title: Myosin II motor activity in the lateral amygdala is required for fear memory consolidation.
abstract: Learning induces dynamic changes to the actin cytoskeleton that are required to support memory formation. However, the molecular mechanisms that mediate filamentous actin (F-actin) dynamics during learning and memory are poorly understood. Myosin II motors are highly expressed in actin-rich growth structures including dendritic spines, and we have recently shown that these molecular machines mobilize F-actin in response to synaptic stimulation and learning in the hippocampus. In this study, we report that Myosin II motors in the rat lateral amygdala (LA) are essential for fear memory formation. Pretraining infusions of the Myosin II inhibitor, blebbistatin (blebb), disrupted long term memory, while short term memory was unaffected. Interestingly, both post-training and pretesting infusions had no effect on memory formation, indicating that Myosin II motors operate during or shortly after learning to promote memory consolidation. These data support the idea that Myosin II motor-force generation is a general mechanism that supports memory consolidation in the mammalian CNS.
authors.affiliation: Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, USA.
authors.forename: Cristin F
authors.initials: CF
authors.lastname: Gavin
authors.forename: Maria D
authors.initials: MD
authors.lastname: Rubio
authors.forename: Erica
authors.initials: E
authors.lastname: Young
authors.forename: Courtney
authors.initials: C
authors.lastname: Miller
authors.forename: Gavin
authors.initials: G
authors.lastname: Rumbaugh
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001245:Association Learning / Q000187:drug effects / Q000502:physiology; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D049229:Dendritic Spines / Q000187:drug effects / Q000378:metabolism; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D024501:Nonmuscle Myosin Type IIB / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000187:drug effects / Q000378:metabolism
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; C472645:blebbistatin; D024501:Nonmuscle Myosin Type IIB