Enhancement of low-voltage-activated calcium currents by group II metabotropic glutamate receptors in rat retinal ganglion cells

Robbins, Jon; Reynolds, A.Martyn; Treseder, Sarah A.; Davies, R. Gareth

doi:10.1016/s1044-7431(03)00056-3

Cited by 15 publications

(11 citation statements)

References 45 publications

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“…In vertebrates the phosphorylation of sodium channels by PKA leading to a reduction of inward sodium current was previously described (Catterall 2000;Li et al 1992;. Moreover, neurotransmitters such as dopamine also modulated voltage-gated sodium channels by cAMP/PKA pathway in neostriatal and hippocampal neurons (Cantrell et al 1997(Cantrell et al , 1999aSchiffmann et al 1995).…”

Section: Involvement Of Ptx-sensitive Gi/o Protein and Camp/pka Pathwmentioning

confidence: 89%

“…In addition, recent studies have also described a potent action of mGluR agonists on other voltage-gated calcium channels subtypes. These include low-voltage-activated calcium channels regulated by mGluR2 controlling activation of a protein tyrosine kinase in rat retinal ganglion cells (Robbins et al 2003) and P/Q-type channels inhibited by mGluR7a through a PKCdependent phosphorylation cascade in cultured cerebellar granule neurons (Perroy et al 2000). Although these voltagedependent ionic channels are known to have specialized functions in cellular excitability, only very few data are available about mGluR-induced regulation of the voltage-dependent sodium channel (Yang and Gereau 2004).…”

Section: Introductionmentioning

confidence: 99%

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Differential Regulation of Two Distinct Voltage-Dependent Sodium Currents by Group III Metabotropic Glutamate Receptor Activation in Insect Pacemaker Neurons

Lavialle-Defaix

Gautier²,

Defaix³

et al. 2006

Journal of Neurophysiology

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Using whole cell patch-clamp technique and immunocytochemistry on adult dorsal unpaired median (DUM) neurons isolated from the cockroach Periplaneta americana CNS, we reported the characterization of a native mGluR, sharing pharmacological properties with vertebrate metabotropic glutamate receptor III (mGluRIII) that regulated voltage-dependent sodium current (I(Na)). The global I(Na) was dissociated by means of l-glutamate sensitivity, deactivation time constant, voltage dependence of activation and inactivation, recovery from inactivation, and intracellular regulation process. These two currents were respectively designated I(Na1) and I(Na2) for l-glutamate-sensitive and -insensitive sodium currents. l-glutamate selectively reduced I(Na1) by an increase of intracellular cAMP level. Using different activators and/or inhibitors of G proteins and cAMP/PKA cascade, together with St-Ht31 (an inhibitor of PKA binding to AKAP) and AKAP-79 antibodies, we established that mGluRIII was linked to I(Na1) by a Gi/o and a suspected Gs protein. According to the activated signaling pathway, l-glutamate elevated the cAMP level, which thereby activated cytosolic PKA and released PKA bound to AKAP. As expected from both biophysical and pharmacological studies, we showed that, through an inhibition of I(Na1), l-glutamate increased DUM neuron spontaneous electrical activity. These results indicated that such mGluRIII-activated dual processes provided a new physiological control of pacemaker neuronal firing.

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Section: Involvement Of Ptx-sensitive Gi/o Protein and Camp/pka Pathwmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Differential Regulation of Two Distinct Voltage-Dependent Sodium Currents by Group III Metabotropic Glutamate Receptor Activation in Insect Pacemaker Neurons

Lavialle-Defaix

Gautier²,

Defaix³

et al. 2006

Journal of Neurophysiology

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“…Recently, it was described in rat retinal ganglion cells, that genistein prevented the enhancement of low voltage-activated calcium currents, which were induced by metabotropic glutamate receptor (mGluR) activation [23]. The authors believed that a protein tyrosine kinase step may be involved.…”

Section: Discussionmentioning

confidence: 99%

Effects of the protein tyrosine kinase inhibitor genistein and taurine on retinal function in isolated superfused retina

Lüke

Krott²,

Warga

et al. 2006

Graefe's Arch Clin Exp Ophthalmol

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“…RGCs were cultured as described by Robbins et al (2003). Retinas from P2-P20 Hooded Lister rats were subjected to digestion by papain and gentle trituration, and the cell suspension was centrifuged through a gradient mixture.…”

Section: Methodsmentioning

confidence: 99%

“…Mixed retinal cultures were plated onto poly-L-lysine-coated glass coverslips and maintained in modified DMEM-HBSS (Invitrogen) at 37°C and 5% CO 2 for 1-10 d before experimentation. RGCs were identified routinely from other cell types on the basis of soma diameter (Ͼ12 m), which was based on correlation with immunocytochemical staining (Thy1.1; Chemicon, Temecula, CA; FITC-IgC; Boehringer Mannheim, Mannheim, Germany) and patterns of electrical activity recorded using whole-cell current clamp (Lilley, 2001;Robbins et al, 2003).…”

Section: Methodsmentioning

confidence: 99%

The Discovery and Characterization of a Proton-Gated Sodium Current in Rat Retinal Ganglion Cells

Lilley¹,

Tissier²,

Robbins³

2004

J. Neurosci.

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The conduction of acid-evoked currents in central and sensory neurons is now primarily attributed to a family of proteins called acid-sensing ion channels (ASICs). In peripheral neurons, their physiological function has been linked to nociception, mechanoreception, and taste transduction; however, their role in the CNS remains unclear. This study describes the discovery of a proton-gated current in rat retinal ganglion cells termed I Na(Hϩ) , which also appears to be mediated by ASICs. RT-PCR confirmed the presence of ASIC mRNA (subunits la, 2a, 2b, 3, and 4) in the rat retina. Electrophysiological investigation showed that all retinal ganglion cells respond to rapid extracellular acidification with the activation of a transient Na ϩ current, the size of which increases with increasing acidification between pH 6.5 and pH 3.0. I Na(Hϩ) desensitizes completely in the continued presence of acid, its current-voltage relationship is linear and its reversal potential shifts with E Na . I Na(Hϩ) is reversibly inhibited by amiloride (IC 50 , 188 M) but is resistant to block by TTX (0.5 M), Cd 2ϩ (100 M), procaine (10 mM), and is not activated by capsaicin (0.5 M). I Na(Hϩ) is not potentiated by Zn 2ϩ (300 M) or Phe-MetArg-Phe-amide (50 M) but is inhibited by neuropeptide-FF (50 M). Acute application of pH 6.5 to retinal ganglion cells causes sustained depolarization and repetitive firing similar to the trains of action potentials normally associated with current injection into these cells. The presence of a proton-gated current in the neural retina suggests that ASICs may have a more diverse role in the CNS.

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Enhancement of low-voltage-activated calcium currents by group II metabotropic glutamate receptors in rat retinal ganglion cells

Cited by 15 publications

References 45 publications

Differential Regulation of Two Distinct Voltage-Dependent Sodium Currents by Group III Metabotropic Glutamate Receptor Activation in Insect Pacemaker Neurons

Differential Regulation of Two Distinct Voltage-Dependent Sodium Currents by Group III Metabotropic Glutamate Receptor Activation in Insect Pacemaker Neurons

Effects of the protein tyrosine kinase inhibitor genistein and taurine on retinal function in isolated superfused retina

The Discovery and Characterization of a Proton-Gated Sodium Current in Rat Retinal Ganglion Cells

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