title: Photoreceptor inner and outer segments.
abstract: Photoreceptors are exquisitely adapted to transform light stimuli into electrical signals that modulate neurotransmitter release. These cells are organized into several compartments including the unique outer segment (OS). Its whole function is to absorb light and transduce this signal into a change of membrane potential. Another compartment is the inner segment where much of metabolism and regulation of membrane potential takes place and that connects the OS and synapse. The synapse is the compartment where changes in membrane potentials are relayed to other neurons in the retina via release of neurotransmitter. The composition of the plasma membrane surrounding these compartments varies to accommodate their specific functions. In this chapter, we discuss the organization of the plasma membrane emphasizing the protein composition of each region as it relates to visual signaling. We also point out examples where mutations in these proteins cause visual impairment.
authors.affiliation: Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA. Electronic address: sheila-baker@uiowa.edu.
authors.forename: Sheila A
authors.initials: SA
authors.lastname: Baker
authors.forename: Vasily
authors.initials: V
authors.lastname: Kerov
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000378:metabolism; D010786:Photoreceptor Cells / Q000737:chemistry / Q000378:metabolism*; D012160:Retina / Q000033:anatomy & histology; D012243:Rhodopsin / Q000378:metabolism; D050600:SNARE Proteins / Q000378:metabolism; D015398:Signal Transduction; D019831:Sodium-Calcium Exchanger / Q000378:metabolism; D014714:Vertebrates / Q000378:metabolism
chemical_list: D015220:Calcium Channels; D054815:Cyclic Nucleotide-Gated Cation Channels; D050600:SNARE Proteins; D019831:Sodium-Calcium Exchanger; D012243:Rhodopsin
keywords: Compartmentalization; IS; Inner segment; Ion channel; OS; Outer segment; Photoreceptor; Plasma membrane; Retina; Synapse