scholarly journals GABAB receptors enhance excitatory responses in isolated rat retinal ganglion cells

2016 ◽  
Vol 594 (19) ◽  
pp. 5543-5554 ◽  
Author(s):  
Jay Garaycochea ◽  
Malcolm M. Slaughter
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Gabab Receptors ◽  
Retinal Ganglion ◽  
Excitatory Responses ◽  
Isolated Rat

scholarly journals Two Metabotropic γ-Aminobutyric Acid Receptors Differentially Modulate Calcium Currents in Retinal Ganglion Cells

1997 ◽  
Vol 110 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Jian Zhang ◽  
Wen Shen ◽  
Malcolm M. Slaughter
Keyword(s):  
Retinal Ganglion Cells ◽  
Gaba Receptors ◽  
Gaba Receptor ◽  
Ganglion Cells ◽  
Calcium Currents ◽  
Gabab Receptors ◽  
Aminobutyric Acid ◽  
Retinal Ganglion ◽  
Wide Range ◽  
Prepulse Facilitation

Metabotropic γ-aminobutyric acid (GABA) receptors were studied in amphibian retinal ganglion cells using whole cell current and voltage clamp techniques. The aim was to identify the types of receptor present and their mechanisms of action and modulation. Previous results indicated that ganglion cells possess two ionotropic GABA receptors: GABAAR and GABACR. This study demonstrates that they also possess two types of metabotropic GABAB receptor: one sensitive to baclofen and another to cis-aminocrotonic acid (CACA). The effects of these selective agonists were blocked by GDP-β-S. Baclofen suppressed an ω-conotoxin–GVIA-sensitive barium current, and this action was reversed by prepulse facilitation, indicative of a direct G-protein pathway. The effect of baclofen was also partially occluded by agents that influence the protein kinase A (PKA) pathway. But the effect of PKA activation was unaffected by prepulse facilitation, indicating PKA acted through a parallel pathway. Calmodulin antagonists reduced the action of baclofen, whereas inhibitors of calmodulin phosphatase enhanced it. Antagonists of internal calcium release, such as heparin and ruthenium red, did not affect the baclofen response. Thus, the baclofen-sensitive receptor may respond to influx of calcium. The CACA-sensitive GABA receptor reduced current through dihydropyridine-sensitive channels. Sodium nitroprusside and 8-bromo-cGMP enhanced the action of CACA, indicating that a nitric oxide system can up-regulate this receptor pathway. CACA-sensitive and baclofen-sensitive GABAB receptors reduced spike activity in ganglion cells. Overall, retinal ganglion cells possess four types of GABA receptor, two ionotropic and two metabotropic. Each has a unique electrogenic profile, providing a wide range of neural integration at the final stage of retinal information processing.

Calcium Signals Induced By Tonic Firing In Rat Retinal Ganglion Cells

2012 ◽  
Vol 3 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Kyril I. Kuznetsov ◽  
Vitaliy Yu. Maslov ◽  
Svetlana A. Fedulova ◽  
Nikolai S. Veselovsky
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Calcium Signals ◽  
Tonic Firing
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