Contents
Abstract ii
Acknowledgments iii
Listoflllustrations vii
List of Tables viii
1 Introduction 1
1.1 Motivation..................................... . 1
1.2 Background ...................................... 5
1.2.1 Ih and HCN Channels . .......................... 6
1.2.2 ElectricalCouplingintheRetina ..................... 9
2 Materials and Methods 11
2.1 Materials............ 11
2.2 Solutions........................................ 12
2.3 Recordings...................................... 13
2.4 Immunohistochemistry and Western Blot..................... 16
2.5 Data analysis...................................... 18
2.6 Numerical Methods.................................. 21
3 Properties and Function of HCN Channels in Photoreceptors 22
3.1 Introduction....... 22
3.2 MolecularandBiophysicalProperties........... 24
3.2.1 Whole-cell currents . ............................ 24
3.2.2 Distribution and Molecular Identification................ 27
3.2.3 HcNlsinglechannelconductance.................... 30
3.3 FunctionofHcNchannelsinphotoreceptors.................. 34
3.3.1 SimulatedHcNcurrentduringrodlightresponse........... 34
3.3.2 HCN contribution to photoreceptor membrane frequency response 37
3.3.3 Equivalent circuit........... 39