HCN channels are expressed differentially in retinal bipolar cells and concentrated at synaptic terminals.
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.
Müller
Frank
F
Institut für Biologische Informationsverarbeitung, Forschungszentrum Jülich, D-52425 Jülich, Germany. f.mueller@fz-juelich.de
Scholten
Alexander
A
Ivanova
Elena
E
Haverkamp
Silke
S
Kremmer
Elisabeth
E
Kaupp
U Benjamin
UB
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
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