Abstract
Memories allow past experiences to guide future decision making and behavior. Sparse ensembles of neurons, known as engrams, are thought to store memories in the brain. Most previous research has focused on engrams supporting threatening or fearful memories where results show that neurons involved in a particular engram (“engram neurons”) are both necessary and sufficient for memory expression. Far less is understood about engrams supporting appetitive or rewarding memories. As circumstances and environments are dynamic, the fate of a previously acquired engram with changing circumstances is unknown. Here we examined how engrams supporting a rewarding cue-cocaine memory are formed and whether this original engram is important in reinstatement of memory-guided behavior following extinction. Using a variety of techniques, we show that neurons in the lateral amygdala are allocated to an engram based on relative neuronal excitability at training. Furthermore, once allocated, these neurons become both necessary and sufficient for behavior consistent with recall of that rewarding memory. Allocated neurons are also critical for cocaine-primed reinstatement of memory-guided behavior following extinction. Moreover, artificial reactivation of initially allocated neurons supports reinstatement-like behavior following extinction even in the absence of cocaine-priming. Together, these findings suggest that cocaine priming after extinction reactivates the original engram, and that memory-guided reinstatement behavior does not occur in the absence of this reactivation. Although we focused on neurons in one brain region only, our findings that manipulations of lateral amygdala engram neurons alone were sufficient to impact memory-guided behavior indicate that the lateral amygdala is a critical hub region in what may be a larger brain-wide engram.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 13 print issues and online access
$259.00 per year
only $19.92 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Tonegawa S, Liu X, Ramirez S, Redondo R. Memory Engram Cells Have Come of Age. Neuron. 2015;87:918–31. https://doi.org/10.1016/j.neuron.2015.08.002.
Josselyn SA, Kohler S, Frankland PW. Finding the engram. Nat Rev Neurosci. 2015;16:521–34. https://doi.org/10.1038/nrn4000.
Josselyn SA, Kohler S, Frankland PW. Heroes of the Engram. J Neurosci. 2017;37:4647–57. https://doi.org/10.1523/JNEUROSCI.0056-17.2017.
Eichenbaum H. Still searching for the engram. Learn Behav. 2016;44:209–22. https://doi.org/10.3758/s13420-016-0218-1.
Denny CA, Lebois E, Ramirez S. From Engrams to Pathologies of the Brain. Frontiers in neural circuits. 2017;11. https://doi.org/10.3389/fncir.2017.00023.
Tanaka KZ, Pevzner A, Hamidi AB, Nakazawa Y, Graham J, Wiltgen BJ. Cortical representations are reinstated by the hippocampus during memory retrieval. Neuron. 2014;84:347–54. https://doi.org/10.1016/j.neuron.2014.09.037.
Park S, Kramer EE, Mercaldo V, Rashid AJ, Insel N, Frankland PW, et al. Neuronal Allocation to a Hippocampal Engram. Neuropsychopharmacology. 2016. https://doi.org/10.1038/npp.2016.73.
Ghandour K, Ohkawa N, Fung CCA, Asai H, Saitoh Y, Takekawa T. et al. Orchestrated ensemble activities constitute a hippocampal memory engram. Nat Commun. 2019;10:2637. https://doi.org/10.1038/s41467-019-10683-2.
Liu X, Ramirez S, Pang PT, Puryear CB, Govindarajan A, Deisseroth K. et al. Optogenetic stimulation of a hippocampal engram activates fear memory recall. Nature. 2012;484:381–5. https://doi.org/10.1038/nature11028.
Denny CA, Kheirbek MA, Alba EL, Tanaka KF, Brachman RA, Laughman KB. et al. Hippocampal memory traces are differentially modulated by experience, time, and adult neurogenesis. Neuron. 2014;83:189–201. https://doi.org/10.1016/j.neuron.2014.05.018.
Lacagnina AF, Brockway ET, Crovetti CR, Shue F, McCarty MJ, Sattler KP. et al. Distinct hippocampal engrams control extinction and relapse of fear memory. Nat Neurosci. 2019;22:753–61. https://doi.org/10.1038/s41593-019-0361-z.
