Context-Dependent Encoding of Fear and Extinction Memories in a Large-Scale Network Model of the Basal Amygdala
2011 (English)In: PloS Computational Biology, ISSN 1553-734X, E-ISSN 1553-7358, Vol. 7, no 3, e1001104Article in journal (Refereed) Published
The basal nucleus of the amygdala (BA) is involved in the formation of context-dependent conditioned fear and extinction memories. To understand the underlying neural mechanisms we developed a large-scale neuron network model of the BA, composed of excitatory and inhibitory leaky-integrate-and-fire neurons. Excitatory BA neurons received conditioned stimulus (CS)-related input from the adjacent lateral nucleus (LA) and contextual input from the hippocampus or medial prefrontal cortex (mPFC). We implemented a plasticity mechanism according to which CS and contextual synapses were potentiated if CS and contextual inputs temporally coincided on the afferents of the excitatory neurons. Our simulations revealed a differential recruitment of two distinct subpopulations of BA neurons during conditioning and extinction, mimicking the activation of experimentally observed cell populations. We propose that these two subgroups encode contextual specificity of fear and extinction memories, respectively. Mutual competition between them, mediated by feedback inhibition and driven by contextual inputs, regulates the activity in the central amygdala (CEA) thereby controlling amygdala output and fear behavior. The model makes multiple testable predictions that may advance our understanding of fear and extinction memories.
Place, publisher, year, edition, pages
2011. Vol. 7, no 3, e1001104
article, basal amygdala, brain function, central nucleus (amygdala), conditioning, controlled study, fear, hippocampus, lateral amygdala, nerve cell network, nerve cell plasticity, prefrontal cortex, reinforcement, action potential, amygdaloid nucleus, animal, biological model, biology, cytology, fear, memory, nerve cell, physiology, reinforcement, rodent, synapse
IdentifiersURN: urn:nbn:se:kth:diva-154861DOI: 10.1371/journal.pcbi.1001104.g008ISI: 000288995500012PubMedID: 21437238ScopusID: 2-s2.0-79953671906OAI: oai:DiVA.org:kth-154861DiVA: diva2:758917
QC 201506232014-10-282014-10-282015-06-23Bibliographically approved