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Myosin light chain kinase regulates synaptic plasticity and fear learning in the lateral amygdala

Citation

Lamprecht, R and Margulies, DS and Farb, CR and Hou, M and Johnson, LR and LeDoux, JE, Myosin light chain kinase regulates synaptic plasticity and fear learning in the lateral amygdala, Neuroscience, 139, (3) pp. 821-829. ISSN 0306-4522 (2006) [Refereed Article]

Copyright Statement

2006 Published by Elsevier Ltd on behalf of IBRO.

DOI: doi:10.1016/j.neuroscience.2005.12.055

Abstract

Learning and memory depend on signaling molecules that affect synaptic efficacy. The cytoskeleton has been implicated in regulating synaptic transmission but its role in learning and memory is poorly understood. Fear learning depends on plasticity in the lateral nucleus of the amygdala. We therefore examined whether the cytoskeletal-regulatory protein, myosin light chain kinase, might contribute to fear learning in the rat lateral amygdala. Microinjection of ML-7, a specific inhibitor of myosin light chain kinase, into the lateral nucleus of the amygdala before fear conditioning, but not immediately afterward, enhanced both short-term memory and long-term memory, suggesting that myosin light chain kinase is involved specifically in memory acquisition rather than in posttraining consolidation of memory. Myosin light chain kinase inhibitor had no effect on memory retrieval. Furthermore, ML-7 had no effect on behavior when the training stimuli were presented in a non-associative manner. Anatomical studies showed that myosin light chain kinase is present in cells throughout lateral nucleus of the amygdala and is localized to dendritic shafts and spines that are postsynaptic to the projections from the auditory thalamus to lateral nucleus of the amygdala, a pathway specifically implicated in fear learning. Inhibition of myosin light chain kinase enhanced long-term potentiation, a physiological model of learning, in the auditory thalamic pathway to the lateral nucleus of the amygdala. When ML-7 was applied without associative tetanic stimulation it had no effect on synaptic responses in lateral nucleus of the amygdala. Thus, myosin light chain kinase activity in lateral nucleus of the amygdala appears to normally suppress synaptic plasticity in the circuits underlying fear learning, suggesting that myosin light chain kinase may help prevent the acquisition of irrelevant fears. Impairment of this mechanism could contribute to pathological fear learning.

Item Details

Item Type:Refereed Article
Keywords:memory, PTSD, Amygdala
Research Division:Biomedical and Clinical Sciences
Research Group:Neurosciences
Research Field:Cellular nervous system
Objective Division:Health
Objective Group:Public health (excl. specific population health)
Objective Field:Mental health
UTAS Author:Johnson, LR (Associate Professor Luke Johnson)
ID Code:145139
Year Published:2006
Web of Science® Times Cited:20
Deposited By:Psychology
Deposited On:2021-07-02
Last Modified:2021-09-16
Downloads:0

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