BASIS OF BIOELECTRICITY
Wherever they look, biophysicists experimenting on plants and animals find biological batteries. Sometimes they study large collections of such cells--as in the brain, or in heart muscle--and sometimes they work with single cells, but whatever the biological preparation may be, a measurable electrical phenomenon turns up as it goes about its process of living. The efforts of generations of researchers show that the growing tip of an onion root and the secreting glands of a human stomach follow the same general rules. A single plant cell displays electrical properties remarkably similar to those of a single nerve or muscle cell of the frog. This chapter and the next take up some of the generalizations applying to normally acting nerve and muscle cells--generalizations stemming in large part from measurement of electrical events.
To begin at the beginning, consider the plight of the physiologist setting out to study electrical activity of tissues. He is like someone abandoned on a desert island with an unlabeled phonograph record and no record player. Those grooves on the record hold something fascinating to hear, maybe even beautiful, if only their