Gramicidin Perforated Patch

2010 ◽  
pp. 141-147
Author(s):  
Norio Akaike
Keyword(s):  
Perforated Patch

Vasopressin Increases GABAergic Inhibition of Rat Hypothalamic Paraventricular Nucleus Neurons In Vitro

2000 ◽  
Vol 83 (2) ◽  
pp. 705-711 ◽  
Author(s):  
M.L.H.J. Hermes ◽  
J. M. Ruijter ◽  
A. Klop ◽  
R. M. Buijs ◽  
L. P. Renaud
Keyword(s):  
Paraventricular Nucleus ◽  
Receptor Agonist ◽  
Hypothalamic Paraventricular Nucleus ◽  
Membrane Properties ◽  
Magnocellular Neurons ◽  
Membrane Hyperpolarization ◽  
Perforated Patch ◽  
Intrinsic Membrane Properties ◽  
Brain Slice Preparation

This investigation used an in vitro hypothalamic brain slice preparation and whole cell and perforated-patch recording to examine the response of magnocellular neurons in hypothalamic paraventricular nucleus (PVN) to bath applications of vasopressin (VP; 100–500 nM). In 22/38 cells, responses were characterized by an increase in the frequency of bicuculline-sensitive inhibitory postsynaptic potentials or currents with no detectable influence on excitatory postsynaptic events. Perforated-patch recordings confirmed that VP did not have an effect on intrinsic membrane properties of magnocellular PVN neurons ( n = 17). Analysis of intrinsic membrane properties obtained with perforated-patch recording ( n = 23) demonstrated that all of nine VP-sensitive neurons showed a rebound depolarization after transient membrane hyperpolarization from rest. By contrast, 12/14 nonresponding neurons displayed a delayed return to resting membrane potentials. Recordings of reversed inhibitory postsynaptic currents with chloride-loaded electrodes showed that responses to VP persisted in media containing glutamate receptor antagonists but were abolished in the presence of tetrodotoxin. In addition, responses were mimicked by vasotocin [Phe2, Orn8], a selective V1a receptor agonist, and blocked by [β-Mercapto-β,β-cyclopentamethylenepropionyl1,O-Me-Tyr2, Arg8]-VP (Manning compound), a V1a/OT receptor antagonist. Neither [deamino-Cys1,Val4,d-Arg8]-VP, a selective V2 receptor agonist, nor oxytocin were effective. Collectively, the results imply that VP acts at V1a receptors to excite GABAergic neurons that are presynaptic to a population of magnocellular PVN neurons the identity of which features a unique rebound depolarization. Endogenous sources of VP may be VP-synthesizing neurons in suprachiasmatic nucleus, known to project toward the perinuclear regions of PVN, and/or the magnocellular neurons within PVN.

scholarly journals Excitatory GABA Responses in Embryonic and Neonatal Cortical Slices Demonstrated by Gramicidin Perforated-Patch Recordings and Calcium Imaging

1996 ◽  
Vol 16 (20) ◽  
pp. 6414-6423 ◽  
Author(s):  
David F. Owens ◽  
Leslie H. Boyce ◽  
Marion B. E. Davis ◽  
Arnold R. Kriegstein
Keyword(s):  
Calcium Imaging ◽  
Perforated Patch ◽  
Excitatory Gaba ◽  
Cortical Slices

scholarly journals Membrane responses to norepinephrine in cultured brown fat cells.

1990 ◽  
Vol 95 (3) ◽  
pp. 523-544 ◽  
Author(s):  
M T Lucero ◽  
P A Pappone
Keyword(s):  
Brown Fat ◽  
Fat Cells ◽  
Adrenergic Agonists ◽  
Whole Cell ◽  
K Channels ◽  
Inward Current ◽  
General Physiology ◽  
Perforated Patch ◽  
Beta Adrenergic Agonists ◽  
Outward Currents

We used the "perforated-patch" technique (Horn, R., and A. Marty, 1988. Journal of General Physiology. 92:145-159) to examine the effects of adrenergic agonists on the membrane potentials and membrane currents in isolated cultured brown fat cells from neonatal rats. In contrast to our previous results using traditional whole-cell patch clamp, 1-23-d cultured brown fat cells clamped with the perforated patch consistently showed vigorous membrane responses to both alpha- and beta-adrenergic agonists, suggesting that cytoplasmic components essential for the thermogenic response are lost in whole-cell experiments. The membrane responses to adrenergic stimulation varied from cell to cell but were consistent for a given cell. Responses to bath-applied norepinephrine in voltage-clamped cells had three possible components: (a) a fast transient inward current, (b) a slower outward current carried by K+ that often oscillated in amplitude, and (c) a sustained inward current largely by Na+. The fast inward and outward currents were activated by alpha-adrenergic agonists while the slow inward current was mediated by beta-adrenergic agonists. Oscillating outward currents were the most frequently seen response to norepinephrine stimulation. Activation of this current, termed IK,NE, was independent of voltage and seemed to be carried by Ca2(+)-activated K channels since the current oscillated in amplitude at constant membrane potential and gradually decreased when the cells were bathed with calcium-free external solution. IK,NE had a novel pharmacology in that it could be blocked by 4-aminopyridine, tetraethylammonium, apamin, and charybdotoxin. Both IK,NE and the voltage-gated K channels also present in brown fat (Lucero, M. T., and P. A. Pappone, 1989a. Journal of General Physiology. 93:451-472) may play a role in maintaining cellular homeostasis in the face of the high metabolic activity involved in thermogenesis.

