Development of GABAergic function of dissociated hippocampal cultures from fetal mice

The GABA uptake mechanism has been characterized in hippocampal cell cultures prepared from fetal mice of 13-19 days gestational age [3H]GABA is accumulated selectively by neuronal cells by a high-affinity (Km = 3 micro M) mechanism that is an early property of the neurons. Autoradiography of [3H]GABA uptake revealed that approximately 30% of the neuronal cells had uptake. A unique small neuronal type did not have [3H]GABA uptake but was found to have [3H]glutamic acid uptake, suggesting that these neurons may be granule cells. The selective labeling of neurons with [3H]GABA and [3H]glutamic acid is consistent with the idea that high-affinity uptake of a transmitter may be unique to neurons that use that transmitter.