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Updated: Jun 11, 2026
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Fluorescent Calcium Imaging and Subsequent In Situ Hybridization for Neuronal Precursor Characterization in Xenopus laevis
Published on: February 18, 2020
cJun integrates calcium activity and tlx3 expression to regulate neurotransmitter specification
Kurt W Marek1, Lisa M Kurtz, Nicholas C Spitzer
1Neurobiology Section, Division of Biological Sciences and Center for Neural Circuits, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, California, USA. kmarek@ucsd.edu
Nature Neuroscience
|June 29, 2010
Summary
Early neuronal activity, specifically calcium spikes, influences neurotransmitter choice in developing spinal cord neurons by regulating the tlx3 gene via cJun transcription factor. This discovery reveals a novel mechanism for activity-dependent neuronal development.
Area of Science:
- Neuroscience
- Developmental Biology
- Molecular Biology
Background:
- Neuronal differentiation traditionally relies on genetic factors and morphogen gradients.
- Early neuronal activity's role in differentiation, particularly before synapse formation, was unclear.
- Recent evidence suggests activity influences early neuronal development and phenotypic specification.
Purpose of the Study:
- To elucidate the mechanism linking endogenous calcium activity to genetic pathways for neurotransmitter choice.
- To investigate how early neuronal activity regulates neurotransmitter phenotype in the embryonic spinal cord.
- To identify the molecular players involved in activity-dependent neurotransmitter specification.
Main Methods:
- Utilized Xenopus tropicalis model system for studying early neuronal development.
- Investigated the role of endogenous calcium spike activity in modulating gene transcription.
- Analyzed the interaction between calcium signaling, cJun transcription factor, and the tlx3 gene promoter.
Main Results:
- Identified a mechanism where early calcium spike activity modulates tlx3 gene transcription.
- Demonstrated that cJun transcription factor binds to a variant cAMP response element (CRE) in the tlx3 promoter.
- Showed calcium signaling through cJun N-terminal phosphorylation integrates activity-dependent and intrinsic pathways for neurotransmitter specification.
Conclusions:
- Early neuronal activity directly regulates genetic pathways at critical developmental decision points.
- Calcium signaling via cJun phosphorylation is a key mechanism for specifying neurotransmitter choice in developing neurons.
- This provides a basis for understanding how neuronal activity shapes developing nervous systems.
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