Effect of potassium on neuron survival in cultures of dissociated human nervous tissue

In a previous study it had been observed that the optimal K+ concentration with respect to the survival of dissociated chick neurons in culture was approximately 40.8 mm. The objective of the present study was simply to ascertain if increased K+ in the culture medium would have a similiar effect on the survival of dissociated human neurons. A quantitative technique developed for chick material proved even more successful for human material. Spinal ganglia were dissected from fetuses obtained at therapeutic abortions. The fetuses ranged in age from 10–16 weeks in utero. The optimal K+ concentration for human neurons was found to be 20.8 mm. The dissociated human ganglia underwent a progressive morphological development in culture quite similar to that of the dissociated chick ganglia, and the effect of elevated K+ on the morphology was also similar for both cases. These facts suggest a generality with respect to species of the observed effects of high K+ levels. The high K+ concentration found optimal for both chick and human neuron survival suggests a reconsideration of the K+ level used routinely for culturing dissociated nervous tissue. This study has demonstrated that a quantitative method has been developed for studying the effect of the physical and chemical environment on dissociated human nervous tissue. This technique provides a new tool which may prove useful in a number of lines of medical research.