The dynamic nature of systems consolidation: Stress during learning as a switch guiding the rate of the hippocampal dependency and memory quality.
Memory fades over time, becoming more schematic or abstract. The loss of contextual detail in memory may reflect a time-dependent change in the brain structures supporting memory. It has been well established that contextual fear memory relies on the hippocampus for expression shortly after learning, but it becomes hippocampus-independent at a later time point, a process called systems consolidation. This time-dependent process correlates with the loss of memory precision. Here, we investigated whether training intensity predicts the gradual decay of hippocampal dependency to retrieve memory, and the quality of the contextual memory representation over time. We have found that training intensity modulates the progressive decay of hippocampal dependency and memory precision. Strong training intensity accelerates systems consolidation and memory generalization in a remarkable timeframe match. The mechanisms underpinning such process are triggered by glucocorticoid and noradrenaline released during training. These results suggest that the stress levels during emotional learning act as a switch, determining the fate of memory quality. Moderate stress will create a detailed memory, whereas a highly stressful training will develop a generic gist-like memory.
Laboratório De Neurobiologia Da Memória, Porto Alegre, 91.501-970, Brazil.|Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande Do Sul, Porto Alegre, 90.046-900, Brazil.
Lizeth K
LK
Pedraza
Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande Do Sul, Porto Alegre, 90.046-900, Brazil.|Laboratório De Psicobiologia E Neurocomputação, Biophysics Department, Biosciences Institute, Porto Alegre, 91.501-970, Brazil.
Rodrigo O
RO
Sierra
Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande Do Sul, Porto Alegre, 90.046-900, Brazil.|Laboratório De Psicobiologia E Neurocomputação, Biophysics Department, Biosciences Institute, Porto Alegre, 91.501-970, Brazil.
Flávia Z
FZ
Boos
Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande Do Sul, Porto Alegre, 90.046-900, Brazil.|Laboratório De Psicobiologia E Neurocomputação, Biophysics Department, Biosciences Institute, Porto Alegre, 91.501-970, Brazil.
Josué
J
Haubrich
Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande Do Sul, Porto Alegre, 90.046-900, Brazil.|Laboratório De Psicobiologia E Neurocomputação, Biophysics Department, Biosciences Institute, Porto Alegre, 91.501-970, Brazil.
Jorge A
JA
Quillfeldt
Laboratório De Neurobiologia Da Memória, Porto Alegre, 91.501-970, Brazil.|Graduate Program in Neuroscience, Institute of Health Sciences, Federal University of Rio Grande Do Sul, Porto Alegre, 90.046-900, Brazil.
Lucas de Oliveira
Lde O
Alvares
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001095:Arachidonic Acids / Q000494:pharmacology; D055592:Biophysical Phenomena / Q000187:drug effects / Q000502:physiology*; D001703:Biophysics; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004558:Electric Stimulation; D063388:Endocannabinoids / Q000494:pharmacology; D005260:Female; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology*; D066298:In Vitro Techniques; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D009474:Neurons / Q000145:classification / Q000502:physiology*; D018408:Patch-Clamp Techniques; D053284:Polyunsaturated Alkamides / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D001095:Arachidonic Acids; D002121:Calcium Channel Blockers; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D026941:Sodium Channel Blockers; D013779:Tetrodotoxin; D002118:Calcium; C078814:anandamide
consolidation; generalization; hippocampus; memory; stress