[Study of the surface properties of spinal ganglion neurons in the rat by the microelectrophoresis technic].

Surface charges of isolated neurons of rat dorsal root ganglion were studied by the microelectrophoresis. It was shown that the surface potential of these neurons is produced by anion groups which form complexes with calcium ions and a binding constant ranging from 10 to 50 1/mole; they can be titrated by hydrogen ions according to pK = 3.8. Under trypsin treatment the surface loses most of these groups. Tosylchloride (reagent for aminogroups ) slightly increases the surface charge and N- bromsuccinimide (reagent for carboxylic groups) partially neutralizes it. It is suggested that the surface charge of rat dorsal root ganglion neurons measured by the microelectrophoresis is mainly determined by carboxylic groups of periphery proteins. These groups seem to be located in the glycoprotein sheath which covers the outer surface of the membrane. According to our estimates the average distance between these groups is about 2 nm and the thickness of the sheath is about 10 nm.