Neurons Activated During Fear Memory Consolidation and Reconsolidation are Mapped to a Common and New Topography in the Lateral Amygdala

Bergstrom, Hadley C., McDonald, Craig G., Dey, Smita, Fernandez, Gina M., & Johnson, Luke R. (2013) Neurons Activated During Fear Memory Consolidation and Reconsolidation are Mapped to a Common and New Topography in the Lateral Amygdala. Brain Topography, 26(3), pp. 468-478.

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A key question in neuroscience is how memory is selectively allocated to neural networks in the brain. This question remains a significant research challenge, in both rodent models and humans alike, because of the inherent difficulty in tracking and deciphering large, highly dimensional neuronal ensembles that support memory (i.e., the engram). In a previous study we showed that consolidation of a new fear memory is allocated to a common topography of amygdala neurons. When a consolidated memory is retrieved, it may enter a labile state, requiring reconsolidation for it to persist. What is not known is whether the original spatial allocation of a consolidated memory changes during reconsolidation. Knowledge about the spatial allocation of a memory, during consolidation and reconsolidation, provides fundamental insight into its core physical structure (i.e., the engram). Using design-based stereology, we operationally define reconsolidation by showing a nearly identical quantity of neurons in the dorsolateral amygdala (LAd) that expressed a plasticity-related protein, phosphorylated mitogen-activated protein kinase, following both memory acquisition and retrieval. Next, we confirm that Pavlovian fear conditioning recruits a stable, topographically organized population of activated neurons in the LAd. When the stored fear memory was briefly reactivated in the presence of the relevant conditioned stimulus, a similar topography of activated neurons was uncovered. In addition, we found evidence for activated neurons allocated to new regions of the LAd. These findings provide the first insight into the spatial allocation of a fear engram in the LAd, during its consolidation and reconsolidation phase.

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2 citations in Web of Science®

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ID Code: 64166
Item Type: Journal Article
Refereed: Yes
Keywords: Mapping; Micro anatomy; Pavlovian; Stable; Topography; Unbiased stereology, animal experiment; article; brain mapping; conditioning; controlled study; fear; lateral amygdala; male; memory consolidation; nerve cell; neuroanatomy; nonhuman; priority journal; protein expression; rat; spatial memory; stereology
DOI: 10.1007/s10548-012-0266-6
ISSN: 1573-6792
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > NEUROSCIENCES (110900)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Schools > School of Psychology & Counselling
Copyright Owner: Springer
Deposited On: 07 Nov 2013 10:40
Last Modified: 08 Nov 2013 00:57

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