title: Mechanisms underlying the formation of the amygdalar fear memory trace: A computational perspective.
abstract: Recent experimental and modeling studies on the lateral amygdala (LA) have implicated intrinsic excitability and competitive synaptic interactions among principal neurons (PNs) in the formation of auditory fear memories. The present modeling studies, conducted over an expanded range of intrinsic excitability in the network, revealed that only excitable PNs that received tone inputs participate in the competition. Strikingly, the number of model PNs integrated into the fear memory trace remained constant despite the much larger range considered, and model runs highlighted several conditioning-induced tone responsive characteristics of the various PN populations. Furthermore, these studies showed that although excitation was important, disynaptic inhibition among PNs is the dominant mechanism that keeps the number of plastic PNs stable despite large variations in the network's excitability. Finally, we found that the overall level of inhibition in the model network determines the number of projection cells integrated into the fear memory trace.
authors.affiliation: Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO, USA.
authors.forename: F
authors.initials: F
authors.lastname: Feng
authors.affiliation: Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO, USA.
authors.forename: P
authors.initials: P
authors.lastname: Samarth
authors.affiliation: Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, NJ, USA.
authors.forename: D
authors.initials: D
authors.lastname: Paré
authors.affiliation: Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO, USA. Electronic address: nairs@missouri.edu.
authors.forename: S S
authors.initials: SS
authors.lastname: Nair
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000679:Amygdala / Q000502:physiology*; D000818:Animals; D003198:Computer Simulation; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D005239:Fear / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000502:physiology*
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein
keywords: biophysical model; hebbian learning; sparse coding