title: Context fear learning specifically activates distinct populations of neurons in amygdala and hypothalamus.
abstract: The identity and distribution of neurons that are involved in any learning or memory event is not known. In previous studies, we identified a discrete population of neurons in the lateral amygdala that show learning-specific activation of a c-fos-regulated transgene following context fear conditioning. Here, we have extended these studies to look throughout the amygdala for learning-specific activation. We identified two further neuronal populations, in the amygdalo-striatal transition area and medial amygdala, that show learning-specific activation. We also identified a population of hypothalamic neurons that show strong learning-specific activation. In addition, we asked whether these neurons are activated following recall of fear-conditioning memory. None of the populations of neurons we identified showed significant memory-recall-related activation. These findings suggest that a series of discrete populations of neurons are involved in fear learning in amygdala and hypothalamus. The lack of reactivation during memory recall suggests that these neurons either do not undergo substantial change following recall, or that c-fos is not involved in any such activation and change.
authors.affiliation: Department of Anatomy and Cell Biology, University of Melbourne, Melbourne, Victoria 3010, Australia.
authors.forename: Lidia
authors.initials: L
authors.lastname: Trogrlic
authors.forename: Yvette M
authors.initials: YM
authors.lastname: Wilson
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Newman
authors.forename: Mark
authors.initials: M
authors.lastname: Murphy
mesh_terms: D000679:Amygdala / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001245:Association Learning / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology; D005239:Fear / Q000502:physiology*; D007031:Hypothalamus / Q000378:metabolism / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D051379:Mice; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism
chemical_list: D016760:Proto-Oncogene Proteins c-fos