Why healthy sleep is important for learning, memory, cognitive health, and dreams.

By Ian Wilson (2021) https://www.dreamingforgamers.com/ In 1990, a memory-forming protein was discovered by Alfonso Represa[1] called neurogranin. Since its discovery, research into neurogranin expression was found to play a role in how the brain forms memory[2]. Neurogranin is a postsynaptic neural protein, that is found in high quantities in the cortex, hippocampus, striatum, and amygdala. Neurogranin is a biomarker in Alzheimer's disease and cognitive impairment.[3] A decrease in Ng in blood plasma exomes and an increased level appears in cerebral spinal fluid CFS. Sleep deprivation[4] also causes a significant reduction in Ng levels by as much as 40%[5]. It has been known since 2013 in sleep apnea studies that sleep deprivation impairs long-term memory[6] And total sleep deprivation leads to serious health issues and even death. [7] REM impairment and poor sleep can impact learning development as much as 40%[8] Understanding the benefits of a good night's sleep and why we should strive towards a baseline average of 7-8 hours of uninterrupted sleep as an optimal marker for cognitive health stems from other important neuroscientific discoveries regarding how REM sleep is important for cognitive development[9] and neuronal development and maintenance[10]. Studies on the hippocampus during sleep plays a role in long-term memory consolidation[11] and learning development[12] during a process known as hippocampal replay. In addition to learning development and memory consolidation. Hippocamplay-replay has also been observed with memory retrieval[13]. Hippocampal-replay and memory consolidation is associated with how dreams are formed in the brain [14]. Dreaming is not exclusive to humans and is a function of the mammalian brain.[15] Dreaming is observed in REM[16] and NREM[17] sleep. On average a human produces 3-5[18] dreams each night as part of the REM/NREM sleep cycles. Why dream recall is not always present in certain people has been linked to white-matter density in the medial prefrontal cortex[19] and dream recall declines with age[20] with a 50% drop[20] in adults after the brain develops[21] with a rapid decline towards the age of 60+. Neural-pathway development and density in the medial prefrontal cortex are indicative that the role of dream recall is a cognitive function and can be viewed as a developmental skill[22]. Routine efforts to recall dreams can improve impaired development. As a cognitive skill, actively recalling dreams will help promote neural-pathway development and this is noted in people who have had a prolonged loss in dream recall spanning years and even decades who begin to recall dreams in later years when learning how to recall dreams. If you have developmental issues around dream recall, here are some methods for dream recall that may help with improving memory if dreaming is of any interest. Unless there are lesions or damage to the medial-prefrontal cortex, rehabilitating memory loss with dreams is more an issue of effort and practice over time to get the proper function of dream-recall. 1.) Have a healthy amount of sleep. 2.) If you drink coffee, alcohol, use weed or other drugs[23]. Going to sleep while still under the influence can impede REM sleep impairing learning and neuronal development and can affect recall. It's recommended at a minimum to let stimulants wear off before sleep, or limit the use or remove them together. 3.) Dream memory resides in short-term memory. The hippocampus becomes active again after two minutes upon waking. It's recommended not to immediately exit the bed and try to remember. Retain the memories and review while the hippocampus becomes active again for at least 2-5 minutes then proceed to write keywords of any dream fragment, then flush out the memories. Having keywords help as we can lose 90% of our recall in 10 minutes after waking.[24] These can help trigger a memory from amnesiac memory loss. 4.) Use a soft alarm like a quiet to loud melody or a light alarm. Loud alarms often cause instant dream memory loss and people who often ease themselves awake find dream recall more accessible. 5.) For any developmental skill, routine is important so work on dream-recall over a period of time and expect slow gradual improvements over a period of weeks. 6.) Why dream journals are helpful is they force repeat reviews of dreams which will help stimulate the medial-prefrontal cortex helping stimulate those neural pathways that function for dream memory. References: [1] Represa, Alfonso & Deloulme, Jean Christophe & Sensenbrenner, M & Ben-Ari, Yehezkel & Baudier, Jacques. (1991). Neurogranin: Immunocytochemical localization of a brain-specific protein kinase C substrate. The Journal of neuroscience: the official journal of the Society for Neuroscience. 