Perineuronal nets protect fear memories from erasure.
In adult animals, fear conditioning induces a permanent memory that is resilient to erasure by extinction. In contrast, during early postnatal development, extinction of conditioned fear leads to memory erasure, suggesting that fear memories are actively protected in adults. We show here that this protection is conferred by extracellular matrix chondroitin sulfate proteoglycans (CSPGs) in the amygdala. The organization of CSPGs into perineuronal nets (PNNs) coincided with the developmental switch in fear memory resilience. In adults, degradation of PNNs by chondroitinase ABC specifically rendered subsequently acquired fear memories susceptible to erasure. This result indicates that intact PNNs mediate the formation of erasure-resistant fear memories and identifies a molecular mechanism closing a postnatal critical period during which traumatic memories can be erased by extinction.
Gogolla
Nadine
N
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
Caroni
Pico
P
Lüthi
Andreas
A
Herry
Cyril
C
D000679:Amygdala / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D000818:Animals; D019765:Chondroitin ABC Lyase / Q000378:metabolism; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism / Q000502:physiology*; D003214:Conditioning, Classical; D003463:Cues; D005108:Extinction, Psychological; D005109:Extracellular Matrix / Q000502:physiology; D005239:Fear; D007858:Learning; D008297:Male; D008568:Memory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009473:Neuronal Plasticity
D011508:Chondroitin Sulfate Proteoglycans; D019765:Chondroitin ABC Lyase