Neurobiology of Memory Reconsolidation

Neurobiology of Memory Reconsolidation What is the current understanding of the neurobiology of memory reconsolidation and how will impact psychology. Abstract This essay is focusing on the neurobiology of memory reconsolidation, specifically on the molecular mechanisms of LTP and reconsolidation, and the crucial role synaptic plasticity plays in fear conditioning and its resultant implication for psychopathology specifically Posttraumatic stress disorder This essay is focusing on current understanding of the neurobiology of memory reconsolidation, specifically on the molecular mechanisms of LTP and reconsolidation, and its resultant implication for psychopathology specifically promising research using propranolol and d-cycloserine as a treatment of post-traumatic stress disorder. Memory consolidationis the process by which memories are stabilised after being acquired. Consolidation studies have traditionally focused on the hippocampus andsystems consolidation, whereshort term memories become long term memories and independent of thehippocampus over time (Pinel, 2011). The more recently discovered process of consolidation is synaptic consolidation, which occurs within the first few hours after learning, and requires protein synthesis and gene transcription (Pinel, 2011). Long term memories were once considered to be stable, but within the last decade, the discovery of reconsolidation, the process in which stored memories can be retrieved and held in labile short-term memory, has changed theory and research on memory (Pinel, 2011). The neurobiological process of synaptic memory consolidation is thought to be long-term potentiation (LTP), which is the prolonged strengthening of the synapse with increased signalling between two neurons (Sacktor, 2012). The model of LTP and synaptic consolidation, as first theorised by Hebb (Pinel, 2011), suggests that changes in membrane potential and alterations of synapticprotein synthesis such as activating Phosporylated Mitogen Activated Protein Kinase (MAPK),are achieved through activatingintracellular transduction cascades, such as glutamate activating the NMDA receptor so that calcium ions can enter the neuron. These molecular cascades triggertranscription factors such as CREBthat lead to changes ingene expression through RNA synthesis (Pinel, 2011). The result of the gene expression is the lasting structural remodelling of synapses. This complex process of the molecular cascade, expression and process of transcription factors, is susceptible to disruptions in the short ti me period immediately following memory induction (Nader, Schafe LeDoux, 2000a). The potential for memory to be distrupted during consolidation has been extensively researched using pharmacology and trauma. For example, in experiments on Pavlovian fear conditioning in rats, LTP and fear conditioning were blocked when NMDA-receptorantagonistswere administered (Nader et al, 2000b). This process ofLTPis regarded as a contributing factor tosynaptic plasticityand in the growth ofsynaptic strength, and is thought to underlie memory formation, as it affects memory when disrupted. It was previously thought that even though this long process of consolidation could be disrupted, once a memory was consolidated it could not be disrupted. This classic view has been revised over the last 15 years, with extensive research showing that consolidated memories, once retrieved, revert to a labile state where they can be disrupted and undergo another consolidation process, called reconsolidation. (Shwabe, 2014). Reconsolidation was first hypothesised after studies were done using electroconvulsive shock therapy to disrupt consolidated fear memory (Tronson Taylor, 2007). Nader’s (2000a) landmark research using Pavlovianfear conditioningon rats found that a consolidated fear memory can return to alabilestate, when the amygdalais infused with theprotein synthesis inhibitor anisomycin. Subsequent studies have also shown that post-retrieval treatment with protein synthesis inhibitors can lead to an amnestic state (Shwabe, 2014). It has been concluded therefore that cons olidated fear memory, when reactivated, enters a changeable state that requires de novo protein synthesisfor new consolidation or reconsolidation of the old memory (Shwabe, 2014). Since these breakthrough studies many more have found evidence supporting reconsolidation, and have explored its processes and implications. Reconsolidation research over the last decade has demonstrated that some, but not all memories can be strengthened, weakened, or updated thus providing an opportunity to modify some long term memories (Shwabe, 2014). This very limited essay will focus on a few of the important animal and human studies related to fear memory and reconsolidation theory and its implications for psychology. Fear conditioning, fear memory and extinction learning experiments, often use manipulations of theamygdala, due to its involvement in the encoding and memory of significant emotional experiences (Agren et al, 2012). Most of the research on reconsolidation has been done on animals, one of the first studies of human fear memory consolidation was by Kindt in 2009 in which healthy participants were first fear-conditioned and the fear was reactivated by a single presentation of a conditioned stimulus 24 hours later. Shortly before memory reactivation, participants received the beta-adrenergic receptor blocker propranolol during the proposed reconsolidation window, which resulted in substantial weakening of the behavioural fear response and the return of fear memory. Research by Schiller (2010) also explored fear memory activation and update mechanisms and extinction learning, and found the ventromedial prefrontal cortex (vmPFC) plays an important role (Schiller, 2013). Agren et al (2012) also demonstrated fear memory trace erasure in the amygdala of humans using behavioural manipulations. Using functional brain imaging, Agren and colleagues (2012) found that when reconsolidation was disrupted through extinction training, the fear memory was significantly weakened and the memory trace was erased in the amygdala. Additional