title: Synaptic connections of calbindin-immunoreactive cone bipolar cells in the inner plexiform layer of rabbit retina.
abstract: In the mammalian retina, information concerning various aspects of an image is transferred in parallel, and cone bipolar cells are thought to play a major role in this parallel processing. We have examined the synaptic connections of calbindin-immunoreactive (IR) ON cone bipolar cells in the inner plexiform layer (IPL) of rabbit retina and have compared these synaptic connections with those that we have previously described for neurokinin 1 (NK1) receptor-IR cone bipolar cells. A total of 325 synapses made by calbindin-IR bipolar axon terminals have been identified in sublamina b of the IPL. The axons of calbindin-IR bipolar cells receive synaptic inputs from amacrine cells through conventional synapses and are coupled to putative AII amacrine cells via gap junctions. The major output from calbindin-IR bipolar cells is to amacrine cell processes. These data resemble our findings for NK1 receptor-IR bipolar cells. However, the incidences of output synapses to ganglion cell dendrites of calbindin-IR bipolar cells are higher compared with the NK1-receptor-IR bipolar cells. On the basis of stratification level and synaptic connections, calbindin-IR ON cone bipolar cells might thus play an important role in the processing of various visual aspects, such as contrast, orientation, and approach sensing, and in transferring rod signals to the ON cone pathway.
authors: Department of Anatomy, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Korea.
authors: Shin Ae
authors: SA
authors: Kim
authors: Choong Ki
authors: CK
authors: Jung
authors: Tae-Hoon
authors: TH
authors: Kang
authors: Ji Hyun
authors: JH
authors: Jeon
authors: Jiook
authors: J
authors: Cha
authors: In-Beom
authors: IB
authors: Kim
authors: Myung-Hoon
authors: MH
authors: Chun
mesh_terms: D025042:Amacrine Cells / Q000648:ultrastructure; D000818:Animals; D001369:Axons / Q000502:physiology; D064026:Calbindins; D003712:Dendrites / Q000502:physiology; D017629:Gap Junctions / Q000502:physiology; D011817:Rabbits; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D051245:Retinal Bipolar Cells / Q000502:physiology* / Q000648:ultrastructure; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology* / Q000648:ultrastructure; D012165:Retinal Ganglion Cells / Q000648:ultrastructure; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D064026:Calbindins; D018040:Receptors, Neurokinin-1; D064030:S100 Calcium Binding Protein G