In vitro studies of dissociated cells from newborn mouse dorsal root ganglia

Abstract

Dorsal root ganglia were dissected from newborn mice and dissociated with yields of about 6,000 neurons, and approximately equal numbers of non-neuronal cells, per ganglion. Dispersed cell cultures of these mouse ganglionic dissociates revealed that attachment, fiber growth and prolonged survival of their neurons were markedly dependent on the availability of exogenous nerve growth factor (NGF) in the culture medium. In contrast, the undissociated ganglia had failed to exhibit a fiberoutgrowth response in the classical NGF bioassay. Attachment and fiber production abilities of the dissociated neurons were also greatly enhanced by the addition of non-neuronal cells obtained from the same ganglionic source and this non-neuronal supplementation could substitute — at least for a limited time — for the otherwise required NGF. Neurons and dispersed non-neurons of the ganglionic dissociate attached to collagen with different time courses and could, thus, be separated from each other: the neuronal fraction, however, was not pure as many of the neurons remained studded with satellite cells through the dissociation and fractionation steps. Preliminary experiments suggested that neuronal attachment and fiber production would not occur in the cultures of a purified neuronal fraction, even in the presence of NGF, unless non-neuronal elements were resupplied to them.