How is memory stored and retrieved?

Today, all we know about the brain is a nerve block between the ears. This mass contains knowledge of the world, the history of humanity, all the skills we have learned - from cycling to persuading a lover to give up their love. .Memory makes every human being a unique individual and creates a constant flow for our lives . Understanding about how memories are stored in the brain is a crucial step in the process of discovering people themselves.

The neurons in the brain (Photo: transformedpuppet)

Neuroscientists have made great strides, which are to identify key brain regions and potential molecular mechanisms. However, many important questions remain unanswered and there is a deep gap between molecular-level studies and the activity of the whole brain.

In 1957, HM's patient's announcement of a neuropathic illness gave birth to a new era in memory research. At age 27 HM had surgery to remove large temporal lobes in an effort to treat chronic epilepsy for this patient. The operation was successful but then HM could not remember what happened as well as the people he met. This case demonstrated medial temporal lobes (MTL) which contained seahorse hills that play an essential role in memory formation . HM's case also provides more authentic evidence that memory is not a rigid block. For three consecutive days, they gave HM three 'fool' drawing exercises with three identical themes. As a result, HM's ability to do homework has increased rapidly and markedly after each lesson, although he has no memory of the exercise he did the day before. HM's case has shown how ' remember ' is not the same as remembering 'what'.

From animal experiments and advances in describing the human brain, scientists now have empirical insights into the types of memory that correspond to areas in the brain. However, scientists have not yet filled it

Great Spanish neurosurgeon Santiago Ramón y Cajal (Photo: bio )

The cognitive holes inherently persist for a long time. Although medial temporal lobes have been shown to be essential to the 'narrative memory' - the re-gathering of real events - but there are still unspecified points in this area. How different components interact with each other in coding and memory retrieval is still a mystery. Moreover, the medial temporal lobes are not the final storage of 'narrative memory' . These narrative memories seem to be arranged in the cortex for the purpose of long-term storage, but how this happens and how the memory presented in the cortex is still unclear.

More than a century ago, the great Spanish neurosurgeon, Santiago Ramón y Cajal, argued that memory formation requires a close connection between neurons . At the time, it was believed that neurons were not produced in mature brains, so Ramón y Cajal made a reasonable assumption that changes must occur between existing neurons. Until recently scientists had a few clues to explain how this phenomenon could take place.

However, since the 1970s, research on specific parts of the nervous system has identified ' host ' among the molecules involved in memory formation. In many different organisms, there are many similar molecules involved in both narrative and narrative memory. This is a proof that the molecular mechanisms of memory are conservative on many biological objects. Also from these studies, it is very important that the short form of memory (in minutes) includes chemical changes that work to strengthen the coherence of existing links (synapses) of the neuron, while long memory type (in days and weeks) requires protein synthesis and possibly the creation of new synapses.

Neuron (Photo: turbosquid)

The big challenge now is how to apply these studies to the whole brain. A promising bridge is a process called LTP - a form of synaptic strengthening that has been well studied on rodent's hilly areas. LTP is widely believed to be the physiological basis of memory. It will be a major breakthrough if one can illustrate the conclusion that LTP is really the foundation for in vivo memory formation.

In the meantime questions still appear. Recent studies have found that the neuronal model is recorded when an animal learns a new skill that is repeated when the animal is sleeping. Does this play a role in deepening memories? Other studies show that our memory is not as reliable as we usually imagine. Why is memory not so durable? A hint may come from recent studies that revive the controversial view that memory is vulnerable every time they are recaptured. Finally, in the 1990s people strongly supported the "no new neuron" doctrine . Accordingly, among all positions, hippocampus is the virtual nursery of neurons throughout life. How new cells are born to participate in learning and memory are still unanswered.

Duong Van Cuong