scholarly journals Characterization of L-type voltage-gated Ca2+ channel expression and function in developing CA3 pyramidal neurons

Neuroscience ◽  
2013 ◽  
Vol 238 ◽  
pp. 59-70 ◽  
Author(s):  
R.A. Morton ◽  
M.S. Norlin ◽  
C.C. Vollmer ◽  
C.F. Valenzuela
Keyword(s):  
Pyramidal Neurons ◽  
Voltage Gated ◽  
Channel Expression ◽  
Ca3 Pyramidal Neurons ◽  
And Function

Analysis of voltage-gated and synaptic conductances contributing to network excitability defects in the mutant mouse tottering

1994 ◽  
Vol 71 (1) ◽  
pp. 1-10 ◽  
Author(s):  
S. A. Helekar ◽  
J. L. Noebels
Keyword(s):  
Gabaa Receptor ◽  
Pyramidal Neurons ◽  
Hippocampal Slices ◽  
Channel Blockers ◽  
Gamma Aminobutyric Acid ◽  
Voltage Gated ◽  
Voltage Dependent ◽  
Prolonged Duration ◽  
Ca3 Pyramidal Neurons ◽  
The Difference

1. Intracellular current- and voltage-clamp recordings were carried out in CA3 pyramidal neurons from hippocampal slices of adult tg/tg mice and their coisogenic C57BL/6J (+/+) controls with the use of the single-electrode switch-clamp technique. The principal aim of this study was to investigate the mechanisms responsible for the tg gene-linked prolongation (mean 60%) of a giant synaptic response, the potassium-induced paroxysmal depolarizing shift (PDS) at depolarized membrane potentials (Vm -47 to -54 mV) during synchronous network bursting induced by 10 mM potassium ([K+]o). 2. To examine the role of intrinsic voltage-dependent conductances underlying the mutant PDS prolongation, neurons were voltage clamped by the use of microelectrodes filled with 100 mM QX-314 or QX-222 chloride (voltage-gated sodium channel blockers) and 2 M cesium sulphate (potassium channel blocker). The whole-cell currents active during the PDS showed a significantly prolonged duration (mean 34%) at depolarized Vms in tg/tg compared with +/+ cells, indicating that a defect in voltage-dependent conductances is unlikely to completely account for the mutant phenotype. 3. Bath application of 40 microM (DL)-2-aminophosphonovalerate (DL-APV) produced a 30% reduction in PDS duration in both genotypes but failed to significantly alter the tg gene-linked prolongation compared with the wild type. These data indicate that the mutant PDS abnormality does not result from a selective increase of the N-methyl-D-aspartate (NMDA) receptor-mediated excitatory synaptic component. 4. Blockade of gamma-aminobutyric acid-A (GABAA) transmission with picrotoxin (50 microM) or bicuculline (1–5 microM) completely eliminated the difference in PDS duration between the genotypes. Furthermore, although both GABAA receptor antagonists increased the mean PDS duration in +/+ neurons, they did not significantly alter it in tg/tg neurons. These findings are consistent with a reduction in GABAA receptor-mediated synaptic inhibition during bursting in the tg CA3 hippocampal network. 5. To test this hypothesis, bursting CA3 pyramidal neurons were loaded intracellularly with chloride by the use of KCl-filled microelectrodes to examine the effect of reversing the hyperpolarizing chloride-dependent GABAA receptor-mediated inhibitory postsynaptic component of the PDS. Chloride loading prolonged PDS duration in both genotypes, but the increase was greater in +/+ than in tg/tg neurons, indicating that a smaller GABAA inhibitory postsynaptic potential (IPSP) component was reversed in the mutant.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract 17384: Cardiac-Specific Overexpression of Human Mutant Desmoplakin in Mice Disrupts Cardiac Voltage-Gated Sodium Channel Expression

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Subat Turdi ◽  
Jeffrey A Towbin
Keyword(s):  
Sodium Channel ◽  
Fatty Infiltration ◽  
Electrical Coupling ◽  
Cx43 Expression ◽  
Voltage Gated Sodium Channel ◽  
Voltage Gated ◽  
Intercalated Discs ◽  
Channel Expression ◽  
Life Threatening ◽  
And Function

Introduction: Arrhythmogenic cardiomyopathy (AC) is characterized by bi-ventricular dilation, fibro-fatty infiltration and life-threatening arrhythmias. Disruptions in cardiac voltage-gated sodium channel (Nav1.5) expression and function are known to cause arrhythmias. We have demonstrated that cardiac-specific overexpression of human mutant desmoplakin (DSP, Tg-R2834H) in mice leads to AC. However, whether mutant DSP expression in the heart affects the Nav1.5 distribution and function are unknown Hypothesis: Here, we tested whether Nav1.5 localization and expression are altered in the R2834H-Tg mouse hearts. Methods: Primary cardiomyocytes and frozen myocardial sections from non-transgenic (NTg), wild-type DSP (Tg-DSP) and Tg-R2834H mice were used for immunofluorescence studies to assess subcellular localization of DSP, desmin, Nav1.5, Cx43, plakoglobin and β-catenin. Western blot and qPCR were used for quantitative analysis. Results: Double staining of cardiomyocytes from NTg mice with DSP and Nav1.5 revealed that Nav1.5 was colocalized with DSP at the intercalated discs (IDs). In contrast, Tg-R2834H cardiomyocytes exhibited marked increase of mutant DSP expression at the IDs concomitant with a reduction in Nav1.5 immunoreactive signals. Tg-R2834H cardiomyocytes also revealed an aberration of DSP and desmin colocalizations at the IDs. There were not obvious differences in Cx43 expression between the genotypes, although the redistribution of Cx43 from the IDs to the sarcolemma was evident in Tg-R2834H cardiomyocytes. qPCR results correlated with reduced Nav1.5 mRNA expression in the Tg-R2834H mouse hearts. Conclusions: Defective DSP protein expression in the heart disrupts Nav1.5 localization and expression, implying an interaction between DSP and Nav1.5 to orchestrate normal mechanical and electrical coupling. Further electrophysiology studies to assess whole-cell Na + currents in these cardiomyocytes will provide insight into DSP and Nav1.5 interaction.