Cowansage KK, Shuman T, Dillingham BC, Chang A, Golshani P, Mayford M. Direct reactivation of a coherent neocortical memory of context. Neuron. 2014;84:432–41. https://doi.org/10.1016/j.neuron.2014.09.022.
Matos MR, Visser E, Kramvis I, van der Loo RJ, Gebuis T, Zalm R. et al. Memory strength gates the involvement of a CREB-dependent cortical fear engram in remote memory. Nat Commun. 2019;10:2315. https://doi.org/10.1038/s41467-019-10266-1.
Kitamura T, Ogawa SK, Roy DS, Okuyama T, Morrissey MD, Smith LM. et al. Engrams and circuits crucial for systems consolidation of a memory. Science. 2017;356:73–8. https://doi.org/10.1126/science.aam6808.
Sano Y, Shobe JL, Zhou M, Huang S, Shuman T, Cai DJ. et al. CREB Regulates Memory Allocation in the Insular Cortex. Curr Biol. 2014;24:2833–7. https://doi.org/10.1016/j.cub.2014.10.018.
Abe K, Kuroda M, Narumi Y, Kobayashi Y, Itohara S, Furuichi T. et al. Cortico-amygdala interaction determines the insular cortical neurons involved in taste memory retrieval. Mol brain. 2020;13:107. https://doi.org/10.1186/s13041-020-00646-w.
Han JH, Kushner SA, Yiu AP, Hsiang HL, Buch T, Waisman A. et al. Selective erasure of a fear memory. Science. 2009;323:1492–6. https://doi.org/10.1126/science.1164139.
Rashid AJ, Yan C, Mercaldo V, Hsiang HL, Park S, Cole CJ. et al. Competition between engrams influences fear memory formation and recall. Science. 2016;353:383–7. https://doi.org/10.1126/science.aaf0594.
Zhou Y, Won J, Karlsson MG, Zhou M, Rogerson T, Balaji J. et al. CREB regulates excitability and the allocation of memory to subsets of neurons in the amygdala. Nat Neurosci. 2009;12:1438–43. https://doi.org/10.1038/nn.2405.
Kim J, Kwon JT, Kim HS, Josselyn SA, Han JH. Memory recall and modifications by activating neurons with elevated CREB. Nat Neurosci. 2014;17:65–72. https://doi.org/10.1038/nn.3592.
Kim WB, Cho J-H. Encoding of contextual fear memory in hippocampal–amygdala circuit. Nat Commun. 2020;11:1382. https://doi.org/10.1038/s41467-020-15121-2.
Choi DI, Kim J, Lee H, Kim JI, Sung Y, Choi JE. et al. Synaptic correlates of associative fear memory in the lateral amygdala. Neuron. 2021;109:2717–26.e3. https://doi.org/10.1016/j.neuron.2021.07.003.
Yiu AP, Mercaldo V, Yan C, Richards B, Rashid AJ, Hsiang HL. et al. Neurons Are Recruited to a Memory Trace Based on Relative Neuronal Excitability Immediately before Training. Neuron. 2014;83:722–35. https://doi.org/10.1016/j.neuron.2014.07.017.
Ramirez S, Liu X, MacDonald CJ, Moffa A, Zhou J, Redondo RL. et al. Activating positive memory engrams suppresses depression-like behaviour. Nature. 2015;522:335–9. https://doi.org/10.1038/nature14514.
Brebner LS, Ziminski JJ, Margetts-Smith G, Sieburg MC, Reeve HM, Nowotny T. et al. The Emergence of a Stable Neuronal Ensemble from a Wider Pool of Activated Neurons in the Dorsal Medial Prefrontal Cortex during Appetitive Learning in Mice. J Neurosci. 2020;40:395–410. https://doi.org/10.1523/jneurosci.1496-19.2019.
Koya E, Uejima JL, Wihbey KA, Bossert JM, Hope BT, Shaham Y. Role of ventral medial prefrontal cortex in incubation of cocaine craving. Neuropharmacology. 2009;56:177–85. https://doi.org/10.1016/j.neuropharm.2008.04.022.
