R-type Ca2+ channels contribute to fast synaptic excitation and action potentials in subsets of myenteric neurons in the guinea pig intestine

Naidoo, Vinogran; Dai, Xiaoling; Galligan, James J.

doi:10.1111/j.1365-2982.2010.01596.x

Cited by 11 publications

(12 citation statements)

References 32 publications

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“…These data also show expression of the α1E subunit in varicose nerve fibers in myenteric ganglia. This observation is consistent with our previous results showing that R-type Ca 2+ channels contribute to fast synaptic transmission in the myenteric plexus (Naidoo et al, 2010). These data all support a role for R-type Ca 2+ channels in synaptic and neuromuscular transmission in the guinea pig small intestine.…”

Section: Discussionsupporting

confidence: 94%

R‐Type Ca²⁺ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

Rodriguez‐Tapia

Naidoo

DeVries

et al. 2017

Experimental Physiology

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There is evidence that R-type Ca2+ channels contribute to synaptic transmission in the myenteric plexus. It is unknown if R-type Ca2+ channels contribute to neuromuscular transmission. We measured the effects of the nitric oxide synthase (NOS) inhibitor, nitro L-arginine (NLA), Ca2+ channel blockers and apamin (SK channel blocker) on neurogenic relaxations and contractions of the guinea pig ileum longitudinal muscle-myenteric plexus (LMMP) in vitro. We used intracellular recordings to measure inhibitory junction potentials (IJPs). Immunohistochemical and western blot techniques localized R-type Ca2+ channel protein in the LMMP and circular muscle. CdCl2 (pan Ca2+ channel blocker) blocked and NLA and NiCl2 (R-type Ca2+ channel blocker) reduced neurogenic relaxations in a non-additive manner. NiCl2 did not alter neurogenic cholinergic contractions but it potentiated neurogenic non-cholinergic contractions. Relaxations were inhibited by apamin, NiCl2 and NLA and were blocked by combined application of these drugs. Relaxations were reduced by NiCl2 or ω-conotoxin (ω-CTX, N-type Ca2+ channel blocker) and were blocked by combined application of these drugs. Longitudinal muscle IJPs were inhibited by NiCl2, but not MRS 2179 (P2Y1 receptor antagonist). Circular muscle IJPs were blocked by apamin, MRS 2179, ω-CTX and CdCl2 but not NiCl2. We conclude that neuronal R-type Ca2+ channels contribute to inhibitory neurotransmission to longitudinal muscle but less so or not all in the circular muscle of the guinea pig ileum.

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Section: Discussionsupporting

confidence: 94%

R‐Type Ca²⁺ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

Rodriguez‐Tapia

Naidoo

DeVries

et al. 2017

Experimental Physiology

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“…ω-Conotoxin GVIA is a blocker of N-type calcium channels that blocks electrically induced synaptic responses in the ENS when recorded with voltage sensitive dye imaging1722, Ca ++ imaging23 or intracellular electrodes (virtually abolished)24. We found no significant difference in the response to anti-HuD before and after ω-Conotoxin GVIA (spike frequency 3.4 ± 2.9 Hz vs. 2.6 ± 1.9 Hz, P = 0.162), suggesting a direct, postsynaptic effect of the antibodies (Fig.…”

Section: Resultsmentioning

confidence: 99%

Anti-Hu antibodies activate enteric and sensory neurons

Michel

Annaházi

et al. 2016

Sci Rep

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IgG of type 1 anti-neuronal nuclear antibody (ANNA-1, anti-Hu) specificity is a serological marker of paraneoplastic neurological autoimmunity (including enteric/autonomic) usually related to small-cell lung carcinoma. We show here that IgG isolated from such sera and also affinity-purified anti-HuD label enteric neurons and cause an immediate spike discharge in enteric and visceral sensory neurons. Both labelling and activation of enteric neurons was prevented by preincubation with the HuD antigen. Activation of enteric neurons was inhibited by the nicotinic receptor antagonists hexamethonium and dihydro-β-erythroidine and reduced by the P2X antagonist pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid (PPADS) but not by the 5-HT3 antagonist tropisetron or the N-type Ca-channel blocker ω-Conotoxin GVIA. Ca++ imaging experiments confirmed activation of enteric neurons but not enteric glia. These findings demonstrate a direct excitatory action of ANNA-1, in particular anti-HuD, on visceral sensory and enteric neurons, which involves nicotinic and P2X receptors. The results provide evidence for a novel link between nerve activation and symptom generation in patients with antibody-mediated gut dysfunction.

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“…Verapamil, however, can be rather poorly selective, especially at this concentration. The slow kinetics of the current suggested the possibility that the channel might be an R-like channel (Naidoo, 2010). R-like channels have been seen in neurons of Periplaneta americana .…”

Section: Glial Cell Electrophysiology During the Period Of Axon Ingrowthmentioning

confidence: 99%

“…R-like channels have been seen in neurons of Periplaneta americana . The agatoxin SNX-482, a highly specific blocker of R-type channels (Naidoo, 2010), was pipetted into the recording chamber to yield a final concentration of 0.1 μM, and the response of the cell to a standard family of voltage steps was followed at 1-, 5-and 10-min intervals. The calcium current had already decreased at 1 minute, was abolished by 10 minutes, and could be recovered with a 10-min wash in recording solution even after repeated applications of SNX-482 (Fig.…”

Section: Glial Cell Electrophysiology During the Period Of Axon Ingrowthmentioning

confidence: 99%

Development of a glial network in the olfactory nerve: role of calcium and neuronal activity

2010

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In adult olfactory nerves of mammals and moths, a network of glial cells ensheathes small bundles of olfactory receptor axons. In the developing antennal nerve (AN) of the moth Manduca sexta, the axons of olfactory receptor neurons (ORNs) migrate from the olfactory sensory epithelium toward the antennal lobe. Here we explore developmental interactions between ORN axons and AN glial cells. During early stages in AN glial-cell migration, glial cells are highly dye coupled, dividing glia are readily found in the nerve and AN glial cells label strongly for glutamine synthetase. By the end of this period, dye-coupling is rare, glial proliferation has ceased, glutamine synthetase labeling is absent, and glial processes have begun to extend to enwrap bundles of axons, a process that continues throughout the remainder of metamorphic development. Whole-cell and perforated-patch recordings in vivo from AN glia at different stages of network formation revealed two potassium currents and an R-like calcium current. Chronic in vivo exposure to the R-type channel blocker SNX-482 halted or greatly reduced AN glial migration. Chronically blocking spontaneous Na-dependent activity by injection of tetrodotoxin reduced the glial calcium current implicating an activity-dependent interaction between ORNs and glial cells in the development of glial calcium currents.

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R-type Ca2+ channels contribute to fast synaptic excitation and action potentials in subsets of myenteric neurons in the guinea pig intestine

Cited by 11 publications

References 32 publications

R‐Type Ca²⁺ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

R‐Type Ca²⁺ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

Anti-Hu antibodies activate enteric and sensory neurons

Development of a glial network in the olfactory nerve: role of calcium and neuronal activity

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R-type Ca2+ channels contribute to fast synaptic excitation and action potentials in subsets of myenteric neurons in the guinea pig intestine

Cited by 11 publications

References 32 publications

R‐Type Ca2+ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

R‐Type Ca2+ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

Anti-Hu antibodies activate enteric and sensory neurons

Development of a glial network in the olfactory nerve: role of calcium and neuronal activity

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Product

Resources

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R‐Type Ca²⁺ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum

R‐Type Ca²⁺ channels couple to inhibitory neurotransmission to the longitudinal muscle in the guinea‐pig ileum