scholarly journals Development and Characterization of Monoclonal Antibodies Specific to the Serotonin 5-HT2A Receptor

1998 ◽  
Vol 46 (7) ◽  
pp. 811-824 ◽  
Author(s):  
Chun Wu ◽  
Elizabeth J. Yoder ◽  
Jean Shih ◽  
Kevin Chen ◽  
Peter Dias ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Rat Brain ◽  
Pyramidal Neurons ◽  
Expression System ◽  
Molecular Size ◽  
Baculovirus Expression System ◽  
Differential Staining ◽  
Receptor Subtypes ◽  
And Function

Serotonin (5-hydroxytryptamine, 5-HT) mediates many functions of the central and peripheral nervous systems by its interaction with specific neuronal and glial receptors. Fourteen serotonin receptors belonging to seven families have been identified through physiological, pharmacological, and molecular cloning studies. Monoclonal antibodies (MAbs) specific for each of these receptor subtypes are needed to characterize their expression, distribution, and function in embryonic, adult, and pathological tissues. In this article we report the development and characterization of MAbs specific to the serotonin 5-HT2A receptor. To generate MAbs against 5-HT2AR, mice were immunized with the N-terminal domain of the receptor. The antigens were produced as glutathionine S-transferase (GST) fusion proteins in insect cells using a Baculovirus expression system. The hybridomas were initially screened by ELISA against the GST-5-HT2AR recombinant proteins and subsequently against GST control proteins to eliminate clones with unwanted reactivity. They were further tested by Western blotting against recombinant GST-5-HT2AR, rat and human brain lysate, and lysate from cell lines transfected with 5-HT2AR cDNA. One of the MAbs G186-1117, which recognizes a portion of the 5-HT2AR N-terminus, was selected for further characterization. G186-1117 reacted with a band of molecular size 55 kD corresponding to the predicted size of 5-HT2AR in lysates from rat brain and a 5-HT2AR-transfected cell line. Its specificity was further confirmed by adsorption of immunoreactivity with recombinant 5-HT2AR but not with recombinant 5-HT2BR and 5-HT2CR. Rat brain sections and Schwann cell cultures were immunohistochemically labeled with this MAb. G186-1117 showed differential staining in various regions of the rat brain, varying from regions with no staining to regions of intense reactivity. In particular, staining of cell bodies and dendrites of the pyramidal neurons in the cortex was observed, which is in agreement with observations of electrophysiological studies.

scholarly journals Voltage Gated Proton Channel Expression and Function in Breast Cancer Cells

2017 ◽  
Vol 112 (3) ◽  
pp. 333a
Author(s):  
Dan Bare ◽  
Vladimir V. Cherny ◽  
Abde M. Abukhdeir ◽  
Thomas E. DeCoursey ◽  
Deri Morgan
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Proton Channel ◽  
Voltage Gated ◽  
Channel Expression ◽  
And Function

scholarly journals Voltage-gated sodium channel expression and function in injured and uninjured sensory ganglia neurons

2012 ◽  
Vol 13 (4) ◽  
pp. S41
Author(s):  
B. Moyer ◽  
R. Yin ◽  
D. Liu ◽  
M. Chhoa ◽  
C. Li ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Sensory Ganglia ◽  
Voltage Gated Sodium Channel ◽  
Voltage Gated ◽  
Channel Expression ◽  
And Function

scholarly journals Calcium and Potassium Channels in Experimental Subarachnoid Hemorrhage and Transient Global Ischemia

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Marcel A. Kamp ◽  
Maxine Dibué ◽  
Toni Schneider ◽  
Hans-Jakob Steiger ◽  
Daniel Hänggi
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Animal Models ◽  
Ion Channel ◽  
Potassium Channel ◽  
Global Ischemia ◽  
Voltage Gated ◽  
Delayed Cerebral Vasospasm ◽  
Channel Expression ◽  
Transient Global Ischemia ◽  
And Function

Healthy cerebrovascular myocytes express members of several different ion channel families which regulate resting membrane potential, vascular diameter, and vascular tone and are involved in cerebral autoregulation. In animal models, in response to subarachnoid blood, a dynamic transition of ion channel expression and function is initiated, with acute and long-term effects differing from each other. Initial hypoperfusion after exposure of cerebral vessels to oxyhemoglobin correlates with a suppression of voltage-gated potassium channel activity, whereas delayed cerebral vasospasm involves changes in other potassium channel and voltage-gated calcium channels expression and function. Furthermore, expression patterns and function of ion channels appear to differ between main and small peripheral vessels, which may be key in understanding mechanisms behind subarachnoid hemorrhage-induced vasospasm. Here, changes in calcium and potassium channel expression and function in animal models of subarachnoid hemorrhage and transient global ischemia are systematically reviewed and their clinical significance discussed.

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