Wednesday, September 23, 2009

American Crew Product Toronto

DELETE traumatic memories


A new element is adds to the understanding of phenomena related to memory. And 'know that traumatic experiences leave their mark, often permanent, due to the great excitement caused by the event. I do not have the fond memories intrusiveness el'ossessività characterizing those related to emotionally stressful situations. ipermemoria The el'ipervigilanza constitute a distinctive the personality of traumatized individuals, so that painful memories can wake to a minimum signal associated with the trauma, or recur spontaneously, recurrent forms, such as flashbacks or nightmares, waking during sleep. A deficit in extinction of unpleasant memories is particularly important about the fear and limits the effects of the treatments for anxiety disorders. The extinction of fear involves the inhibitory influences of the prefrontal cortex on the amygdala (limbic system structure that is the sentinel of the emotions, able to respond prior to the neocortex, and eventually, to make a sort of "emotional attachment"). Onto the structure of the amygdala has focused the attention of a study group led by Nadine Gogolla, a researcher at the Department of Molecular and Cellular Biology, Harvard University, identified a process that contributes to the permanence of fearful memories. Preliminary results of the study, conducted on mice, were published in the journal Science, with a focus Pizzorusso edited by Thomas, a researcher at the Institute of Neurosciences of the CNR of Pisa. Fear can be induced experimentally in laboratory animals. The anxiety that is learned by associating a neutral stimulus that produces a feeling harmless (conditioned stimulus, for example, the sound of a bell or a white cage) with a reinforcement negative (unconditioned stimulus, such as a brief and mild electric shock to which the animal can not escape in any way), is called "conditioned fear". The opposite process, the extinction of fear, is a technique that is based on the decrease in fear responses when you break the association between the conditioned stimulus and the unconditional, repeatedly presenting the conditioned stimulus without making it follow from the shock. And 'now commonly accepted that extinction represents new learning rather than eradicate the existing memory. In contrast, the original memory may return spontaneously, or may be resumed, if the stimulus is condiziononato presented in a different context than that of the extinction protocol was effettuato.Le animal studies have clearly shown that the effectiveness of learning related to the process of extinction depends on the age. In young memories of fearful events can be deleted permanently, while in adults the fear conditioning induces the formation of memories resistant to treatment with extinction. These observations suggested the hypothesis that memories of fearful emotions are actively protected adults. The research group has shown that protection is conferred by the chondroitin sulfate proteoglycans (CSPGs) present in the perineuronal network (a highly structured extracellular matrix around the inhibitory neurons), which constitutes the backbone of the amygdala. The experiments were conducted in mice during the postnatal period (16 days and 23 days after birth) and adult mice of three months. The organization of CSPGs into perineuronal network coincides with the crucial period that marks the transition to the stage of development (age youth to adulthood, around the third week of life) in which the memory of fear becomes persistent. If the extracellular matrix is \u200b\u200bremoved in the amygdala of adult mice using a specific enzyme, is facilitated extinction of conditioned fear responses, indicating a network that mediates the formation of perineuronal intact memories committed to eradicate resistant to fear. Nadine Gogolla also noted that the chemical degradation of the matrix works to erase unpleasant memories only if it is made before the fear conditioning and does not act on those already existing. This indicates the possibility that the presence of the protective net modifies the process by which painful memories are stored in the brain. It 's a small step forward in our knowledge of the neurobiology of fear, and may lead to the development of drugs needed to prevent, if not cure anxiety disorders, the most vulnerable. MICELI Rosalba

TAKEN FROM
WWW.LASTAMPA.IT

0 comments:

Post a Comment