Voltage Clamp and Internal Perfusion With Suction-Pipette Method

1985 ◽  
pp. 151-169 ◽  
Author(s):  
Arthur M. Brown ◽  
David L. Wilson ◽  
Yasuo Tsuda
Keyword(s):  
Voltage Clamp ◽  
Internal Perfusion

scholarly journals Properties of internally perfused, voltage-clamped, isolated nerve cell bodies.

1978 ◽  
Vol 71 (5) ◽  
pp. 489-507 ◽  
Author(s):  
K S Lee ◽  
N Akaike ◽  
A M Brown
Keyword(s):  
Voltage Clamp ◽  
Nerve Cell ◽  
Action Potentials ◽  
Divalent Cations ◽  
Membrane Resistance ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
Internal Perfusion ◽  
Shunt Resistance ◽  
Membrane Function

The membrane properties of isolated neurons from Helix aspersa were examined by using a new suction pipette method. The method combines internal perfusion with voltage clamp of nerve cell bodies separated from their axons. Pretreatment with enzymes such as trypsin that alter membrane function is not required. A platinized platinum wire which ruptures the soma membrane allows low resistance access directly to the cell's interior improving the time resolution under voltage clamp by two orders of magnitude. The shunt resistance of the suction pipette was 10-50 times the neuronal membrane resistance, and the series resistance of the system, which was largely due to the tip diameter, was about 10(5) omega. However, the peak clamp currents were only about 20 nA for a 60-mV voltage step so that measurements of membrane voltage were accurate to within at least 3%. Spatial control of voltage was achieved only after somal separation, and nerve cell bodies isolated in this way do not generate all-or-none action potentials. Measurements of membrane potential, membrane resistance, and membrane time constant are equivalent to those obtained using intracellular micropipettes, the customary method. With the axon attached, comparable all-or-none action potentials were also measured by either method. Complete exchange of Cs+ for K+ was accomplished by internal perfusion and allowed K+ currents to be blocked. Na+ currents could then be blocked by TTX or suppressed by Tris-substituted snail Ringer solution. Ca2+ currents could be blocked using Ni2+ and other divalent cations as well as organic Ca2+ blockers. The most favorable intracellular anion was aspartate-, and the sequence of favorability was inverted from that found in squid axon.

scholarly journals Hydrogen ion block of the sodium pore in squid giant axons.

1983 ◽  
Vol 82 (5) ◽  
pp. 599-618 ◽  
Author(s):  
T Begenisich ◽  
M Danko
Keyword(s):  
Binding Site ◽  
Voltage Clamp ◽  
Sodium Channels ◽  
Voltage Dependence ◽  
Hydrogen Ion ◽  
Hydrogen Ions ◽  
Internal Perfusion ◽  
Squid Axon ◽  
Giant Axons

The block of squid axon sodium channels by H ions was studied using voltage-clamp and internal perfusion techniques. An increase in the concentration of internal permeant ions decreased the block produced by external H ions. The voltage dependence of the block was found to be nonmonotonic: it was reduced by both large positive and large negative potentials. The ability of internal ions to modify the block by external H+ is explained by a competition among these ions for a binding site within the pore. The nonmonotonic voltage dependence is consistent with this picture if the hydrogen ions are allowed to be permeant.

scholarly journals Voltage clamp and internal perfusion of single rat heart muscle cells.

1981 ◽  
Vol 318 (1) ◽  
pp. 455-477 ◽  
Author(s):  
A M Brown ◽  
K S Lee ◽  
T Powell
Keyword(s):  
Voltage Clamp ◽  
Heart Muscle ◽  
Rat Heart ◽  
Muscle Cells ◽  
Internal Perfusion ◽  
Heart Muscle Cells
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