Direct rod input to cone BCs and direct cone input to rod BCs challenge the traditional view of mammalian BC circuitry
Year: 2009
Type: article
Abstract: Bipolar cells are the central neurons of the retina that transmit visual signals from rod and cone photoreceptors to third-order neurons in the inner retina and the brain. A dogma set forth by early anatomical studies is that bipolar cells in mammalian retinas receive segregated rod/cone synaptic inputs (either from rods or from cones), and here, we present evidence that challenges this traditional view. By analyzing light-evoked cation currents from morphologically identified depolarizing bipolar cells (DBCs) in the wild-type and three pathway-specific knockout mice (rod transducin knockout [Tralpha(-/-)], connexin36 knockout [Cx36(-/-)], and transcription factor beta4 knockout [Bhlhb4(-/-)]), we show that a subpopulation of rod DBCs (DBC(R2)s) receives substantial input directly from cones and a subpopulation of cone DBCs (DBC(C1)s) receives substantial input directly from rods. These results provide evidence of the existence of functional rod-DBC(C) and cone-DBC(R) synaptic pathways in the mouse retina as well as the previously proposed rod hyperpolarizing bipolar-cells pathway. This is grounds for revising the mammalian rod/cone bipolar cell dogma.
Authors: Ji-Jie Pang, Fan Gao, Janis Lem, Debra E. Bramblett, David L. Paul, Samuel M. Wu
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: G1247374287, G2154435854, Genetic Mechanisms of Retinal Degenerative Disease, Connexins and electrical synapses in the retina, G3921241088, G5434259422, P30 - Core Grant for Vision Research, PHYSIOLOGY AND PHARMACOLOGY OF SYNAPSES IN THE RETINA, G6088426338, Rod and cone signaling pathways in mammalian retina, G9000112642, G959450305
OpenAlex ID: W2064350082