RegenLab
Neuroscience

The Role of Extracellular Matrix Degradation in Supporting Synaptic Plasticity During Brain Development

2026-01-05

Journal Information

Summary

Using the zebrafish brain, this study revealed the crucial role that degradation of the extracellular matrix (ECM) plays in synaptic plasticity during brain development. Through live imaging, the researchers confirmed the existence of dynamic and stable synapses, and showed that matrix metalloproteinase 14 (MMP14) is secreted by microglia and degrades Brevican, a major component of the ECM, thereby regulating the lifespan of dynamic synapses and controlling experience-dependent synaptic plasticity.

Background

Synaptic plasticity is the neural basis of learning and memory and plays an important role in brain development. The extracellular matrix (ECM) is a complex network surrounding the cells in the brain and is known to regulate synaptic plasticity. However, the influence of the ECM on synaptic plasticity during the developmental period, and its molecular mechanism, remain insufficiently understood.

Key Findings (Molecular, Cellular, and Tissue Levels)

The main findings of this study are as follows.

  1. Bimodal distribution of synapse dynamics: Excitatory synapses in the zebrafish hindbrain can be divided into two groups: short-lived “dynamic synapses” and long-lived “stable synapses.”
    • This can be compared, for example, to a playground. Dynamic synapses, like swings where children play temporarily, frequently repeat cycles of appearing and disappearing. Stable synapses, on the other hand, persist for a long time, like the large slide that is the symbol of the playground.
  2. The importance of ECM degradation: Inhibiting the degradation of the ECM destabilizes dynamic synapses and reduces synaptic density.
    • The image is that if the foundation (ECM) supporting the playground equipment (synapses) collapses, the equipment (synapses) topples over, and the children (neural activity) can no longer play.
  3. The role of MMP14: Loss of MMP14 leads to the accumulation of Brevican, prolongs the lifespan of dynamic synapses, and increases synaptic density.
    • MMP14 is like the maintenance worker of the playground. When trash (Brevican) accumulates around the equipment (synapses), the equipment (synapses) becomes difficult to use, but by having the maintenance worker (MMP14) remove the trash (Brevican), the equipment (synapses) can be used comfortably.
  4. The involvement of microglia: Microglia-derived MMP14 is essential for the regulation of synaptic plasticity.
    • Microglia are like the security guards of the playground. Not only do they keep the playground safe, but by also maintaining the equipment (synapses), they provide an environment where the children (neural activity) can play with peace of mind.
  5. Experience-dependent synaptic plasticity: Both MMP14 and Brevican are necessary for experience-dependent synaptic plasticity in motor learning.
    • The children playing in the playground (neural activity) grow through various experiences. When the arrangement and types of equipment (synapses) change, the way the children (neural activity) play also changes, allowing them to acquire new skills. MMP14 and Brevican support the growth of the children (neural activity) by changing the arrangement and types of the playground equipment (synapses).

Discussion / Implications

This study clearly demonstrated that ECM remodeling plays an important role in synaptic plasticity during brain development. This finding also carries important implications from the perspectives of anti-aging, regenerative medicine, and neuro–organ crosstalk.

Anti-aging

It is known that with aging, the ECM structure within the brain changes and synaptic plasticity declines. A decline in MMP14 activity and the accumulation of Brevican may be a contributing factor to the cognitive decline associated with aging. The findings of this study suggest that by maintaining MMP14 activity or suppressing the accumulation of Brevican, it may be possible to halt the age-related decline in synaptic plasticity and help preserve cognitive function.

Regenerative Medicine (MSC / EV)

Mesenchymal stem cells (MSC) and their extracellular vesicles (EV) have been reported to have neuroprotective and neuroregenerative effects. MSCs/EVs may improve synaptic plasticity by promoting MMP14 expression or by regulating ECM degradation. The findings of this study may serve as an important foundation for developing therapeutic strategies for neurological disorders using regenerative medicine based on MSC/EV.

Neuro–Organ Crosstalk

In recent years, it has become clear that interactions between the brain and other organs affect various physiological functions and diseases. The ECM may play a role in regulating information transmission between the brain and other organs. The findings of this study may provide an important clue for understanding the role of the ECM in neuro–organ crosstalk, such as the brain–gut axis and the brain–immune axis.

Future Prospects

This study not only revealed the importance of ECM remodeling in brain development but also suggested directions for future research. Future studies will need to focus on the following points.

Conclusion

Using zebrafish, this study revealed that ECM remodeling plays an important role in synaptic plasticity during brain development. It showed that MMP14 is secreted by microglia and degrades Brevican, thereby regulating the lifespan of dynamic synapses and controlling experience-dependent synaptic plasticity. The findings of this study carry important implications from the perspectives of anti-aging, regenerative medicine, and neuro–organ crosstalk, and are expected to contribute to the future advancement of neuroscience research.