Identification of a G-protein in depolarizing rod bipolar cells

1993 ◽  
Vol 10 (3) ◽  
pp. 473-478 ◽  
Author(s):  
Noga Vardi ◽  
Diane F. Matesic ◽  
David R. Manning ◽  
Paul A. Liebman ◽  
Peter Sterling
Keyword(s):  
Synaptic Transmission ◽  
G Protein ◽  
Glutamate Receptor ◽  
Mammalian Species ◽  
Bipolar Cells ◽  
Protein G ◽  
Wide Range ◽  
Gated Channel ◽  
Phototransduction Cascade ◽  
Rod Bipolar Cells

AbstractSynaptic transmission from photoreceptors to depolarizing bipolar cells is mediated by the APB glutamate receptor. This receptor apparently is coupled to a G-protein which activates cGMP-phosphodiesterase to modulate cGMP levels and thus a cGMP-gated cation channel. We attempted to localize this system immunocytochemically using antibodies to various components of the rod phototransduction cascade, including Gt (transducin), phosphodiesterase, the cGMP-gated channel, and arrestin. All of these antibodies reacted strongly with rods, but none reacted with bipolar cells. Antibodies to a different G-protein, Go, reacted strongly with rod bipolar cells of three mammalian species (which are depolarizing and APB-sensitive). Also stained were subpopulations of cone bipolar cells but not the major depolarizing type in cat (b1). Go antibody also stained certain salamander bipolar cells. Thus, across a wide range of species, Go is present in retinal bipolar cells, and at least some of these are depolarizing and APB-sensitive.

Reciprocal inhibition of voltage-gated potassium currents (IK(V)) by activation of cannabinoid CB1and dopamine D1receptors in ON bipolar cells of goldfish retina

2005 ◽  
Vol 22 (1) ◽  
pp. 55-63 ◽  
Author(s):  
SHIH-FANG FAN ◽  
STEPHEN YAZULLA
Keyword(s):  
G Protein ◽  
Receptor Agonist ◽  
Lucifer Yellow ◽  
Reciprocal Inhibition ◽  
Receptor Activation ◽  
Light Signal ◽  
Bipolar Cells ◽  
Protein G ◽  
Calcium Dependent ◽  
Voltage Dependent

Cannabinoid CB1receptor (viaGs) and dopamine D2receptor (viaGi/o) antagonistically modulate goldfish cone membrane currents. As ON bipolar cells have CB1and D1receptors, but not D2receptors, we focused on whether CB1receptor agonist and dopamine interact to modulate voltage-dependent outward membrane K+currentsIK(V)of the ON mixed rod/cone (Mb) bipolar cells. Whole-cell currents were recorded from Mb bipolar cells in goldfish retinal slices. Mb bipolar cells were identified by intracellular filling with Lucifer yellow. The bath solution was calcium-free and contained 1 mM cobalt to block indirect calcium-dependent effects. Dopamine (10 μM) consistently increasedIK(V)by a factor of 1.57 ± 0.12 (S.E.M.,n= 15). A CB receptor agonist, WIN 55212-2 (0.25–1 μM), had no effect, but 4 μM WIN 55212-2 suppressedIK(V)by 60%. IfIK(V)was first increased by 10 μM dopamine, application of WIN 55212-2 (0.25–1 μM) reversibly blocked the effect of dopamine even though these concentrations of WIN 55212-2 had no effect of their own. If WIN 55212-2 was applied first and dopamine (10 μM) was added to the WIN-containing solution, 0.1 μM WIN 55212-2 blocked the effect of dopamine. All effects of WIN 55212-2 were blocked by coapplication of SR 141716A (CB1antagonist) and pretreatment with pertussis toxin (blocker of Gi/o) indicating actionviaCB1receptor activation of G protein Gi/o. Coactivation of CB1and D1receptors on Mb bipolar cells produces reciprocal effects onIK(V). The CB1-evoked suppression ofIK(V)is mediated by G protein Gi/o, whereas the D1-evoked enhancement is mediated by G protein Gs. As dopamine is a retinal “light” signal, these data support our notion that endocannabinoids function as a “dark” signal, interacting with dopamine to set retinal sensitivity.

scholarly journals Transducin translocation contributes to rod survival and enhances synaptic transmission from rods to rod bipolar cells

2013 ◽  
Vol 110 (30) ◽  
pp. 12468-12473 ◽  
Author(s):  
A. Majumder ◽  
J. Pahlberg ◽  
K. K. Boyd ◽  
V. Kerov ◽  
S. Kolandaivelu ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Bipolar Cells ◽  
Rod Bipolar Cells

Orexin-B modulates synaptic transmission of rod bipolar cells in rat retina

2018 ◽  
Vol 133 ◽  
pp. 38-50 ◽  
Author(s):  
Gong Zhang ◽  
Xiao-Hua Wu ◽  
Guo-Zhong Xu ◽  
Shi-Jun Weng ◽  
Xiong-Li Yang ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Bipolar Cells ◽  
Rat Retina ◽  
Rod Bipolar Cells

The effects of serotonin agonists and antagonists on the response properties of complex ganglion cells in the rabbit's retina

1988 ◽  
Vol 1 (2) ◽  
pp. 181-188 ◽  
Author(s):  
William J. Brunken ◽  
Nigel W. Daw
Keyword(s):  
Synaptic Transmission ◽  
Spontaneous Activity ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Orientation Selectivity ◽  
Bipolar Cells ◽  
Evoked Responses ◽  
Selective Agonists ◽  
Rod Bipolar Cells

AbstractSelective agonists and antagonists were employed to determine the role of indoleaminergic amacrine cells in the generation of the light-evoked responses and spontaneous activity of direction and orientation selective cells. Perfusion with 5-HT2 antagonists reduced the spontaneous activity and both the leading and trailing edge responses of ON/OFF direction selective cells. 5-HT1a agonists had a similar effect on this class of cell, namely, a reduction of light-evoked and spontaneous activity. Results from ON-center and OFF-center orientation selective cells were consistent with those obtained from direction selective cells in that no disruption of direction or orientation selectivity was observed during perfusion of these drugs. These data suggest that the indoleaminergic cells are not directly involved in the generation of the trigger features of complex ganglion cells, but may be facilitating synaptic transmission in the inner retina. This function is discussed relative to the connectivity of the rod bipolar cells and the putative indoleaminergic amacrine cells. The similarity of the effects of 5-HT1a agonists and 5-HT2 antagonists supports the hypothesis, developed during our prior studies of brisk ganglion cells, that these two receptor classes mediate antagonistic processes in the target neurons.

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