Publication Date:
2015-01-21
Description:
Fear memories allow animals to avoid danger, thereby increasing their chances of survival. Fear memories can be retrieved long after learning, but little is known about how retrieval circuits change with time. Here we show that the dorsal midline thalamus of rats is required for the retrieval of auditory conditioned fear at late (24 hours, 7 days, 28 days), but not early (0.5 hours, 6 hours) time points after learning. Consistent with this, the paraventricular nucleus of the thalamus (PVT), a subregion of the dorsal midline thalamus, showed increased c-Fos expression only at late time points, indicating that the PVT is gradually recruited for fear retrieval. Accordingly, the conditioned tone responses of PVT neurons increased with time after training. The prelimbic (PL) prefrontal cortex, which is necessary for fear retrieval, sends dense projections to the PVT. Retrieval at late time points activated PL neurons projecting to the PVT, and optogenetic silencing of these projections impaired retrieval at late, but not early, time points. In contrast, silencing of PL inputs to the basolateral amygdala impaired retrieval at early, but not late, time points, indicating a time-dependent shift in retrieval circuits. Retrieval at late time points also activated PVT neurons projecting to the central nucleus of the amygdala, and silencing these projections at late, but not early, time points induced a persistent attenuation of fear. Thus, the PVT may act as a crucial thalamic node recruited into cortico-amygdalar networks for retrieval and maintenance of long-term fear memories.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4376623/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4376623/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Do-Monte, Fabricio H -- Quinones-Laracuente, Kelvin -- Quirk, Gregory J -- G12 MD007600/MD/NIMHD NIH HHS/ -- K99 MH105549/MH/NIMH NIH HHS/ -- P50 MH086400/MH/NIMH NIH HHS/ -- P50-MH086400/MH/NIMH NIH HHS/ -- R01-MH058883/MH/NIMH NIH HHS/ -- R25 GM061838/GM/NIGMS NIH HHS/ -- R25-GM061838/GM/NIGMS NIH HHS/ -- R37 MH058883/MH/NIMH NIH HHS/ -- England -- Nature. 2015 Mar 26;519(7544):460-3. doi: 10.1038/nature14030. Epub 2015 Jan 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Psychiatry, University of Puerto Rico School of Medicine, PO Box 365067, San Juan 00936, Puerto Rico [2] Department of Anatomy &Neurobiology, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan 00936, Puerto Rico.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25600268" target="_blank"〉PubMed〈/a〉
Keywords:
Amygdala/cytology/physiology
;
Animals
;
Conditioning (Psychology)/physiology
;
Fear/*physiology
;
Male
;
Memory/*physiology
;
Neural Pathways/cytology/*physiology
;
Neurons/physiology
;
Optogenetics
;
Prefrontal Cortex/cytology/physiology
;
Proto-Oncogene Proteins c-fos/metabolism
;
Rats
;
Rats, Sprague-Dawley
;
Thalamus/cytology/physiology
;
Time Factors
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
