title: Activity-dependent structural plasticity after aversive experiences in amygdala and auditory cortex pyramidal neurons.
abstract: The brain is highly plastic and undergoes changes in response to many experiences. Learning especially can induce structural remodeling of dendritic spines, which is thought to relate to memory formation. Classical Pavlovian fear conditioning (FC) traditionally pairs an auditory cue with an aversive footshock, and has been widely used to study neural processes underlying associative learning and memory. Past research has found dendritic spine changes after FC in several structures. But, due to heterogeneity of cells within brain structures and limitations of traditional neuroanatomical techniques, it is unclear if all cells included in analyses were actually active during learning processes, even if known circuits are isolated. In this study, we employed a novel approach to analyze structural plasticity explicitly in neurons activated by exposure to either cued or uncued footshocks. We used male and female Arc-dVenus transgenic mice, which express the Venus fluorophore driven by the activity-related Arc promoter, to identify neurons that were active during either scenario. We then targeted fluorescent microinjections to Arc+ and neighboring Arc- neurons in the basolateral area of the amygdala (BLA) and auditory association cortex (TeA). In both BLA and TeA, Arc+ neurons had reduced thin and mushroom spine densities compared to Arc- neurons. This effect was present in males and females alike and also in both cued and uncued shock groups. Overall, this study adds to our understanding of how neuronal activity affects structural plasticity, and represents a methodological advance in the ways we can directly relate structural changes to experience-related neural activity.
authors.affiliation: Psychology Department, Northeastern University, Boston, MA, United States.
authors.forename: Tina
authors.initials: T
authors.lastname: Gruene
authors.affiliation: Psychology Department, Northeastern University, Boston, MA, United States.
authors.forename: Katelyn
authors.initials: K
authors.lastname: Flick
authors.affiliation: Psychology Department, Northeastern University, Boston, MA, United States; Genetics Department, Harvard Medical School, Boston, MA, United States.
authors.forename: Sam
authors.initials: S
authors.lastname: Rendall
authors.affiliation: Genetics Department, Harvard Medical School, Boston, MA, United States.
authors.forename: Jin Hyung
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Genetics Department, Harvard Medical School, Boston, MA, United States.
authors.forename: Jesse
authors.initials: J
authors.lastname: Gray
authors.affiliation: Psychology Department, Northeastern University, Boston, MA, United States. Electronic address: r.shansky@neu.edu.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Shansky
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003213:Conditioning, Psychological / Q000502:physiology; D003463:Cues; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D049229:Dendritic Spines / Q000502:physiology*; D004597:Electroshock; D005239:Fear / Q000502:physiology; D005260:Female; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology*; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein; C054562:yellow fluorescent protein, Bacteria
keywords: Arc; amygdala; dendritic spines; structural plasticity