Retinal lesion induced plasticity in the adult rat early visual pathway [Elektronische Ressource] : an immunohistochemical study / by Olga Sumara

RETINAL LESION INDUCED PLASTICITY
IN THE ADULT RAT EARLY VISUAL PATHWAY:
AN IMMUNOHISTOCHEMICAL STUDY

by
Olga Sumara
A thesis submitted in partial fulfillment of the requirements for the degree of
Philosophiae Doctoris (PhD) in Neuroscience
from the International Graduate School of Neuroscience
Ruhr University Bochum




thAugust 16 2010








This research was conducted at the Department of Neurophysiology, within
the Faculty of Medicine at the Ruhr University under the supervision of
Prof. Dr. Ulf T. Eysel

Printed with the permission of the International Graduate School of Neuroscience, Ruhr University Bochum
Statement


I hereby certify that the dissertation at hand was completed and written independently
and without outside assistance. The "Guidelines for Good Scientific Practice"
according to § 9, Sec. 3 were adhered to. This work has never been submitted in this
or a similar form at this or any other domestic or foreign institution of higher learning
as a dissertation.






Olga Sumara
Name /Signature


thBochum, 16 August 2010















PhD Commission


Chair:

st1 Internal Examiner: Prof. Dr. Ulf T. Eysel

nd2 Internal Examiner: Prof. Dr. Klaus-Peter Hoffmann

External Examiner:

Non-Specialist:






Date of Final Examination:

PhD Grade Assigned:








TABLE of CONTENTS


TABLE of CONTENTS ................................................................................................ I 
I. List of Figures ........................................................................................................... III 
II. List of Tables ............................................................................................................ V  
III. Abbreviations ......................................................................................................... VI 
IV. Abstract ................................................................................................................ VII 
1.  Introduction ............................................................................................................ 1 
1.1.  Brain plasticity ................................................................................................ 1 
1.2.  The visual cortex as a model for brain plasticity ............................................ 2 
1.3.  Principles of the visual system ........................................................................ 3 
1.3.1.  Gross anatomy of the visual pathways..................................................... 3 
1.3.2.  Visual system organization ...................................................................... 5 
1.4.  Plasticity of cortical sensory maps ................................................................ 11 
2.  Aim of the study................................................................................................... 17 
3.  Materials and methods ......................................................................................... 19 
3.1.  Animals ......................................................................................................... 19 
3.2.  In vivo animal model of focal retinal lesions ................................................ 19 
3.2.1.  Creation of retinal lesion ........................................................................ 19 
3.2.2.  Validation of focal retinal lesions .......................................................... 20 
3.3.  Light stimulation ........................................................................................... 21 
3.4.  Perfusion fixation and histochemistry ........................................................... 21 
3.5.  Immunohistochemistry .................................................................................. 23 
3.6.  Data collection, determination of region of interest and quantifications. ..... 23 
3.7.  Data presentation. .......................................................................................... 26 
3.8.  Statistics ........................................................................................................ 26 
4.  Results .................................................................................................................. 27 
4.1.  Downregulation of immediate early genes (IEGs) as marker of the lesion
projection zone (LPZ) .............................................................................................. 27 
4.2.  GABA synthesizing enzymes are differentially affected by retinal lesions in
the visual cortex of rats. ........................................................................................... 35 
4.3.  Analysis of expression of calcium binding proteins ..................................... 41 
I4.4.  The distribution of glutamate transporters vGlut1 and vGlut2 is not changed
in the visual cortex following retinal lesions ........................................................... 48 
4.5.  Retina lesions induce changes in morphology and distribution of markers in
the dorsal lateral geniculate nucleus (LGN) ............................................................ 50 
4.6.  Summary and conclusions ............................................................................. 56 
5.  Discussion ............................................................................................................ 58 
5.1.  Summary ....................................................................................................... 58 
5.2.  Detailed discussion ........................................................................................ 59 
5.2.1.  Immediate early genes – function, classification and involvement in
neuronal plasticity ................................................................................................ 59 
5.2.2.  GABA synthesizing enzymes, GAD65 and GAD67 – role in
development, plasticity and disease. .................................................................... 64 
5.2.3.  Calcium binding proteins (CaBPs) – calbindin (CB), calretinin (CR)
and parvalbumin (PV) in the model of adult brain plasticity following
retinal lesion. ....................................................................................................... 70 
5.2.4.  Vesicular glutamate transporters (VGLUTs) and their role in synaptic
plasticity ............................................................................................................... 80 
5.3.  Conclusions ................................................................................................... 83 
6.   References ............................................................................................................ 85 
7.  Appendix ............................................................................................................ 109 
7.1. Immunochistochemistry protocol ................................................................... 109 
7.2. Curriculum Vitae ............................................................................................ 111 
7.3. List of publications ......................................................................................... 114 
7.4. Acknowledgements 115 



III. List of Figures

Figure 1.1. Scheme representing main parts of the visual pathways. ............................ 4 
Figure 1.2. Retinotopic organization in the rat using optical imaging. .......................... 5 
Figure 1.3. Scheme of the rat’s dLGN organization. ..................................................... 7 
Figure 1.4. Schematic drawing showing retinotopy and magnification factor of retinal
projection to human V1. ................................................................................................ 8 
Figure 1.5. Stratification of the visual cortex. ............................................................... 9 
Figure 1.6. The primary visual cortex has distinct anatomical layers, each with
characteristic synaptic connections. ............................................................................. 10 
Figure 1.7. A scheme representing the reorganization of the cortex after retinal lesion.
...................................................................................................................................... 12 
Figure 1.8. Effect of retinal lesions on cortical topography. ....................................... 13 
Figure 3.1. Position, shape and scheme of retinal lesions. .......................................... 20 
Figure 3.2. Shape and size of the retinal lesion and resulting cha