Declarative memories

SWS/SWA, in particular, may play an important role in somatic and cognitive restoration, including the consolidation of certain forms of procedural and declarative memory. A substantial diminution in the amount of SWS/SWA occurs across the human lifespan. This decline is beginning already in adolescence and middle-aged adults have only 25% of the SWS observed in young adults, whereas the elderly have almost none. While the clinical importance of these phenomena is unknown, it is reasonable to speculate that they may be related to the increase of sleep complaints associated with aging. 

LTP has been shown in many parts of the brain but it has been most extensively studied in the hippocampus, a phy-logenetically old part of the cerebral cortex that in humans is embedded in the temporal horn and in rats and rabbits lies beneath the parietal and temporal neocortex (Fig. 15-3A). The hippocampus is essential for (declarative) memory formation in rats the role of hippocampus in acquisition of spatial information has been studied in... 

Declarative memory vs. procedural memory. Based on the types of memory selectively affected in such amnesic patients, memory can be divided into two major classes declarative memory and procedural memory. 

Declarative memory, also termed explicit memory, is memory of places, events, facts and people, and is dependent on the temporal lobe system. Retrieval of these memories requires conscious recollection. This type of memory tends to form easily and be forgotten easily. 

Short-term memory vs. long-term memory. The classification of memories into declarative memory and... 

The proposed neurogenesis-memory clearance hypothesis is attractive because addition and removal of adult-born neurons in local network architecture could gradually destabilize the stored memory traces. Also, adult-generated neurons within the dentate gyrus, the upstream location in the hippocampus, potentially can amplify the destabilization effects. Coincidently, these newborn neurons are short-lived, typically with a life-span of three weeks in rodents [40], which seems to correlate well with the duration of hippocampal dependence of declarative memories. 

Bucan M, Abel T (2002) The mouse genetics meets behaviour. Nat Rev Genet 3 114-123 Cahill L, McGaugh JL (1998) Mechanisms of emotional arousal and lasting declarative memory. Trends Neurosci 21 294-299... 

Bremner JD, VythUingam M, Vermetten E, Southwick SM, McGlashan T, Staib LH, Soufer R, Charney DS (2003) Neural correlates of declarative memory for emotionally valenced words in women with posttraumatic stress disorder related to early childhood sexual abuse. Biol Psychiatry 53 879-889... 

In a double blind, randomized, placebo-controlled trial 39 patients (mean age 44 years, 8 men) with allergies or pulmonary or rheumatological illnesses who were taking prednisone (mean dose 40 mg/day) were randomized to either phcnytoin (300 mg/day) or placebo for 7 days (96). Those who took phenytoin had significantly smaller increases in a mania self-report scale. There was no effect on memory. Thus, phcnytoin blocked the hypomanic effects of prednisone, but not the effects on declarative memory. 

Brown ES, Stuard G, Liggin JD, Hukovic N, Frol A, Dhanani N, Khan DA, Jeffress J, Larkin GL, McEwen BS, Rosenblatt R, Mageto Y, Hanczyc M, Cullum CM. Effect of phenytoin on mood and declarative memory during prescription corticosteroid therapy. Biol Psychiatry 2005 57(5) 543-8. 

Why is dreaming so limited by impoverishment in recall In particular, why do we lose the capacity to recou nt actively declarative memories (memories that are learned quickly and consciously) and gain the capacity to activate remote ones ... 

As declarative memory (memory that results from conscious awareness and associations) depends so strongly on an intact hippocampus, are our daytime experiences temporarily stored there for further processing ... 

Are bits of declarative memory, but not entire scenarios, transferred out of the hippocampus when the brain is reactivated in REM sleep ... 

But I do need a conscious declarative memory system too, and it needs to be ample, accurate, and updatable, especially around issues of orientation. 

My dreams reveal how procedural and declarative memory systems intersect and interact in sleep. They always show respect for the universal aspects of my behavioural repertoire and they treat the orientational details in a relatively cavalier fashion in order to achieve efficiency - they trade precise historical accuracy for global emotional associativity. In other words, my dreams reveal how little detail of my daily experience - but how much of the emotional salience - gets mapped on to my procedural repertoire. After all, most of the details are redundant anyway. I already know who I am, who my key people are, where I live and work, and what I have done, am doing, and intend to do in the future. 

Thought (item 6) and orientation (item 7) are both impaired by disablement of the aminergic systems and regional deactivation of the global and local memory systems of the brain. We want to know more about why declarative memories, which are presumably stored in the hippocampus and then moved out to the cortex, are so seldom available to dream consciousness. Clearly, all cognitive functions that depend on memory, except possibly emotional salience, are weakened in REM sleep. Dream consciousness is therefore both a poor analyser and a poor organizer of its content. Hyperassociativity and emotional salience are the rules that govern... 

Eichenbaum H. 2004. Hippocampus Cognitive processes and neural representations that underlie declarative memory. 

Weiss AP, Heckers S. 2001. Neuroimaging of declarative memory in schizophrenia. Scand J Psychol 42 239-250. 

There were moderate but significant improvements in neurocognition (including executive function, working memory, and declarative memory) in a randomized, double -blind, 8-week study in 52 patients with schizophrenia assigned either to olanzapine (10-20 mg/day n = 18) or amisulpride (400-800 mg/day n = 18) (11). Of 16 dropouts, six were due to adverse events olanzapine—sedation (n = 2) and increased transaminases (n = 1) amisulpride—rash, extrapyramidal symptoms, and galactorrhea (n — 1 each). 

Cognitive performance and plasma cortisol were evaluated before and until 10 days after drug administration. Cortisol produced a dose-related reversible reduction in verbal declarative memory without effects on nonverbal memory, sustained or selective attention, or executive function. Exposure to cortisol at doses and plasma concentrations associated with physical and psychological stress in humans can reversibly reduce some elements of memory performance. 

Chronic glucocorticoid exposure is associated with reduced size of the hippocampus, resulting in impaired declarative memory. In 52 renal transplant recipients (mean age 45 years, 34 men and 18 women) taking prednisone (100 mg/day for 3 days followed by 10 mg/day for as long as needed mean dose 11 mg/day) there was a major reduction in immediate recall but not delayed recall (199). However, there was a significant correlation between mean prednisone dose and delayed recall. 

Listen, stranger this was myself this was 1. (W. Faulkner, very last sentence in The Jail ) Alzheimer s disease has prevalence estimates of approximately 10% in individuals over age 65 and 30% in individuals over age 85 in the United States. Clinically AD presents as a progressive deterioration of selective cognitive domains, with initial symptoms indicating a decline in memory function, particularly a loss of episodic memory, which is considered a subcategory of declarative memory. But it is also well documented that a large number of elderly people have poorer memory performances, with prevalence of up to 40% in individuals over 60 years (Hanninen et al.,... 

Cohen, O., Reichenberg, A., Perry, C., Ginzberg, D., Pollmacher, T., Soreq, H., Yirmiya, R. (2003). Endotoxin-induced changes in human working and declarative memory associate with cleavage of plasma readthrough acetylcholinesterase. J. Mol. Neurosci. 21 199-212. 

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