Different activity patterns control various stages of Reelin synthesis in the developing neocortex

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• Reelin is a crucial extracellular matrix protein for mammalian neocortical development.
• It guides neuronal migration and cortical layer formation, initially secreted by Cajal-Retzius cells and later by GABAergic neurons.

Purpose of the Study:

• To profile Reelin expression in the mouse neocortex during the first three postnatal weeks.
• To investigate the role of neuronal electrical activity in regulating Reelin synthesis and secretion.

Main Methods:

• Cell-type specific profiling of Reelin expression.
• Manipulation of neuronal electrical activity (activity increase and silencing).
• Analysis of Reelin transcription, translation, and secretion.

Main Results:

• Increased electrical activity promotes Reelin transcription via the BDNF/TrkB pathway but doesn't affect translation or secretion.
• Neuronal network silencing enhances Reelin translation without altering transcription or secretion.
• Reelin secretion appears to be constitutive, independent of activity patterns.

Conclusions:

• Different patterns of neuronal electrical activity differentially regulate Reelin synthesis at transcriptional and translational levels.
• Reelin secretion is largely independent of neuronal activity during early postnatal development.