Synaptic Plasticity, Engrams, and Network Oscillations in Amygdala Circuits for Storage and Retrieval of Emotional Memories

Neuron. 2017 May 17;94(4):731-743. doi: 10.1016/j.neuron.2017.03.022.


The neuronal circuits of the basolateral amygdala (BLA) are crucial for acquisition, consolidation, retrieval, and extinction of associative emotional memories. Synaptic plasticity in BLA neurons is essential for associative emotional learning and is a candidate mechanism through which subsets of BLA neurons (commonly termed "engram") are recruited during learning and reactivated during memory retrieval. In parallel, synchronous oscillations in the theta and gamma bands between the BLA and interconnected structures have been shown to occur during consolidation and retrieval of emotional memories. Understanding how these cellular and network phenomena interact is vital to decipher the roles of emotional memory formation and storage in the healthy and pathological brain. Here, we review data on synaptic plasticity, engrams, and network oscillations in the rodent BLA. We explore mechanisms through which synaptic plasticity, engrams, and long-range synchrony might be interconnected.

Keywords: amygdala; engrams; fear; interneurons; memory; oscillations; synaptic plasticity.

Publication types

  • Review

MeSH terms

  • Amygdala / physiology*
  • Animals
  • Appetitive Behavior
  • Association Learning / physiology*
  • Basolateral Nuclear Complex / physiology
  • Brain Waves / physiology*
  • Cerebral Cortex / physiology
  • Conditioning, Psychological / physiology*
  • Delta Rhythm / physiology
  • Emotions / physiology*
  • Fear / physiology
  • Gamma Rhythm / physiology
  • Humans
  • Long-Term Potentiation / physiology
  • Memory / physiology*
  • Mental Recall
  • Nerve Net
  • Neural Pathways
  • Neuronal Plasticity / physiology*
  • Thalamus / physiology
  • Theta Rhythm / physiology