Identifying monoaminergic, GABAergic, and cholinergic characteristics in immortalized neuronal cell lines

We measured the concentration of neurotransmitters in immortalized neural cell lines of hippocampal, septal, brainstem and cerebellar origin. While in most of the cell lines, concentrations of monoamines, gamma-aminobutyric acid (GABA) and acetylcholine were low, in some they were markedly higher. This made it quite easy to identify possible monoaminergic, GABAergic or cholinergic cell lines. However all the cell lines contained glutamate and aspartate and there were no outstanding differences in levels of these amino acids differences between the cell lines. Deprivation of serum, which made the cells acquire a more differentiated morphology, caused an increase in the intracellular concentrations of some compounds and a switch from multiple to a single transmitter in the case of some cell lines. It suggested that measurement of transmitter concentrations combined with serum deprivation studies, may provide an indication of the neurochemical characteristics of immortalised neuronal cell lines.