Science: Sculpting Memory? The hippocampus is a "general" who commands hundreds of thousands of nerve cells.

Recently, scientists at the Weizmann Institute have successfully recorded these rapid bursts of nerve activity in the human brainThey affectionately call it the "seahorse" (also quite vivid, like the sound of a concert or a grand prix audience) and prove that they are the basis for carving new memories and subsequent memoriesThe study was published in ScienceDOI:10.1126/science.aax1030a dazzling fireworks show" in terms of its intensity and timing, the ripples were simply amazingIt is an carefully planned burst of simultaneous activation by about 15% of the hippocampus neurons -- all of which discharge at the same time in about a tenth of a secondIt's like a well-arranged fireworks display for nerve cellsProfessor Rafi Malach of the Department of Neurobiology at the Weizmann Institute saidresearchers have found for the first time that this discharge occurs in the rodent's sleep and rest mental state and plays an important role in the rodent's spatial navigation memoryUntil recent years, researchers have found in the hippocampus of primates that this simultaneous electrical activity in large groups of neurons can occur in a sober stateBut so far, scientists still know nothing about the role of this hippocampus in human cognitive and psychological activitiespractice real knowledge and great dedicationusing MRI to monitor electrodes (yellow dots) implanted in the hippocampus of epilepsy Patients Source: Weizmann Institute of ScienceAlthough humans are free to communicate what they think, most methods do not provide scientists with a detailed view of what is happening at the same time in the brainSo Yitzhak Norman, a doctoral student at Malachi Labs, led the current study with a team of researchers from the Feinstein Institute of Medicine, Professor Ashesh MehtaIn this clinical procedure, the doctor will insert electrodes into multiple brain regions of patients with refractory epilepsy, locate the epilepsy lesions and surgically remove the lesions These patients volunteered to participate in memory tests while waiting in the hospital during seizures During the experiment, the researchers showed patients colorful, visually detailed images, either by celebrities such as Barack Obama and Uma Thurman, or by famous monuments such as the Statue of Liberty and the Leaning Tower of Pisa Patients are required to remember these images in as much detail as possible After viewing the pictures, they were followed by a brief distraction, after which the patient was asked to blindfold and freely recall the images and describe them in detail Throughout the experiment, patients' conversations were recorded, along with their corresponding brain activity, and were shown by electrodes implanted into the hippocampus and other areas of the cerebral cortex linked brain activity to the patient's oral narrative, some surprising observations can be found First, the study found that "seahorse" outbreaks played a crucial role in free recall: a significant increase in the rate of ripples they recalled a second or two before patients recalled and began to describe a new picture Importantly, the hippocampus re-expresses the content of the picture: the image that causes more ripples during the viewing phase, and the subsequent recollections, as well as more ripples general hippocampus the image depicts the patient's intracranial electrode performance (red circle), which measures changes in the cortex electric field while viewing the image and then freely recalls the same image later Photo: Yitzhak Norman Because brain activity is recorded in both the hippocampus and the cerebral cortex, researchers were able to prove that the ripples are synchronized with the activation of the cerebral cortex, especially in the visual center of the brain, where detailed visual information may be stored In addition, the original advanced visual center is thought to be specifically designed to represent a specific visual category - for example, a face is represented in one cortex area and a monument is represented in another So when a patient recalls a face (like Obama), or a monument (such as the Eiffel Tower), the activity of the cerebral cortex is selectively enhanced in the corresponding visual center Norman explains: "In the process of free recall, many of the centres' coordinated activities were revealed, with the hippocampus acting as a conductor refreshes our perceptions these findings greatly expand our understanding of the hippocampus The study emphasizes the importance of synchronized neuronal group activity It should be remembered that the hippocampus outbreak involves the simultaneous activation of hundreds of thousands of nerve cells Malach concluded: "This is a major step forward in our understanding of the neuronal mechanisms behind human memory Sculpting memories, their storage and recall naturally dependon on a complex series of processes However, this 'neuronal drama' of synchronous hippocampus esmory clearly indicates their central role in memory formation and recall "
References: sialys ar gysenome to human free recall sihippocampal sharp-waves linkedto visual episodic re ripple in humans