Abatis, MariosPerin, RodrigoNiu, Ruifangvan den Burg, ErwinHegoburu, ChloeKim, RyangOkamura, MichikoBito, HaruhikoMarkram, HenryStoop, Ron2024-07-032024-07-032024-07-032024-06-1310.1038/s41593-024-01676-6https://infoscience.epfl.ch/handle/20.500.14299/209058WOS:001247073900001The lateral amygdala (LA) encodes fear memories by potentiating sensory inputs associated with threats and, in the process, recruits 10-30% of its neurons per fear memory engram. However, how the local network within the LA processes this information and whether it also plays a role in storing it are still largely unknown. Here, using ex vivo 12-patch-clamp and in vivo 32-electrode electrophysiological recordings in the LA of fear-conditioned rats, in combination with activity-dependent fluorescent and optogenetic tagging and recall, we identified a sparsely connected network between principal LA neurons that is organized in clusters. Fear conditioning specifically causes potentiation of synaptic connections between learning-recruited neurons. These findings of synaptic plasticity in an autoassociative excitatory network of the LA may suggest a basic principle through which a small number of pyramidal neurons could encode a large number of memories.|A sparsely connected network, organized in clusters, identified in the rat lateral amygdala shows potentiation between recruited neurons after fear conditioning. This implies a mechanism for encoding multiple memories with a small number of neurons.Life Sciences & BiomedicineLong-Term PotentiationQuantal AnalysisPostsynaptic EfficacyPattern CompletionNmda ReceptorsMemoryConnectionsCompetitionExpressionSynapsestext::journal::journal article::research article