Vetere G, Tran LM, Moberg S, Steadman PE, Restivo L, Morrison FG, et al. Memory formation in the absence of experience. Nat Neurosci. 2019. https://doi.org/10.1038/s41593-019-0389-0.
Suto N, Laque A, De Ness GL, Wagner GE, Watry D, Kerr T. et al. Distinct memory engrams in the infralimbic cortex of rats control opposing environmental actions on a learned behavior. eLife. 2016;5:e21920. https://doi.org/10.7554/eLife.21920.
Dudai Y. The neurobiology of consolidations, or, how stable is the engram?. Annu Rev Psychol. 2004;55:51–86. https://doi.org/10.1146/annurev.psych.55.090902.142050.
Schacter DL. Constructive memory: past and future. Dialogues Clin Neurosci. 2012;14:7–18.
Shaham Y, Shalev U, Lu L, De Wit H, Stewart J. The reinstatement model of drug relapse: history, methodology and major findings. Psychopharmacology. 2003;168:3–20. https://doi.org/10.1007/s00213-002-1224-x.
Mueller D, Stewart J. Cocaine-induced conditioned place preference: reinstatement by priming injections of cocaine after extinction. Behavioural Brain Res. 2000;115:39–47. https://doi.org/10.1016/S0166-4328(00)00239-4.
Di Ciano P, Everitt BJ. Reinstatement and spontaneous recovery of cocaine-seeking following extinction and different durations of withdrawal. Behavioural Pharmacol. 2002;13:397–405.
Mueller D, Perdikaris D, Stewart J. Persistence and drug-induced reinstatement of a morphine-induced conditioned place preference. Behav Brain Res. 2002;136:389–97. https://doi.org/10.1016/s0166-4328(02)00297-8.
Tye KM, Stuber GD, de Ridder B, Bonci A, Janak PH. Rapid strengthening of thalamo-amygdala synapses mediates cue-reward learning. Nature. 2008;453:1253–7. https://doi.org/10.1038/nature06963.
Hiroi N, White N. The lateral nucleus of the amygdala mediates expression of the amphetamine-produced conditioned place preference. J Neurosci: Off J Soc Neurosci. 1991;11:2107–16. https://doi.org/10.1523/JNEUROSCI.11-07-02107.1991.
Rich MT, Huang YH, Torregrossa MM. Plasticity at Thalamo-amygdala Synapses Regulates Cocaine-Cue Memory Formation and Extinction. Cell Rep. 2019;26:1010–20.e5. https://doi.org/10.1016/j.celrep.2018.12.105.
Shabel SJ, Janak PH. Substantial similarity in amygdala neuronal activity during conditioned appetitive and aversive emotional arousal. Proc Natl Acad Sci USA. 2009;106:15031–6. https://doi.org/10.1073/pnas.0905580106.
Figge DA, Rahman I, Dougherty PJ, Rademacher DJ. Retrieval of contextual memories increases activity-regulated cytoskeleton-associated protein in the amygdala and hippocampus. Brain Struct Funct. 2013;218:1177–96. https://doi.org/10.1007/s00429-012-0453-y.
Berndt A, Lee SY, Wietek J, Ramakrishnan C, Steinberg EE, Rashid AJ. et al. Structural foundations of optogenetics: Determinants of channelrhodopsin ion selectivity. Proc Natl Acad Sci USA. 2016;113:822–9. https://doi.org/10.1073/pnas.1523341113.
Zhang F, Aravanis AM, Adamantidis A, de Lecea L, Deisseroth K. Circuit-breakers: optical technologies for probing neural signals and systems. Nat Rev Neurosci. 2007;8:577–81. https://doi.org/10.1038/nrn2192.
Stahlberg M, Ramakrishnan C, Willig K, Boyden E, Deisseroth K, Dean C. Investigating the feasibility of channelrhodopsin variants for nanoscale optogenetics. Neurophotonics. 2019;6:015007.
