Measurement of glial transport currents in microcultures: Application to excitatory neurotransmission

We have found microcultures of neurons and astrocytes to provide a useful experimental preparation for studying the role of glutamate transporters in synaptic physiology. The preparation balances experimental control over a number of important variables with an environment that mimics many fundamental features of synapses in situ. Several avenues exist for further use of microcultures in the study of transporters. Although our studies have focused primarily on the role of transporters in the new milliseconds subsequent to individual synaptic events, it is likely that microcultures may prove useful for studying slower effects of transporters in maintaining or modulating tonic ambient glutamate levels. Another avenue for further research is to understand which of the several cloned glutamate transporters may be responsible for the observed physiological effects of transporters in microcultures. Finally, because a number of neuronal transmitter phenotypes have been shown to survive in the microculture environment, it may be possible to extend studies of transmitter transport to other transmitter phenotypes and to other nervous system regions.