Method
A classic sucrose gap technique is typically set up with three chambers that each contain a segment of the neuron or cells that are being studied. The test chamber contains a physiological solution, such as Krebs or Ringer's solution, which mimics the ion concentration and osmotic pressure of the cell's natural environment. Test drugs can also be added to this chamber to study the effect that they have on cellular function. Ag-AgCl or platinum wire electrodes are generally used for stimulating the cells in the test solution. The sucrose chamber (or gap) is the middle chamber that separates the two other chambers, or sections of the nerve fiber or cells. This chamber contains an isotonic sucrose solution of a high specific resistance. Specific resistance describes the ability of a material or solution to oppose electrical current, so a sucrose solution of a high specific resistance is effective in electrically isolating the three chambers. The third chamber usually contains a KCl solution that mimics the intracellular solution. The high potassium concentration in this chamber depolarizes the immersed segment of the tissue, allowing potential differences to be measured between the two segments separated by the sucrose gap. Vaseline, silicon grease, or a silicon-vaseline mixture is used to seal the nerve or tissue in position and prevent diffusion of solution between the chambers. A pair of agar-bridged Ag-AgCl electrodes are placed in the test and KCl chambers to record the changes in membrane potential.
Read more about this topic: Sucrose Gap
Famous quotes containing the word method:
“In child rearing it would unquestionably be easier if a child were to do something because we say so. The authoritarian method does expedite things, but it does not produce independent functioning. If a child has not mastered the underlying principles of human interactions and merely conforms out of coercion or conditioning, he has no tools to use, no resources to apply in the next situation that confronts him.”
—Elaine Heffner (20th century)
“Women are denied masturbation even more severely than men and that’s another method of control—they’re not taught to please themselves.... Most women—it takes them a while to warm up to the “situation” but once they get into it, I’m sure they’re going to get just as hooked as—well, everyone I know is!”
—Lydia Lunch (b. 1959)
“The good husband finds method as efficient in the packing of fire-wood in a shed, or in the harvesting of fruits in the cellar, as in Peninsular campaigns or the files of the Department of State.”
—Ralph Waldo Emerson (1803–1882)