important recent research providing support for memory updating used Pavlovian fear conditioning manipulations and micro density heat map measures of fear memory on the lateral amygdala of rats, and found that the memory recapitulated not only in the same location but in new areas during reconsolidation (Bergstrom, McDonald, Dey, Tang, Selwyn Johnson, 2013). These, and many more important studies using different experimental manipulations, suggest that memory is labile and updated after reactivation, and that more or less the same areas are recruited for reconsolidation that are involved in initial memory formation. The potential ability to modify established emotional memories through the processes of memory updating, reconsolidationand extinction of conditioned fear memories has important implications for the treatment of many mental disorders, including anxiety disorders, such as post-traumatic stress disorder. Posttraumatic stress disorder is classified as ananxiety disorderin the DSM iV, characteristic symptoms of PTSD are strong traumatic memories that are continuously retrieved in an intrusive manner, causing re-experiencing of the original trauma (Schwabe, 2014).Research is focusing on testing pharmacological treatments and behavioural interventions that target memory reconsolidation in PTSD populations. One drug being researched in neurobiology for the treatment of PTSD is propranolol, the b-adrenergic receptor antagonist that has effects on protein synthesis. The idea that propranolol could be a useful treatment in PTSD stemmed from studies showing that this drug can disrupt the reconsolidation of fear conditioning in animal models and humans (Kindt, 2009). There is some evidence of success with propranolol, such as in pilot studies by Pitman (2002) and Vaiva (2003) which found that immediate treatment with propranolol decreases posttraumatic stress disorder two months after trauma. In recent experiments using propranolol, patients with chronic PTSD were asked to prepare a written script of their personal traumatic experience that caused the PTSD. Each patient then received either propranolol or a placebo (Brunet et al, 2008). One week later, all patients underwent a procedure where there physiological arousal was tested as the script was read. The results showed that psychophysiological responding was significantly lower in patients who had received propranolol a week earlier than in patients who were administered a placebo. These findings were replicated and extended in three open-label studies where PTSD symptoms were significantly lower than at pretreatment (Brunet et al, 2011). In these promising studies on the effect of post-retrieval propranolol in chronic PTSD it is ambiguous as to whether the benefits were from propranolol enhancement or the psychological intervention; And whether propranolol enhanced extinction consolidation or blocked memory reconsoli dation. (de Kleine et al, 2013). Some of these studies also lacked the appropriate control groups that would be required to conclude that the observed effects are due to changes in memory reconsolidation, however, these findings suggest that postretrieval manipulations with propranolol might be a promising tool in the treatment of PTSD, even when the trauma is decades old. d-cycloserine (DCS) is another pharmacological intervention being recently researched in reconsolidation and PTSD due to it being a partial NMDA receptor agonist and extinction enhancer (De Kliene, 2014). Research on using exposure therapy with DCS for PTSD suggests that it could be promising (De Kliene, 2014). Exposure therapy is established as an effective form of fear extinction training in PTSD through the repeated exposure of the trauma memory, and its emotional processing (De Kliene, 2014). De Kleine, Hendriks, Kusters, Broekman, and van Minnen (2012) investigated the effect of DCS on exposure therapy on a female civilian population and found no overall enhancement effects, but a stronger treatment response. However, a second study on a male veteran population found a significant enhancement (Litz et al, 2012). Some criticisms of these studies were the possibility that DCS might have undesirable effects when there is no in session fear extinction, and the need for more research and better administration of the drug (De Kleine, 2014). Sheeringa (2014) researched the effect of d-cycloserine with cognitive behaviour therapy on pediatric posttraumatic stress using a randomized placebo-controlled d-cycloserine. So far, DCS has only shown as extinction effect when used with behavioural training such as exposure therapy and CBT. This study did not show a greater effect on reducing PTSD symptoms, but did show preliminary evidence for improving attention of participants. Another promising study currently in press looked at whether DCS enhanced psychotherapy when used with virtual reality trauma exposure therapy (Difede, 2014). The pilot trial was randomized, placebo-controlled, and double-blind and found significantly greater PTSD remission rates for DCS group, with larger between groups effect sizes (Difede, 2014). Understanding the processes of reconsolidation and the crucial role synaptic plasticity plays in fear conditioning does have exciting and important implication for psychopathology specifically PTSD. There are still barriers and boundary conditions to be understood and overcome for example, memory age and strength. In Posttraumatic stress disorder, unwanted memories need to be retrieved and destabilized before they can be modified during reconsolidation. One of the barriers particular to PTSD is that researchers have proposed that younger and weaker memories are more likely to be modified after reconsolidation than older and stronger memories which are less likely to be modified (Wihchet, 2011). Further boundary conditions highlighted by Shwabe at al (2014) is the context in which the reactivation takes place, and the presence of new information at reactivation of the memories. Therefore, more research is needed to understand exactly when memories do and do not undergo reconsolidation in order to use reconsolidation as a treatment for disorders such as PTSD.

