Premium
Calcium dependence of differentiation of GABA immunoreactivity in spinal neurons
Author(s) -
Spitzer Nicholas C.,
Debaca Rosario C.,
Allen Keith A.,
Holliday Janet
Publication year - 1993
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903370111
Subject(s) - biology , xenopus , calcium , neuroscience , calcium imaging , calcium in biology , neurotransmitter , voltage dependent calcium channel , microbiology and biotechnology , intracellular , gamma aminobutyric acid , electrophysiology , central nervous system , medicine , biochemistry , receptor , gene
Abstract The developmental regulation of neurotransmitter synthesis has been extensively studied and appears in many cases to depend on electrical activity. The central nervous system of the Xenopus embryo and young larva is an attractive subject for such studies, since action potentials first elicited from Xenopus spinal neurons at the time of closure of the neural tube are long in duration and calcium‐dependent. Moreover, cells exhibit spontaneous elevations of intracellular calcium during this early period as a consequence of calcium influx through voltage‐dependent channels, which induces calcium release from intracellular stores. Since the early differentiation of Xenopus spinal neurons in dissociated cell culture parallels development in vivo, we have examined the maturation of γ‐aminobutyric acid (GABA) immunoreactivity in cultured neurons and explored its dependence on spontaneous calcium influx at early stages of development. We find that specific GABA immunoreactivity develops in spinal neurons in dissociated cell culture with the same time course previously defined in vivo. Additionally, this process requires calcium influx that occurs spontaneously through voltage‐dependent channels. The appearance of GABA immunoreactivity is blocked by transcriptional inhibitors. The early appearance of GABA raises the possibility that it may play additional roles at early stages of development. © 1993 Wiley‐Liss,Inc.