Neurotransmitter Synthesis by Neuroblastoma ClonesTakehiko Amano, Elliott Richelson, Marshall W. Nirenberg|Proceedings of the National Academy of Sciences|1972 Neuroblastoma clones were examined for choline acetyltransferase (EC 2.3.1.6), tyrosine hydroxylase (EC 1.14.3.a), acetylcholinesterase (EC 3.1.1.7), and also for neurite formation. One clone does not form axons or dendrites. Three types of clones were found with respect to neurotransmitter synthesis: cholinergic, adrenergic, and clones that do not synthesize acetylcholine or catechols. All clones contain acetylcholinesterase. These results show that genes determining neurotransmitter species can be expressed in dividing cells, that the parental programs of gene expression are inherited, and that dividing cells can be programmed with respect to their ability to communicate with other cells.
Regulation of Axon Formation by Clonal Lines of a Neural TumorNicholas W. Seeds, Alfred G. Gilman, Takehiko Amano et al.|Proceedings of the National Academy of Sciences|1970 Clonal lines of neuroblastoma cells were found to extend or retract axons depending upon the concentration of serum. Neurite extension was not inhibited by cycloheximide but was sensitive to colchicine or vinblastine, suggesting that neurite formation is dependent upon the assembly of microtubules or neurofilaments from preformed protein subunits.
Sarcoma viruses carrying ras oncogenes induce differentiation-associated properties in a neuronal cell lineHigh activity of choline acetyltransferase induced in neuroblastoma X glia hybrid cellsElectrogenesis in mouse neuroblastoma cells <i>In vitro</i>P. G. Nelson, J.H. Peacock, Takehiko Amano et al.|Journal of Cellular Physiology|1971 Abstract Intracellular microelectrode studies of passive membrane properties and action potential generation were carried out on cloned and uncloned mouse neuroblastoma cells in tissue culture. The cloned cells were studied between the eighth and tenth months and the uncloned cells between the third and fifth weeks after primary dissociation. Electrophysiologic measurements of cell membrane properties were made by passing stimulating current pulses across the cell membrane from an intracellular microelectrode and recording simultaneously from the same electrode, by means of a bridge circuit, the changes in membrane potential. The range of responses to electrical stimulation varied from passive increases in membrane potential to repetitive firing of action potentials. A 20 fold range in spike generating capability was found. Passive membrane properties (membrane potential, specific membrane resistivity, and specific membrane capacitance) were similar to those of sympathetic neurons in intact preparations. Seventy‐nine percent of the cloned cell line compared to 94% of the uncloned line were capable of generating action potentials. Less than 2% of the cloned cells showed repetitive firing whereas 23% of the uncloned cells had this property. As in several types of normal neurons, the action potential mechanism was largely, although not completely, blocked by iontophoretic and bath applied tetrodotoxin.