Time Course of Neuronal Degeneration in the Pilocarpine Model of Epileptogenesis

............................................................................................................................................. ix .A CICYOWLEDGEME?jTS ...................................................................................................................... x ...................................... CHAPTER 1 . RESEARCH GOALS AL YD LITERATURE REVIEN'....*..... 1 .......................................................................................................................................... 1.1 EPILEPSY 3 ...................................................................................................... 1 . L TEMPORAL LOBE EPILEPSY 4 1.3 TEMPORAL LOBE EPPLEPSY: A N M M MODELS ................................................................... 5 ...................................................................................................... 1 2 . 1 Chrimicall y-Induced Seizures 5 1.32 Cliolinornimetics ........................................................................................................................ 6 ................................................................................................................................... 1.3.3 Pilocarpine 7 1.4 EPLEPTOGENESIS: THE DEVELOPMENT OF EPiLEPSY .................................................... 10 .................................................................................................................................... 1.4.1 Ce11 Loss 10 1 .4.2 Auon Sprouting ......................................................................................................................... 12 1.4.3 Gliosis ...................................................................................................................................... 12 ..................................................................................................................... 1.4.4 Dendrit ic Changes 13 1 A.5 Impaired Inhibition .................................................................................................................... 13 1.5 ANATOMY OF TEMPORAL LOBE: THE HiPPOC,4iiP.IV. FORMATION AS A FOCUS OF EPILEPTOGENESIS .............................................................................................................................. 15 ............................................................................................................ 1.5.1 Hippocarnpal Formation 16 1 . 5.2 Principal Neurons ...................................................................................................................... 16 1.5.3 Local Circuit Interneurons ........................................................................................................ 17 ............................................................................................. ............ 1.5.3 Hippocampal Sectors .. 19 1.6. NEURONAL DEGENEUTION DURNG EPILEPTOGENESIS: HISTOLOGICAL MARKERS ............................................................................................................................................. 21 7 3 .................................................................................................. 1.6.1 Histological Stains: Principles -1 .6.2 Dark Neuron Stain : Marker of Reversible Cellular Damage ................................................... 24 1.6.3 Anionic Dyes: Principles .......................................................................................................... 27 1.6.4 Fluoro-Jade: Marker of Lrreversible Cellular Damage ...... ................................................... 2 9 PREFACE TO CHAPTER 2 .................... . ........ .. ..... . . . . .................. 3 1 CHAPTER 2 . DEFERENTIAL PROGRESSION OF DARK NEURON .L YD FLUORO-J.mE LABELLING I3 THE RAT HIF'POCAbIPUS FOLLOWIirJG PtLOCARPM-LXDUCED .................. STATUS EPILEPTICUS ....... .. . . . . . . . . . . . . . . . . m e . . . . . 3 2 -I -I ..................................................................................................................................... 2.1 .I\LB STMCT 33 ............................................................................................................................ 2.2 INTRODUCTION 35 ................................................................................................ 2.3 EXPERIMENTAL PROCEDURES 36 2.3.1 Pilocarpine induced status epilepticus ....................................................................................... 36 ............................................................................................................ 2 . 3 2 Behavioural Monitoring 36 7 . ............................................................................................................. 2.3.3 Flution and Sectioning 37 1 7 ..................................................................................................................... 2.2.4 Derk Xeuron S!zic J , ................................................................................................................................ 2.3.5 Fluoro-Jade 37 2.3.6 Neuron and GIial specific labelling ......................................................................................... 3s ............................................................................................................................ 2.3 -7 Quantitication 38 ....................................................................................................................... 2.3.8 Dissector Method 39 2.3.9 Statistical tests ...................................................................................................................... 1 0 3.4 RESLXTS ........................................................................................................................................ 41 2.4.1 Behavioural ................................................................................................................................ 41 2.4.2 Pattern of Dark Neuron labelling ............................................................................................... 41 2 .43 Time Course of Dark Neuron and Fluoro-Jade labelling .......................................................... I 3 2.4.4 Progression of Cell Loss and Gliosis ......................................................................................... 43 2.5 DISCUSSION .................................................................................................................................. I 4 ............................................................................................................. 2.6 ACEOIOWLEDGEMENTS I S CHAPTER 3 . DISCUSS103 ................................. ......... ................................................................... 68 ....................................................................................................................... 3.1 Summary of Findings 69 3.2 Scope of our findings ...................................................................................................................... 70 .............................................................................................................................. 3.3 Future Directions 72 3.4 Conciusion ........................................................................................................................................ 74 REFERENCES .............. . ........e~....~................................~..........................~.......~..............~..................... 75 PREFA CE Candiates have the option of including, as part of the thcsis. the trxt of one or more papers submitted or to be submitted for publication. or the clearly-duplicated text of one or more published papers. T'hese texts must be bound as an integral part of the thesis. If this option is chosen, connectinp trxts that pro~ide logical bridges brtwecn the different papers are mandatory. The thesis must be written in such a way that it is more than a mere coilection of manuscripts: in other words. results of a series of papèrs must br integrated. The thrsis must still conform to al1 other requirements of the "Guidelines for Thesis Prepantion". The thesis must include: A Table of