Music Appreciation Text Questions Essay

Please complete the following questions. It is important that you use full sentences and present the questions and answers when you submit your work. Submit the work as a file attachment. This means you complete all work in a word processing document (e.g., Microsoft Word) and attach the file using the dropbox tool. Use the Unit 3: Text Questions dropbox basket. The answers to the Review & Critical Thinking questions are worth 10 points. Review Questions 1. What is the Hurrian song? Why is it important?The Hurrian Song is a collection of music inscribed on cuneiform on clay tablets. Its important because it is one of the first times Hymns were written down. 2. What is the Natya Shastra? Why is it important? Natya Shastra is a writing on the performing arts, dancing, and stage performance. This is important because it gives quite a detailed information on the types of instruments that was used at the time and was popular. 3. Who were troubadours? What was their music like?Troubadours were traveling poet musicians who traveled from place to place singing and performing for the nobility. The songs that were sang were generally monophic and they often accompanied themselves with an instrument like a lyre or even a drum. 4. What are modes? Describe at least one type of mode. Modes were used before the modern day scales. One Kind of mode is Ionian. 5. What is polyphonic music? How does it differ from monophonic music?Polyphonic Music uses two or more independent melodies. It differs from monophic music because monophic music was dominated in early middle ages. Critical Thinking Questions 1. Why did early humans develop music? What are some of the ways that they were thought to create music?Early Humans developed music because they wanted to express themselves. One way they were thought to create music was by listening to natural sounds and repeating them. 2. Why is the study of prehistoric and ancient music important? What can we learn from it?The study of prehistoric/ancient music is important because you can see how music  started and how it advanced. We can learn how they lived back then from it. 3. What roles did music play in the life of prehistoric and ancient people? Are the roles similar to or different from the roles that it plays today?Are the roles similar to or different from the roles that it plays today? The role music played was entertainment and Religious support. The roles are similar today its just more diverse. Discussion Questions Please post questions and answers on the UNIT THREE discussion boards. Unless otherwise instructed, you should submit at least one full paragraph for each question. Each discussion assignment is worth 5 points.

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Societal Boundaries in Kate Chopins The Story of an Hour...

Societal Boundaries in Kate Chopins The Story of an Hour and Desirees Baby As humans, we live our life within the boundaries of our belief systems and moral guidelines we were raised with. Kate Chopin’s â€Å"The Story of an Hour† and â€Å"Desiree’s Baby† tells the story of two women who live according to those societal boundaries. American author Kate Chopin (1850–1904) wrote about a hundred short stories and two novels in the 1890s. Most of her fiction is set in Louisiana and most of her best-known work focuses on the lives of sensitive, intelligent women. After her fathers death, Kates family included her widowed mother, her widowed grandmother and her widowed great-grandmother.†¦show more content†¦Themes as self-reliant women as protagonists, post Civil War racism, male/female relationships and what would eventually become known as male chauvinism are common. These were difficult times for many women because of the domination of men over them. A woman was expected to act and behave in ways tha t were submissive to men in every aspect of their life. Indeed, a woman’s life revolved around her husband and his needs and desires. Women had very little say in their own ambitions or desires. Behaving in non-conventional ways would mean being shunned from society. However, one woman’s world revolves around and for her husband while another dreams of a life free of marital boundaries. Nevertheless, Kate Chopin uses two types of irony in â€Å"The Story of an Hour† to reflect her views. Situational irony refers to the opposite of what is supposed to happen, and dramatic irony occurs when the reader knows something that the rest of the characters in the story do not know. The irony in this short story makes the reader understand that the unexpected happens in life. The first irony detected is in the way that Louise reacts to the news of the death of her husband, Brently Mallard. â€Å"She did not hear the story as many women have heard the same, with a paralyzed inability to accept its significance†. Instead, she acceptsShow MoreRelatedAn Analysis Of Kate Chopin s Chopin 1690 Words   |  7 PagesKate Chopin was a famous American author of many short stories and novels. Chopin is now considered to have been a predecessor of the feminist movement and a leader of the feminist authors of the late 19th and early 20th centuries. Kate Chopin lived a rather traditional life as a housewife until her husband’s untimely death, which significantly changed the course of her life. Chopin s career as a writer actually began when she started facing financial struggles due to the death of her husband. Chopin’s