title: Fear conditioning alters neuron-specific hippocampal place field stability via the basolateral amygdala.
abstract: It is well established that physical changes to an environment result in plasticity of hippocampal place cell activity, while in the absence of changes, place fields are remarkably stable. Manipulations of a rat's perception of the environment without physically changing the environment also result in plasticity of place cell firing. Here, we tested the hypothesis that a rat's perception of an environment could be changed by introducing an auditory fear-conditioned stimulus (CS) to a previously neutral environment, inducing plasticity of hippocampal place fields. First, stable place fields were isolated for rats exploring a radial-arm maze in one environment, and then the rats were fear-conditioned to an auditory CS in a completely separate environment. Later, the CS was specifically paired once with a location in the previously neutral radial-arm maze, either within the given neuron's place field (in-field) or an area outside of the place field (out-of-field). A single, paired presentation of the CS with a location in-field for a specific place cell disrupted the stability of that neuron's place field, whereas pairing the CS with a location out-of-field did not affect place field stability. We further showed that this place field disruption for a CS presented in-field was mediated by inputs from the basolateral amygdala (BLA). Temporarily inactivating the BLA immediately post-CS re-exposure attenuated the CS-induced place field destabilization. Our results show neuron-specific conditional plasticity for actively firing hippocampal place cells, and that the BLA mediates this plasticity when an emotionally arousing or fear-related CS is used.
authors.affiliation: Cognition & Neuroscience Program, Behavioral & Brain Sciences, The University of Texas at Dallas, 800W. Campbell Rd., GR4.1, Richardson, TX 75080-3021, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Donzis
authors.forename: R L
authors.initials: RL
authors.lastname: Rennaker
authors.forename: L T
authors.initials: LT
authors.lastname: Thompson
mesh_terms: D000679:Amygdala / Q000502:physiology*; D000818:Animals; D003214:Conditioning, Classical; D005239:Fear; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception / Q000502:physiology
keywords: Auditory fear conditioning; Basolateral amygdala; CA1; Hippocampus; Place cells; Plasticity