Lau JMH, Rashid AJ, Jacob AD, Frankland PW, Schacter DL, Josselyn SA. The role of neuronal excitability, allocation to an engram and memory linking in the behavioral generation of a false memory in mice. Neurobiol Learn Mem. 2020;174:107284. https://doi.org/10.1016/j.nlm.2020.107284.
Carlezon WA Jr., Neve RL. Viral-mediated gene transfer to study the behavioral correlates of CREB function in the nucleus accumbens of rats. Methods Mol Med. 2003;79:331–50.
Han JH, Kushner SA, Yiu AP, Cole CJ, Matynia A, Brown RA. et al. Neuronal competition and selection during memory formation. Science. 2007;316:457–60. https://doi.org/10.1126/science.1139438.
Carlezon WA Jr., Nestler EJ, Neve RL. Herpes simplex virus-mediated gene transfer as a tool for neuropsychiatric research. Crit Rev Neurobiol. 2000;14:47–67.
Neve RL, Neve KA, Nestler EJ, Carlezon WA Jr. Use of herpes virus amplicon vectors to study brain disorders. Biotechniques. 2005;39:381–91.
Barrot M, Olivier JD, Perrotti LI, DiLeone RJ, Berton O, Eisch AJ, et al. CREB activity in the nucleus accumbens shell controls gating of behavioral responses to emotional stimuli. Proc Natl Acad Sci USA. 2002;99:11435–40.
Park A, Jacob AD, Walters BJ, Park S, Rashid AJ, Jung JH. et al. A time-dependent role for the transcription factor CREB in neuronal allocation to an engram underlying a fear memory revealed using a novel in vivo optogenetic tool to modulate CREB function. Neuropsychopharmacology. 2020;45:916–24. https://doi.org/10.1038/s41386-019-0588-0.
Anderson EM, Larson EB, Guzman D, Wissman AM, Neve RL, Nestler EJ. et al. Overexpression of the Histone Dimethyltransferase G9a in Nucleus Accumbens Shell Increases Cocaine Self-Administration, Stress-Induced Reinstatement, and Anxiety. J Neurosci. 2018;38:803–13. https://doi.org/10.1523/jneurosci.1657-17.2017.
Vetere G, Restivo L, Cole CJ, Ross PJ, Ammassari-Teule M, Josselyn SA. et al. Spine growth in the anterior cingulate cortex is necessary for the consolidation of contextual fear memory. Proc Natl Acad Sci USA. 2011;108:8456–60. https://doi.org/10.1073/pnas.1016275108.
Wallace DL, Han MH, Graham DL, Green TA, Vialou V, Iniguez SD. et al. CREB regulation of nucleus accumbens excitability mediates social isolation-induced behavioral deficits. Nat Neurosci. 2009;12:200–9. https://doi.org/10.1038/nn.2257.
Brightwell JJ, Smith CA, Countryman RA, Neve RL, Colombo PJ. Hippocampal overexpression of mutant creb blocks long-term, but not short-term memory for a socially transmitted food preference. Learn Mem. 2005;12:12–7.
Prus AJJJ, Rosecrans JA. Conditioned Place Preference. In: JJ B, editor. Methods of Behavior Analysis in Neuroscience. 2nd edition. Boca Raton (FL): CRC Press; 2009.
Hsiang HL, Epp JR, van den Oever MC, Yan C, Rashid AJ, Insel N. et al. Manipulating a “cocaine engram” in mice. J Neurosci. 2014;34:14115–27. https://doi.org/10.1523/JNEUROSCI.3327-14.2014.
Dong Y, Green T, Saal D, Marie H, Neve R, Nestler EJ, et al. CREB modulates excitability of nucleus accumbens neurons. Nat Neurosci. 2006;9:475–7.
Vesuna S, Kauvar IV, Richman E, Gore F, Oskotsky T, Sava-Segal C. et al. Deep posteromedial cortical rhythm in dissociation. Nature. 2020;586:87–94. https://doi.org/10.1038/s41586-020-2731-9.
Armbruster BN, Li X, Pausch MH, Herlitze S, Roth BL. Evolving the lock to fit the key to create a family of G protein-coupled receptors potently activated by an inert ligand. Proc Natl Acad Sci USA. 2007;104:5163–8. https://doi.org/10.1073/pnas.0700293104.
