A negative slope in the current-voltage relationship of the Na+/K+ pump inXenopus oocytes produced by reduction of external [K+]

1991 ◽  
Vol 121 (2) ◽  
pp. 177-187 ◽  
Author(s):  
R. F. Rakowski ◽  
L. A. Vasilets ◽  
J. LaTona ◽  
W. Schwarz
Keyword(s):  
Negative Slope ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship ◽  
External K

scholarly journals Plasticity of calcium-permeable AMPA glutamate receptors in Pro-opiomelanocortin neurons

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Shigetomo Suyama ◽  
Alexandra Ralevski ◽  
Zhong-Wu Liu ◽  
Marcelo O Dietrich ◽  
Toshihiko Yada ◽  
...  
Keyword(s):  
Food Deprivation ◽  
High Fat Diet ◽  
Receptor Complex ◽  
High Fat ◽  
Fasted State ◽  
Linear Current ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship

POMC neurons integrate metabolic signals from the periphery. Here, we show in mice that food deprivation induces a linear current-voltage relationship of AMPAR-mediated excitatory postsynaptic currents (EPSCs) in POMC neurons. Inhibition of EPSCs by IEM-1460, an antagonist of calcium-permeable (Cp) AMPARs, diminished EPSC amplitude in the fed but not in the fasted state, suggesting entry of GluR2 subunits into the AMPA receptor complex during food deprivation. Accordingly, removal of extracellular calcium from ACSF decreased the amplitude of mEPSCs in the fed but not the fasted state. Ten days of high-fat diet exposure, which was accompanied by elevated leptin levels and increased POMC neuronal activity, resulted in increased expression of Cp-AMPARs on POMC neurons. Altogether, our results show that entry of calcium via Cp-AMPARs is inherent to activation of POMC neurons, which may underlie a vulnerability of these neurons to calcium overload while activated in a sustained manner during over-nutrition.

Capsaicin and nicotine both activate a subset of rat trigeminal ganglion neurons

1996 ◽  
Vol 270 (6) ◽  
pp. C1807-C1814 ◽  
Author(s):  
L. Liu ◽  
S. A. Simon
Keyword(s):  
Trigeminal Ganglion ◽  
Acetylcholine Receptors ◽  
Ganglion Cells ◽  
Whole Cell Patch Clamp ◽  
Current Voltage ◽  
Trigeminal Ganglion Neurons ◽  
Ganglion Neurons ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship

Nicotine and capsaicin produce many similar physiological responses that include pain, irritation, and vasodilation. To determine whether neuronal nicotine acetylcholine receptors (nAChR) are present on capsaicin-sensitive neurons, whole cell patch-clamp recordings were performed on rat trigeminal ganglion cells. It was found that approximately 20% of the total number of neurons tested was activated by both 100 microM nicotine and 1 nM capsaicin. Other subsets of neurons were activated by only one of these compounds, whereas a fourth subset was not activated by either compound. At -60 mV, the magnitude of the capsaicin-activated currents was about three times larger than the magnitude of the nicotine-activated currents. The current-voltage relationship of the nAChR exhibited marked rectification, such that for voltages > or = 0 mV the current was essentially zero. In contrast, the current-voltage relationship of the capsaicin-activated current was ohmic from +/- 60 mV. These data indicate the existence of subsets of capsaicin-sensitive afferent neurons.

Current-voltage relationship of the basolateral membrane of a tight epithelium

1979 ◽  
Vol 555 (3) ◽  
pp. 519-523 ◽  
Author(s):  
Nancy K. Wills ◽  
Douglas C. Eaton ◽  
Simon A. Lewis ◽  
Mark S. Ifshin
Keyword(s):  
Basolateral Membrane ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship ◽  
Tight Epithelium

On the current-voltage relationship of the magnetospheric generator at intermediate spatial scales

1986 ◽  
Vol 13 (6) ◽  
pp. 495-498 ◽  
Author(s):  
J. F. Vickrey ◽  
R. C. Livingston ◽  
N. B. Walker ◽  
T. A. Potemra ◽  
R. A. Heelis ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship

scholarly journals Contributions of space-clamp errors to apparent time-dependent loss of Mg2+ block induced by NMDA

2017 ◽  
Vol 118 (1) ◽  
pp. 532-543
Author(s):  
Min-Yu Sun ◽  
Mariangela Chisari ◽  
Lawrence N. Eisenman ◽  
Charles F. Zorumski ◽  
Steven J. Mennerick
Keyword(s):  
Voltage Clamp ◽  
Hippocampal Neurons ◽  
Network Activity ◽  
Negative Slope ◽  
Secondary Currents ◽  
Current Voltage ◽  
Nmda Current ◽  
Current Voltage Relationship ◽  
Voltage Relationship ◽  
Juvenile Mouse

N-methyl-d-aspartate receptors (NMDARs) govern synaptic plasticity, development, and neuronal response to insult. Prolonged activation of NMDARs such as during an insult may activate secondary currents or modulate Mg2+ sensitivity, but the conditions under which these occur are not fully defined. We reexamined the effect of prolonged NMDAR activation in juvenile mouse hippocampal slices. NMDA (10 μM) elicited current with the expected negative-slope conductance in the presence of 1.2 mM Mg2+. However, several minutes of continued NMDA exposure elicited additional inward current at −70 mV. A higher concentration of NMDA (100 µM) elicited the current more rapidly. The additional current was not dependent on Ca2+, network activity, or metabotropic NMDAR function and did not persist on agonist removal. Voltage ramps revealed no alteration of either reversal potential or NMDA-elicited conductance between −30 mV and +50 mV. The result was a more linear NMDA current-voltage relationship. The current linearization was also induced in interneurons and in mature dentate granule neurons but not immature dentate granule cells, dissociated cultured hippocampal neurons, or nucleated patches excised from CA1 pyramidal neurons. Comparative simulations of NMDA application to a CA1 pyramidal neuron and to a cultured neuron revealed that linearization can be explained by space-clamp errors arising from gradual recruitment of distal dendritic NMDARs. We conclude that persistent secondary currents do not strongly contribute to NMDAR responses in juvenile mouse hippocampus and careful discernment is needed to exclude contributions of clamp artifacts to apparent secondary currents. NEW & NOTEWORTHY We report that upon sustained activation of NMDARs in juvenile mouse hippocampal neurons there is apparent loss of Mg2+ block at negative membrane potentials. However, the phenomenon is explained by loss of dendritic voltage clamp, leading to a linear current-voltage relationship. Our results give a specific example of how spatial voltage errors in voltage-clamp recordings can readily be misinterpreted as biological modulation.

scholarly journals A simulation study of the current-voltage relationship of the Io tail aurora

2012 ◽  
Vol 117 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. Matsuda ◽  
N. Terada ◽  
Y. Katoh ◽  
H. Misawa
Keyword(s):  
Simulation Study ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship
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