Protein kinase inhibitor H-89 reverses forskolin stimulation of cardiac L-type calcium current

1995 ◽  
Vol 268 (3) ◽  
pp. C651-C659 ◽  
Author(s):  
W. Yuan ◽  
D. M. Bers
Keyword(s):  
Protein Kinase ◽  
Patch Clamp ◽  
Kinase Inhibitor ◽  
Ventricular Myocytes ◽  
Calcium Currents ◽  
Maximal Conductance ◽  
Perforated Patch ◽  
Dependent Inactivation ◽  
Protein Kinase N ◽  
Steady State Inactivation

Calcium currents (ICa) and barium currents (IBa) were measured in freshly isolated single ferret ventricular myocytes, using the whole cell patch-clamp and perforated patch-clamp techniques with Na and K currents blocked by tetraethylammonium and Cs. The membrane potential (Em) dependence of activation and steady-state inactivation curves were determined using a Boltzmann relation, where E0.5 is the Em at half-maximal conductance. Forskolin (1 microM) increased the rate of ICa inactivation, especially in perforated patch, but slowed IBa inactivation. The acceleration is likely to be due to greater Ca-dependent inactivation of ICa, where the slowing of IBa inactivation may be due to protein kinase A-dependent slowing of Em-dependent inactivation. Forskolin (1-10 microM) also increased ICa amplitude by two- to threefold and shifted the E0.5 for both activation and inactivation to more negative potentials by 7-8 mV. The effect of forskolin on the amplitude of ICa could be reversed by an inhibitor of adenosine 3',5'-cyclic monophosphate-dependent protein kinase, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89; 1-10 microM). However, H-89 did not reverse the shift of E0.5 induced by forskolin. H-89 application by itself does not decrease basal ICa but does shift the E0.5 of both activation and inactivation to more negative values of Em. It is possible that H-89 reverses the shift induced by regulatory phosphorylation (due to forskolin) but induces a coincidental negative shift itself.

Membrane Potential of CA3 Hippocampal Pyramidal Cells During Postnatal Development

2003 ◽  
Vol 90 (5) ◽  
pp. 2964-2972 ◽  
Author(s):  
Roman Tyzio ◽  
Anton Ivanov ◽  
Cristophe Bernard ◽  
Gregory L. Holmes ◽  
Yehezkiel Ben-Ari ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Postnatal Development ◽  
Developmental Change ◽  
Hippocampal Slices ◽  
Pyramidal Cells ◽  
Input Resistance ◽  
Whole Cell ◽  
Perforated Patch ◽  
Ca3 Pyramidal Cells ◽  
Whole Cell Recordings

A depolarized resting membrane potential has long been considered to be a universal feature of immature neurons. Despite the physiological importance, the underlying mechanisms of this developmental phenomenon are poorly understood. Using perforated-patch, whole cell, and cell-attached recordings, we measured the membrane potential in CA3 pyramidal cells in hippocampal slices from postnatal rats. With gramicidin perforated-patch recordings, membrane potential was –44 ± 4 (SE) mV at postnatal days P0–P2, and it progressively shifted to –67 ± 2 mV at P13–15. A similar developmental change of the membrane potential has been also observed with conventional whole cell recordings. However, the value of the membrane potential deduced from the reversal potential of N-methyl-d-aspartate channels in cell-attached recordings did not change with age and was –77 ± 2 mV at P2 and –77 ± 2 mV at P13–14. The membrane potential measured using whole cell recordings correlated with seal and input resistance, being most depolarized in neurons with high, several gigaohms, input resistance and low seal resistance. Simulations revealed that depolarized values of the membrane potential in whole cell and perforated-patch recordings could be explained by a shunt through the seal contact between the pipette and membrane. Thus the membrane potential of CA3 pyramidal cells appears to be strongly negative at birth and does not change during postnatal development.

Analysis of Single Neurons by Perforated Patch Clamp Recordings and MALDI-TOF Mass Spectrometry

2018 ◽  
Vol 9 (8) ◽  
pp. 2089-2096 ◽  
Author(s):  
Susanne Neupert ◽  
Debora Fusca ◽  
Peter Kloppenburg ◽  
Reinhard Predel
Keyword(s):  
Mass Spectrometry ◽  
Patch Clamp ◽  
Single Neurons ◽  
Perforated Patch ◽  
Maldi Tof Mass Spectrometry ◽  
Maldi Tof ◽  
Perforated Patch Clamp

Stimulation of Ca2+ current by phorbol esters in rat myometrial cells is dependent on intracellular Ca2+ concentration

1996 ◽  
Vol 8 (8) ◽  
pp. 1147 ◽  
Author(s):  
M Kusaka ◽  
N Sperelakis
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Voltage Clamp ◽  
Phorbol Esters ◽  
Cell Voltage ◽  
Muscle Cells ◽  
Whole Cell ◽  
Perforated Patch ◽  
Kinase C ◽  
Whole Cell Voltage Clamp

The effects of phorbol esters on the L-type Ca2+ current (ICa(L)) were investigated using nystatin-perforated patch and standard whole-cell voltage clamp in uterine smooth muscle cells isolated from late-pregnant rats. Using nystatin-perforated patch to maintain the integrity of the cytosol components, phorbol 12-myristate 13-acetate (PMA, 300 nM) increased ICa(L). When the standard whole-cell voltage clamp was used, the effect of PMA was dependent on the Ca2+ concentration in the pipette solution: PMA enhanced ICa(L) at pCa 6 and pCa 7 but not at pCa 10 or pCa 8. The effect of PMA was reversed by a selective inhibitor of protein kinase C, calphostin-C (500 nM). It is concluded that phorbol esters stimulate ICa(L) in uterine muscle cells and that the isoform of protein kinase C involved in this effect is Ca2+ dependent. This mechanism may be involved in the regulation of uterine contraction during pregnancy.

Sign in / Sign up

Export Citation Format

Share Document