Nichols CD, Roth BL. Engineered G-protein Coupled Receptors are Powerful Tools to Investigate Biological Processes and Behaviors. Front Mol Neurosci. 2009;2:16. https://doi.org/10.3389/neuro.02.016.2009.
Gale GD, Anagnostaras SG, Godsil BP, Mitchell S, Nozawa T, Sage JR, et al. Role of the basolateral amygdala in the storage of fear memories across the adult lifetime of rats. J Neurosci. 2004;24:3810–5.
Lammel S, Lim BK, Ran C, Huang KW, Betley MJ, Tye KM. et al. Input-specific control of reward and aversion in the ventral tegmental area. Nature. 2012;491:212–7. https://doi.org/10.1038/nature11527.
Britt Jonathan P, Benaliouad F, McDevitt Ross A, Stuber Garret D, Wise Roy A, Bonci A. Synaptic and Behavioral Profile of Multiple Glutamatergic Inputs to the Nucleus Accumbens. Neuron. 2012;76:790–803. https://doi.org/10.1016/j.neuron.2012.09.040.
Otis JM, Dashew KB, Mueller D. Neurobiological dissociation of retrieval and reconsolidation of cocaine-associated memory. J Neurosci. 2013;33:1271–81a. https://doi.org/10.1523/jneurosci.3463-12.2013.
O’Leary TP, Sullivan KE, Wang L, Clements J, Lemire AL, Cembrowski MS. Extensive and spatially variable within-cell-type heterogeneity across the basolateral amygdala. eLife. 2020;9:e59003. https://doi.org/10.7554/eLife.59003.
Lucas EK, Jegarl AM, Morishita H, Clem RL. Multimodal and Site-Specific Plasticity of Amygdala Parvalbumin Interneurons after Fear Learning. Neuron. 2016;91:629–43. https://doi.org/10.1016/j.neuron.2016.06.032.
Pavlov I. Conditioned reflexes. Oxford, England: Oxford University Press; 1927.
Rescorla RA, Heth CD. Reinstatement of fear to an extinguished conditioned stimulus. J Exp Psychol Anim Behav Process. 1975;1:88–96.
Bossert JM, Marchant NJ, Calu DJ, Shaham Y. The reinstatement model of drug relapse: recent neurobiological findings, emerging research topics, and translational research. Psychopharmacology. 2013;229:453–76. https://doi.org/10.1007/s00213-013-3120-y.
Mantsch JR, Baker DA, Funk D, Lê AD, Shaham Y. Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress. Neuropsychopharmacology. 2016;41:335–56. https://doi.org/10.1038/npp.2015.142.
Nygard SK, Hourguettes NJ, Sobczak GG, Carlezon WA, Bruchas MR. Stress-Induced Reinstatement of Nicotine Preference Requires Dynorphin/Kappa Opioid Activity in the Basolateral Amygdala. J Neurosci. 2016;36:9937–48. https://doi.org/10.1523/jneurosci.0953-16.2016.
Chou Y-H, Hor CC, Lee MT, Lee H-J, Guerrini R, Calo G. et al. Stress induces reinstatement of extinguished cocaine conditioned place preference by a sequential signaling via neuropeptide S, orexin, and endocannabinoid. Addiction Biol. 2021;26:e12971. https://doi.org/10.1111/adb.12971.
Funding
This work was supported by NIH and Brain Canada grants to SAJ and PWF, as well as CIHR and NSERC grants (SAJ, PWF, JGH).
Author information
Authors and Affiliations
Contributions
All authors made significant contributions to this work. The project was conceived by SAH, PWF and JGH. AP and HLH acquired the data. ADJ helped acquire and analyse the data. The manuscript was written and revised by all authors. All authors approved the final version of this manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Park, A., Jacob, A.D., Hsiang, HL.(. et al. Formation and fate of an engram in the lateral amygdala supporting a rewarding memory in mice. Neuropsychopharmacol. 48, 724–733 (2023). https://doi.org/10.1038/s41386-022-01472-5
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41386-022-01472-5