title: HCN channels are expressed differentially in retinal bipolar cells and concentrated at synaptic terminals.
abstract: Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels codetermine the integrative behaviour of neurons and shape their response to synaptic stimulation. We used immunohistochemistry and patch-clamp recording to study the composition and distribution of HCN channels in the rat retina. All four HCN channel isoforms (HCN1-4) are expressed differentially in the retina. In particular, different classes of bipolar cells have a different inventory of HCN channels. We found no evidence for the formation of heterooligomeric HCN channels. HCN channels are densely clustered at synaptic terminals of bipolar cells and photoreceptors. This suggests that HCN channels are involved in the control of transmitter release.
authors.affiliation: Institut für Biologische Informationsverarbeitung, Forschungszentrum Jülich, D-52425 Jülich, Germany. f.mueller@fz-juelich.de
authors.forename: Frank
authors.initials: F
authors.lastname: Müller
authors.forename: Alexander
authors.initials: A
authors.lastname: Scholten
authors.forename: Elena
authors.initials: E
authors.lastname: Ivanova
authors.forename: Silke
authors.initials: S
authors.lastname: Haverkamp
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kremmer
authors.forename: U Benjamin
authors.initials: UB
authors.lastname: Kaupp
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D054815:Cyclic Nucleotide-Gated Cation Channels; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D007150:Immunohistochemistry; D007473:Ion Channels / Q000032:analysis / Q000276:immunology / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D008854:Microscopy, Electron; D009124:Muscle Proteins / Q000032:analysis / Q000276:immunology / Q000502:physiology; D015221:Potassium Channels / Q000032:analysis / Q000276:immunology / Q000502:physiology; D017729:Presynaptic Terminals / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D012160:Retina / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D054815:Cyclic Nucleotide-Gated Cation Channels; C578665:HCN1 protein, human; C472018:HCN3 protein, human; C119587:HCN4 protein, human; C578667:Hcn1 protein, rat; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D007473:Ion Channels; D009124:Muscle Proteins; D015221:Potassium Channels