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Published on: February 12, 2014
Developmental changes in the subcellular localization of calretinin.
N J Hack1, M C Wride, K M Charters
1Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA. Nicola.Hack@hsc.utah.edu
Summary
Calretinin (CR) in chick brainstem auditory neurons shifts from diffuse to membrane-associated localization during development. This change coincides with neuronal activity and may help manage calcium influxes.
Area of Science:
- Neuroscience
- Cell Biology
- Developmental Biology
Background:
- Brainstem auditory neurons in the chick nucleus magnocellularis (NM) express high levels of calretinin (CR).
- Calretinin (CR) has been traditionally viewed as a diffusible calcium buffer within the cytosol.
Purpose of the Study:
- To investigate the developmental changes in calretinin (CR) localization within chick NM neurons.
- To understand the functional implications of CR's subcellular distribution in auditory pathway development.
Main Methods:
- High-resolution confocal microscopy was employed to visualize CR distribution.
- Biochemical analyses were conducted to characterize CR's association with cellular membranes.
Main Results:
- During NM neuron development, CR transitioned from diffuse, low-concentration expression to high concentration beneath the plasma membrane.
- This subcellular localization shift occurred concurrently with the onset of spontaneous activity, synaptic transmission, and synapse refinement.
- CR's membrane association was found to be detergent-soluble and calcium-independent, unlike calmodulin which remained diffusely expressed.
Conclusions:
- The developmental redistribution of calretinin (CR) to the plasma membrane in NM neurons is a unique event in the chick brainstem auditory pathway.
- This localization suggests an adaptation to manage calcium influxes in highly active neurons with numerous Ca2+-permeable AMPA receptors.
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