10. 3782-92. 10.1523/JNEUROSCI.10-12-03782.1990. [2] Jones KJ, Templet S, Zemoura K, Kuzniewska B, Pena FX, Hwang H, Lei DJ, Haensgen H, Nguyen S, Saenz C, Lewis M, Dziembowska M, Xu W. Rapid, experience-dependent translation of neurogranin enables memory encoding. Proc Natl Acad Sci U S A. 2018 Jun 19;115(25):E5805-E5814. doi: 10.1073/pnas.1716750115. Epub 2018 Jun 7. PMID: 29880715; PMCID: PMC6016824. [3] Liu W, Lin H, He X, Chen L, Dai Y, Jia W, Xue X, Tao J, Chen L. Neurogranin as a cognitive biomarker in cerebrospinal fluid and blood exosomes for Alzheimer's disease and mild cognitive impairment. Transl Psychiatry. 2020 Apr 29;10(1):125. doi: 10.1038/s41398-020-0801-2. PMID: 32350238; PMCID: PMC7190828. [4]Martin Neuner-Jehle, Thomas A. Rhyner, Alexander A. Borbély, Sleep deprivation differentially alters the mRNA and protein levels of neurogranin in rat brain, Brain Research, Volume 685, Issues 1–2, 1995, Pages 143-153,ISSN 0006-8993 [5] Díez-Guerra, F.J. (2010), Neurogranin, a link between calcium/calmodulin and protein kinase C signaling in synaptic plasticity. IUBMB Life, 62: 597-606. https://doi.org/10.1002/iub.357 [6] Mander, B., Rao, V., Lu, B. et al. Prefrontal atrophy, disrupted NREM slow waves and impaired hippocampal-dependent memory in aging. Nat Neurosci 16, 357–364 (2013). https://doi.org/10.1038/nn.3324 [7] Everson CA, Bergmann BM, Rechtschaffen A. Sleep deprivation in the rat: III. Total sleep deprivation. Sleep. 1989 Feb;12(1):13-21. doi: 10.1093/sleep/12.1.13. PMID: 2928622. [8] Pacheco, Danielle & Reham, Anis (2020) Memory and Sleep. Sleep Foundation https://www.sleepfoundation.org/how-sleep-works/memory-and-sleep [9] Jiang F. Sleep and Early Brain Development. Ann Nutr Metab. 2019;75 Suppl 1:44-54. doi: 10.1159/000508055. Epub 2020 Jun 19. PMID: 32564032. [10] Wolfe K, Ralls FM. Rapid eye movement sleep and neuronal development. Curr Opin Pulm Med. 2019 Nov;25(6):555-560. doi: 10.1097/MCP.0000000000000622. PMID: 31503214. [11] Ólafsdóttir HF, Bush D, Barry C. The Role of Hippocampal Replay in Memory and Planning. Curr Biol. 2018;28(1):R37-R50. doi:10.1016/j.cub.2017.10.073 [12] Jean-Baptiste Eichenlaub, Beata Jarosiewicz, Jad Saab, Brian Franco, Jessica Kelemen, Eric Halgren, Leigh R. Hochberg, Sydney S. Cash, Replay of Learned Neural Firing Sequences during Rest in Human Motor Cortex, Cell Reports, Volume 31, Issue 5, 2020, 107581, ISSN 2211-1247, https://doi.org/10.1016/j.celrep.2020.107581. (https://www.sciencedirect.com/science/article/pii/S2211124720305301) [13] Pfeiffer BE. The content of hippocampal "replay". Hippocampus. 2020 Jan;30(1):6-18. doi: 10.1002/hipo.22824. Epub 2018 Jan 10. PMID: 29266510; PMCID: PMC7027863. [14] Payne JD, Nadel L. Sleep, dreams, and memory consolidation: the role of the stress hormone cortisol. Learn Mem. 2004;11(6):671-678. doi:10.1101/lm.77104 [15] Manger PR, Siegel JM. Do all mammals dream? J Comp Neurol. 2020 Dec 1;528(17):3198-3204. doi: 10.1002/cne.24860. Epub 2020 Jan 29. PMID: 31960424; PMCID: PMC8211436. [16] Nir Y, Tononi G. Dreaming and the brain: from phenomenology to neurophysiology. Trends Cogn Sci. 2010;14(2):88-100. doi:10.1016/j.tics.2009.12.001 [17] Jaakko O. Nieminen, Olivia Gosseries, Marcello Massimini, Elyana Saad, Andrew D. Sheldon, Melanie Boly, Francesca Siclari, Bradley R. Postle, Giulio Tononi. Consciousness and cortical responsiveness: a within-state study during non-rapid eye movement sleep. Scientific Reports, 2016; 6: 30932 DOI: 10.1038/srep30932 [18] Siclari, Francesca & Bernardi, Giulio & Cataldi, Jacinthe & Tononi, Giulio Dreaming in NREM Sleep: A High-Density EEG Study of Slow Waves and Spindles (2018) 10.1523/JNEUROSCI.0855-18.2018 The Journal of Neuroscience 9175-9185 [19] Vallat R, Eichenlaub JB, Nicolas A, Ruby P. Dream Recall Frequency Is Associated With Medial Prefrontal Cortex White-Matter Density. Front Psychol. 2018 Sep 27;9:1856. doi: 10.3389/fpsyg.2018.01856. PMID: 30319519; PMCID: PMC6171441. [20] Nielsen T. Variations in dream recall frequency and dream theme diversity by age and sex. Front Neurol. 2012;3:106. Published 2012 Jul 4. doi:10.3389/fneur.2012.00106 [21] Arain M, Haque M, Johal L, et al. Maturation of the adolescent brain. Neuropsychiatr Dis Treat. 2013;9:449-461. doi:10.2147/NDT.S39776 [22] Emily R. Oby, Matthew D. Golub, Jay A. Hennig, Alan D. Degenhart, Elizabeth C. Tyler-Kabara, Byron M. Yu, Steven M. Chase, Aaron P. Batista. New neural activity patterns emerge with long-term learning. Proceedings of the National Academy of Sciences, 2019; 201820296 DOI: 10.1073/pnas.1820296116 [23] Sharma, Shridhar & A, Prasad. (2015). DRUG INDUCED REM DISORDERS. Journal of Sleep Medicine & Disorders. 2. 1021. [24] Lee Ann Obringer & Yves Jeffcoat. How Dreams Work (2021) https://science.howstuffworks.com/life/inside-the-mind/human-brain/dream4.htm