Ectopic synaptic ribbons in dendrites of mouse retinal ON- and OFF-bipolar cells

  title={Ectopic synaptic ribbons in dendrites of mouse retinal ON- and OFF-bipolar cells},
  author={Masaaki Ishii and Katsuko Morigiwa and M. Takao and Shigetada Nakanishi and Yutaka Fukuda and Osamu Mimura and Yoshihiko Tsukamoto},
  journal={Cell and Tissue Research},
  pages={355 - 375}
The ectopic distribution of synaptic ribbons in dendrites of mouse retinal bipolar cells was examined by using genetic ablation of metabotropic glutamate receptor subtype 6 (mGluR6), electron microscopy, and immunocytochemistry. Ectopic ribbons were observed in dendrites of rod and ON-cone bipolar cells in the mGluR6-deficient mouse but not in those of wild-type mice. The number of rod spherules facing the ectopic ribbons in mGluR6-deficient rod bipolar dendrites increased gradually during… 

Effects of mGluR6-deficiency on photoreceptor ribbon synapse formation: Comparison of electron microscopic analysis of serial sections with random sections

The mGluR6-KO phenotype showed negative effects on ribbon synapse formation, and the detailed manners and degrees of alterations appeared to vary depending on different missing components, as well as structural parameters such as ribbon surface area.

Helical Fasciculation of Bipolar and Horizontal Cell Neurites for Wiring With Photoreceptors in Macaque and Mouse Retinas

How these neurites are mutually arranged to coordinate formation and maintenance of the postsynaptic complex of ribbon synapses in mouse and monkey retinas is revealed and novel helical coils of HC processes surrounding the rod BC dendrite are identified.

Functional allocation of synaptic contacts in microcircuits from rods via rod bipolar to AII amacrine cells in the mouse retina

This allocation of RB–AII synaptic contacts may serve as the structural basis for the physiological properties of the AII single‐photon response that include high amplification, local adaptation, and regenerative acceleration.

The TRPM1 Channel Is Required for Development of the Rod ON Bipolar Cell-AII Amacrine Cell Pathway in the Retinal Circuit

It is found that the TRPM1 transduction channel is required for the development of rod bipolar cells and their synaptic formation with subsequent neurons, independently of glutamate transmission.

Nyctalopin is required for localization of the TRPM1 channel to the retinal depolarizing bipolar cell dendrites


mGluR6 deletion renders the TRPM1 channel in retina inactive.

It is shown that the rod bipolar cells in mGluR6-null mice were hyperpolarized, and it is speculated that, to be constitutively active, TRPM1 channels in ON bipolar cells have to be in a complex, or perhaps require an unidentified factor.

Mechanistic Basis for G Protein Function in ON Bipolar Cells

This chapter presents the evidence that established Gαo, Gβ3, and Gγ13 as Go’s subunits in ON bipolar cells, and indicates that the different subunits also contribute to maintaining the synaptic integrity, at both the molecular and structural levels.

mGlu receptors in the retina

MGluRs appear to play a trophic role in development and after retinal damage, suggesting potential future therapeutic implications and since most of the mGluR subtypes are present in amacrine and ganglion cells that belong to many cell types, the pathways downstream of mGLURs are highly diverse with primarily modulatory effects.

Lack of mGluR6‐related cascade elements leads to retrograde trans‐synaptic effects on rod photoreceptor synapses via matrix‐associated proteins

It is proposed that the mGluR6 macromolecular complex is connected to the presynaptic rod terminal via a protein chain that includes the matrix‐associated proteins, suggesting a retrograde trans‐synaptic effect.

The Transduction Cascade in Retinal ON-Bipolar Cells: Signal Processing and Disease.

Our robust visual experience is based on the reliable transfer of information from our photoreceptor cells, the rods and cones, to higher brain centers. At the very first synapse of the visual



A Novel Connection between Rods and ON Cone Bipolar Cells Revealed by Ectopic Metabotropic Glutamate Receptor 7 (mGluR7) in mGluR6-Deficient Mouse Retinas

It is shown that a certain type of ON cone bipolar cell forms ribbon-associated synapses not only with cones, but also rods, which suggest that, in mice, rod signals bifurcate into a third ON and OFF pathway, thought to transmit fast and moderately light-sensitive rod signals, functioning to smooth out the intensity changes at the scotopic–mesopic interface.

Transient synaptic ribbons in the mammalian retina at unusual sites

It is concluded that the cell processes revealing the temporary presence of SRs are processes of flat bipolar cells which may provide a feedback to cones during the light phase.

Adaptation-dependent plasticity of rod bipolar cell axon terminal morphology in the rat retina

Observations are discussed in the context of activity-related morphological plasticity of central nervous system synapses and of the functions of PKC in the cycle of vesicle fusion and retrieval at the tonically active ribbon synapses of the rod bipolar axon terminal.

Types of bipolar cells in the mouse retina

The morphology of bipolar cells in fixed vertical tissue sections of the mouse retina is studied by injecting the cells with Lucifer Yellow and Neurobiotin and the bipolar cell types described here were compared with previous schemes of rat and primate bipolar cells.

Development and regulation of dendritic stratification in retinal ganglion cells by glutamate-mediated afferent activity

The time course of dendritic stratification in developing beta cells, the largest class of ganglion cells in the cat retina, is examined by retrograde labeling of fixed tissue with Dil, finding that short-term APB treatment causes a delay rather than a permanent arrest of the stratification process.

Plasticity of retinal ribbon synapses

The presently reviewed results suggest that SR's do not primarily function as conveyor belts, but are devices to immobilize SV's in inactive ribbon synapses, as reflected in changes in number, size, shape, location, and grouping pattern.

Immunohistological Studies of Metabotropic Glutamate Receptor Subtype 6-Deficient Mice Show No Abnormality of Retinal Cell Organization and Ganglion Cell Maturation

Immature retinal ganglion cells (RGCs) initially show a multistratified dendritic pattern, and, during the postnatal period, these dendrites gradually monostratify into ON and OFF sublaminae. The

Light‐dependent plasticity of the synaptic terminals of Mb bipolar cells in goldfish retina

  • Stephen YazullaK. Studholme
  • Biology
    The Journal of comparative neurology
  • 1992
It is suggested that the increased frequency of spinules during dark adaptation is related to an enhancement of synaptic transmission from a minor amacrine cell input when the major input from GABAergic amACrine cells is reduced.

ON cone bipolar cells in rat express the metabotropic receptor mGluR6

It is demonstrated that mGluR6 is indeed expressed in the dendritic tips of cone bipolar cells, the majority of which receive a ribbon synapse, and thus probably are ON coneipolar cells, implying that all ON cone bipolar cell types express mGLUR6.