Electrotonic structure and specific membrane properties of mouse dorsal root ganglion neurons.

Publisher Website
Google Scholar
Abstract
The passive membrane properties of cultured mouse dorsal root ganglion (DRG) neurons were studied electrophysiologically in defined salt solutions. In 12 of 14 cells, the experimental current-voltage curves could be fitted accurately by a simple electrotonic model consisting of an isopotential soma attached to a cylindrical process. In these cells, the average electrotonic length of the cylinder was 1.1 and the average value of .rho. was 1.6. Cultured DRG neurons are apparently electrically compact. The specific membrane resistance (Rm) and capacitance (Cm) were determined from the electrotonic structure combined with somatic area measurements. The average value of Rm was about 7000 .OMEGA. .cntdot. cm2 and the mean value of Cm was approximately 1 .mu.F/cm2. This value of Cm agrees with that of other carefully studied biological membranes. Discrepancies with earlier studies of sensory ganglion neurons are evaluated and are attributed to effects of electrotonic structure; this implies that Cm is nearly constant in a wide variety of cells.