Sleep deprivation and memory in Insomnia.pptx

Sleep

1. Sleep Deprivation and Memory How biological factors caused by sleep deprivation can affect memory

2. Background Sleep deprivation: the condition of not having enough sleep A do l e s ce n t s n ee d 9 . 2 5 h o u r s o f s l ee p per night Sleep is linked with cognitive skills relevant in high school

3. Background (cont.) Amy Wolfson and Mary Carskadon (1998) The average amount of sleep for teenagers decreased by around 50 minutes per night from the ages of 13-19 Students academically struggling a v e r a g e d 2 5 mi n u t e s l e ss s l ee p p e r n ig h t than students with good grades

4. Background (cont.) Relational memory, the ability to make and remember associations between objects, is an essential component of mammalian reasoning . In relational memory tasks, it has been shown that periods of offline processing , such as sleep, are critical to making indirect associations . Sleep could be universally relevant—for perceptual learning ( Karni et al. 1994 ), skill learning ( Walker et al. 2002 ), paired-associate learning ( Plihal & Born 1997 ), and maybe all types of learning. 

5. Sleep Memories Declarative memories depend on specific parts of the neocortex , each specializing in certain types of information processing . Plasticity in connections across brain regions, including multiple cortical regions and other brain structures, can be key to consolidation Memories in both categories, declarative and nondeclarative , do not necessarily function in isolation; they can interact with each other and with working memory 

6. Consolidation of Memories Declarative memories depend on specific parts of the neocortex , each specializing in certain types of information processing . Plasticity in connections across brain regions, including multiple cortical regions and other brain structures, can be key to consolidation Memories in both categories, declarative and nondeclarative , do not necessarily function in isolation; they can interact with each other and with working memory 

7. Stabilisation of Memory The idea that memory stabilization is a gradual process that takes place after an initial encoding stage has its roots in the work of  Müller & Pilzecker (1900) .  “Certain physiological processes, which serve to strengthen the associations … [that] continue with increasing intensity for a period of time” (cited in  Lechner et al. 1999 , p. 81). Decades later,  retrograde amnesia  was observed in rodents given an electroconvulsive shock 15 minutes after learning ( Duncan 1949 ). In contrast, memory remained intact when the shocks were delivered 1 hour after learning.

8. Physiology Of Memory Consolidation During Sleep Behavioral studies of  memory consolidation  during sleep have produced ample evidence of superior retrieval of various types of information In rodents, consistent evidence has suggested a causal role for rapid eye movement (REM) sleep in memory consolidation  A prominent account of sleep-based consolidation, sometimes termed the  active systems consolidation hypothesis , suggests that  memory reactivation  in the hippocampus during NREM sleep dictates changes in cortical networks ( Buzsáki 1998 ,  Born et al. 2006 ). 

9. Physiology Of Memory Consolidation During Sleep   Figure 1 . Sharp-wave/ripple complexes (SWRs), found locally in the hippocampus, are nested in the troughs of thalamo -cortical sleep spindles, which, in turn, ride on the peaks (or up-states) of cortical slow oscillations (SOs). Accordingly, consolidation is enabled by a synchronized temporal frame for communication among brain areas ( Diekelmann & Born 2010 ).

10. Physiology Of Memory Consolidation During Sleep

11. Physiology Of Memory Consolidation During Sleep Figure 2  (a) Targeted memory reactivation experiments generally include three phases. In the first phase (pre-sleep), participants acquire some new information. This information is coupled with stimuli that are included either as background context or as part of the learning (e.g., a meow sound paired with the spatial location of a cat image). In the second phase (sleep), these stimuli are unobtrusively presented during sleep. In the third phase (post-sleep), memory is tested after sleep. (b) In the experiment of Rasch et al. (2007), spatial learning of 15 objects, each shown in two locations on a 5 × 6 grid, was accomplished while a rose odor was present. Next, during an overnight sleep session with polysomnographic monitoring, the odor or an odorless vehicle was presented during sleep. Finally, spatial memory was assessed the next morning. The results showed relatively better recall when the odor had been presented during slow-wave sleep compared to when it had not. This memory effect was not observed when odors were presented during rapid eye movement (REM) sleep or when the memory test was one of motor learning instead. (c) In the experiment of Rudoy et al. (2009), spatial learning of 50 objects shown in random locations on a grid was accomplished while sounds were presented. For each object, a matching sound was used. Next, during an afternoon nap with polysomnographic monitoring, half of the sounds were presented at a low intensity. Finally, spatial memory was assessed when participants attempted to place each object at precisely the correct screen location. The results showed relatively better memory performance for objects if corresponding sounds had been presented during slow-wave sleep than if not. Error bars represent standard error of the mean.

12. Biological factors affected by sleep Dopamine Amyloid Plaque Adenosine Sleep affects these factors These factors affect memory

13. Dopamine Dopamine: a neurotransmitter that helps control the brain’s reward and pleasure centers Dopamine compensates for lack of sleep, maintains alertness

14. Dopamine Study by Volkow et. al. to investigate relationship between sleep deprivation and dopamine, and effects of dopamine on cognitive processes Findings: Sleep deprivation increased dopamine, which increased motivation, reward, alertness However, increasing dopamine also increased feelings of fatigue, impaired performance on cognitive tasks

15. Dopamine Influence of Dopamine (biological factor) on memory (cognitive process) Sleep deprivation increased dopamine, w h ich w e a k e n e d m e mo r y p e r f o r ma n ce

16. Amyloid Plaques Plaques consist of amyloid deposits surrounded by a web of astrocytic processes, swollen neurites, and neuron terminals; seen in the cerebral cortex in Alzheimer's disease. There is a relationship between amyloid plaques and memory

17. Amyloid Plaques Study by Yo-El Ju to investigate the relationship between sleep deprivation and amyloid plaques affecting memory Findings: People who woke up more than 5 t im e s a n ig h t w e r e mo r e l i k e l y t o h a v e amyloid plaque build-up compared to people who didn’t

18. Amyloid Plaques There is a correlation between disrupted sleep and amyloid plaques A cause-effect relationship can’t be determined People with amyloid plaque build-up are more likely t o h a v e A l z h e im e r ’ s dis e a s e Disrupted sleep leads to amyloid plaque build-up, which leads to higher likelihood of memory loss

19. Adenosine Nucleoside Adenosine: an inhibitory neurotransmitter associated with memory Found in the hippocampus

20. Adenosine S t u dy c o n du ct e d b y T e d A be l e t . a l . t o be tt e r understand the role of nucleoside adenosine F i n di n g s : S l ee p -d ep r i v e d mice w i t h a d e n o s i n e blocked using pharmacology or not produced due to genetic engineering had no memory impairment, and did not act sleep deprived Control group of mice (with adenosine not blocked) had memory impairment, acted sleep deprived

21. Adenosine Memory impairment: symptom of sleep deprivation Mice with blocked adenosine but sleep d e p r i v a t io n did n o t h a v e m e mo r y impairment Biological factors affect how sleep deprivation affects cognitive processes

22. Conclusion Interactive relationship between cognition and physiology Both can be affected by outside factors Biological factors affected by sleep deprivation Cognition affected by biological factors

23. S o u r ce s http://www.sciencedaily.com/releases/ 2008/08/080819213033.htm http://www.sciencedaily.com/releases/ 2012/02/120214171036.htm http://www.sciencedaily.com/releases / 2011/05/110517171118.htm https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6879745 / https://www.annualreviews.org/doi/10.1146/annurev-psych-010419-050815