Sucrose space is about

The sucrose gap technique is used to create a conduction block in nerve or muscle fibers. A high concentration of sucrose is applied to the extracellular space, which prevents the correct opening and closing of sodium and potassium channels, increasing resistance between two groups of cells. It was originally developed by Robe Stampfli for recording action potentials in nerve fibers, and is paicularly useful for measuring irreversible or highly variable pharmacological modifications of channel propeies since untreated regions of membrane can be pulled into the node between the sucrose regions Ref: guyton and hall textbook of medical physiology 12 edition page number:475,476,477