Abstract
Intracellular measurements were made on immature cultured rat neurons using single or double barrelled microelectrodes; 361 dorsal root ganglion, DRG, cells, 105 spinal cord cells and 12 cerebellar cells were studied. Membrane potentials recorded were in the range β25 mV to β50 mV. A statistically significant increase in membrane potentials with time in culture was found for DRG cells during 32 days in culture. This was not found for spinal cord cells.
Voltageβcurrent curves showed a nonβlinearity in about 50% of DRG and spinal cord cells similar to anomalous rectification. Measurements made in DRG and spinal cord cells at Β± 10 nA showed significantly greater average cell input resistance during hyperpolarising pulses than during depolarising pulses.
The calculated values of Rm and Cm for DRG and spinal cord cells were similar in magnitude to values given for other cells by other workers. The value for L, the dimensionless electrotonic length, was slightly higher than that calculated for motoneurones by other workers. Differences between these results and those of others working on neurons in vitro are ascribed to the immature nature of the cells studied here.