title: Dopamine-dependent synaptic plasticity in an amygdala inhibitory circuit controls fear memory expression.
abstract: Of the numerous events that occur in daily life, we readily remember salient information, but do not retain most less-salient events for a prolonged period. Although some of the episodes contain putatively emotional aspects, the information with lower saliency is rarely stored in neural circuits via an unknown mechanism. We provided substantial evidence indicating that synaptic plasticity in the dorsal ITC of amygdala allows for selective storage of salient emotional experiences, while it deters less-salient experience from entering long-term memory. After activation of D4R or weak fear conditioning, STDP stimulation induces LTD in the LA-ITC synapses. This form of LTD is dependent upon presynaptic D4R, and is likely to result from enhancement of GABA release. Both optogenetic abrogation of LTD and ablation of D4R at the dorsal ITC in vivo lead to heightened and over-generalized fear responses. Finally, we demonstrated that LTD was impaired at the dorsal ITC of PTSD model mice, which suggests that maladaptation of GABAergic signaling and the resultant LTD impairment contribute to the endophenotypes of PTSD.
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
authors.forename: Joo Han
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
authors.forename: Joung-Hun
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000679:Amygdala / Q000378:metabolism*; D000818:Animals; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism*; D005239:Fear; D007395:Interneurons / Q000378:metabolism; D008568:Memory; D051379:Mice; D009473:Neuronal Plasticity / Q000502:physiology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D050638:Receptors, Dopamine D4 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013313:Stress Disorders, Post-Traumatic / Q000378:metabolism / Q000473:pathology; D009435:Synaptic Transmission
chemical_list: D034741:RNA, Small Interfering; D050638:Receptors, Dopamine D4; D004298:Dopamine