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Extinction Training During the Reconsolidation Window Prevents Recovery of Fear
Published on: August 24, 2012
Perineuronal nets protect fear memories from erasure
Nadine Gogolla1, Pico Caroni, Andreas Lüthi
1Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
Science (New York, N.Y.)
|September 5, 2009
Summary
In adult animals, fear memories are protected from extinction by perineuronal nets (PNNs). Degrading these nets in adults makes fear memories erasable, revealing a key mechanism for memory resilience.
Area of Science:
- Neuroscience
- Molecular Biology
- Developmental Biology
Background:
- Fear conditioning in adults creates permanent memories resistant to extinction.
- In contrast, young animals can erase conditioned fear memories through extinction.
- This suggests a developmental shift in fear memory processing and protection.
Purpose of the Study:
- To investigate the molecular mechanisms underlying the developmental switch in fear memory resilience.
- To identify the role of extracellular matrix components in protecting fear memories from extinction in adults.
Main Methods:
- Examined the role of chondroitin sulfate proteoglycans (CSPGs) and their organization into perineuronal nets (PNNs) in the amygdala.
- Investigated the effect of degrading PNNs using chondroitinase ABC on fear memory erasure in adult animals.
Main Results:
- The organization of CSPGs into PNNs in the amygdala coincided with the developmental increase in fear memory resilience.
- Degradation of PNNs in adult animals rendered newly acquired fear memories susceptible to erasure by extinction.
- Intact PNNs were shown to be crucial for the formation of erasure-resistant fear memories.
Conclusions:
- Extracellular matrix chondroitin sulfate proteoglycans (CSPGs) organized into perineuronal nets (PNNs) in the amygdala confer resistance to fear memory erasure in adult animals.
- PNNs mediate the formation of permanent fear memories, effectively closing a postnatal critical period for memory erasure.
- This study identifies a molecular mechanism for the developmental transition of fear memory plasticity.
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