Long-term cultures of neurons from adult frog brain express GABA and glutamate-activated channels.

Cells from adult Xenopus laevis brainstem and spinal cord were dissociated with mild enzymatic treatment and grown in long-term cell culture. These cells had specific attachment/substrate and medium/serum requirements. Cells with bipolar and multipolar morphology were positively identified as neurons using immunohistochemistry with monoclonal antibodies to rat and bovine neurofilament proteins which we show here cross-react with similar amphibian proteins. Patch clamp recordings demonstrated that these neurons have populations of ionic channels which are activated by L-glutamate or gamma-aminobutyric acid (GABA). The characteristics of these channels were similar to those previously described for GABA- and glutamate-activated channels in embryonic mammalian neurons isolated in culture. Cell cultures of neurons isolated from adult Xenopus laevis brain may be a useful and simple preparation with which to examine the modulation of neuronal properties by various agents over longer time intervals then has been previously possible.