Consolidation of memory traces in cultured cortical networks requires low cholinergic tone, synchronized activity and high network excitability
| Autor: | Martina Lamberti, Joost le Feber, Gerco Hassink, Richard J. A. van Wezel, Inês Dias, Marloes Levers |
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| Přispěvatelé: | TechMed Centre, Clinical Neurophysiology, Biomedical Signals and Systems |
| Rok vydání: | 2021 |
| Předmět: |
0206 medical engineering
Cholinergic Agents Biomedical Engineering Biophysics UT-Hybrid-D Hippocampus Stimulation 02 engineering and technology Engram Stimulus (physiology) Sleep Slow-Wave 03 medical and health sciences Cellular and Molecular Neuroscience 0302 clinical medicine Rhythm Memory cholinergic tone medicine Animals electrical stimulation Neurons Neocortex dissociated cortical neurons Chemistry 020601 biomedical engineering Rats systems consolidation medicine.anatomical_structure memory consolidation Cholinergic Memory consolidation Neuroscience 030217 neurology & neurosurgery network excitability synchronized activity |
| Zdroj: | Journal of Neural Engineering, 18, 4, pp. 1-16 Journal of Neural Engineering, 18, 1-16 Journal of neural engineering, 18(4):046051. Institute of Physics (IOP) |
| ISSN: | 1741-2560 |
| Popis: | In systems consolidation, encoded memories are replayed by the hippocampus during slow-wave sleep (SWS), and permanently stored in the neocortex. Declarative memory consolidation is believed to benefit from the oscillatory rhythms and low cholinergic tone observed in this sleep stage, but underlying mechanisms remain unclear. To clarify the role of cholinergic modulation and synchronized activity in memory consolidation, we applied repeated electrical stimulation in mature cultures of dissociated rat cortical neurons with high or low cholinergic tone, mimicking the cue replay observed during systems consolidation under distinct cholinergic concentrations. In the absence of cholinergic input, these cultures display activity patterns hallmarked by network bursts, synchronized events reminiscent of the low frequency oscillations observed during SWS. They display stable activity and connectivity, which mutually interact and achieve an equilibrium. Electrical stimulation reforms the equilibrium to include the stimulus response, a phenomenon interpreted as memory trace formation. Without cholinergic input, activity was burst-dominated. First application of a stimulus induced significant connectivity changes, while subsequent repetition no longer affected connectivity. Presenting a second stimulus at a different electrode had the same effect, whereas returning to the initial stimuli did not induce further connectivity alterations, indicating that the second stimulus did not erase the ‘memory trace’ of the first. Distinctively, cultures with high cholinergic tone displayed reduced network excitability and dispersed firing, and electrical stimulation did not induce significant connectivity changes. We conclude that low cholinergic tone facilitates memory formation and consolidation, possibly through enhanced network excitability. Network bursts or SWS oscillations may merely reflect high network excitability. |
| Databáze: | OpenAIRE |
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