPTER ONE ................................................................................................... 1 INTRODUCTION .............................................................................................. 1 General .......................................................................................................... 1 Neurogenesis ................................................................................................ 2 Neurodegenerative diseases ......................................................................... 4 Ciliary Neurotrophic Factor. ..... ...................................................................... 5 Serotonin ....................................................................................................... 7 Pharmacological stimulation of serotonin receptors and neurogenesis ......... 8 Spinal Cord Injury .......................................................................................... 9 The Metzincin Superfamily .......................................................................... 10 ADAM proteins ............................................................................................ 11 Metalloproteinases in Spinal cord injury ...................................................... 14 CHAPTER TWO ................................................................................................. 17 SEROTONIN 1A RECEPTOR INCREASES SPECIES- AND REGION­ SELECTIVE ADULT CNS NEUROGENESIS, BUT NOT THROUGH CNTF .. 17 INTRODUCTION ............................................................................................ 17 MATERIAL AND METHODS ........................................................................... 19 Animals ........................................................................................................ 19 5HT1A agonist treatment and BrdU injection protocols ............................... 19 vi mRNA measurements by quantitative real-time reverse transcription-PCR (qPCR) ........................................................................................................ 20 Histology ...................................................................................................... 20 Unbiased stereological counts and statistics ............................................... 22 RESULTS ....................................................................................................... 23 5HT1A receptors co-localization in SVZ astrocytes in C57BLl6J mice ........ 23 5HT1A agonist 8-0H-DPAT does not increase neurogenesis in adult C57BL/6J mice ............................................................................................ 23 8-0H-DPAT does not increase CNTF expression in C57BLl6J mice .......... 24 8-0H-DPAT does not stimulate neurogenesis or CNTF in adult 129SvEv mice ............................................................................................................. 25 8-0H-DPAT increases neurogenesis in adult rats, but only in the SGZ and not through CNTF ........................................................................................ 26 DiSCUSSiON .................................................................................................. 27 CHAPTER THREE ............................................................................................. 39 ADAM21-DEFICIENT MICE HAVE NO APPARENT PHENOTYPE BEFORE OR AFTER SPINAL CORD INJURy ............................................................... 39 INTRODUCTION ............................................................................................ 39 METHODS ...................................................................................................... 41 Animals ........................................................................................................ 41 Spinal cord injury ......................................................................................... 42 BMS analyses ............................................................................................. 42 Beam Walk analyses ................................................................................... 43 Hargreaves analyses ................................................................................... 43 Tail Flick ...................................................................................................... 44 Histology ............................................................................ , ......................... 44 Histology image analysis ............................................................................. 46 Statistical analysis ....................................................................................... 47 RESULTS ....................................................................................................... 47 ADAM21 localization ................................................................................... 47 Behavioral