Long-term memory can emerge without obvious involvement of short-term memory.
Memory is divided into different types and subtypes, but most often we hear about short-term and long-term. Short-term memory stores what is happening to us right now or, say, during the day – impressions, conversations, our own thoughts, etc. Part of this is then sent to long-term memory, where it is stored for several days, years, or even the whole life. The transition of information from short-term memory to long-term memory is called memory consolidation; It is believed that sleep plays a large role in consolidation, and that the nerve centers that deal with both types of memory partly coincide and partly do not.
Experiments by employees of the Institute of Neurobiology Max Planck Society in Florida they say that long-term memory can be formed without the participation of short-term memory. Memory and learning are known to depend on the enzyme CaMKII (calcium/calmodulin-dependent protein kinase II), which makes active synapses more stable. An active synapse means that the neurons it connects are working on the same information. If the connection between them remains strong and stable, then the neural circuit they are part of will also remain stable and can continue to work with impulses corresponding to certain pieces of information. In order for interneuron connections and neural chains to strengthen when new important information is obtained, CaMKII is precisely what is needed. It can be inactivated, and then short-term memory will be greatly weakened.
This is exactly what the researchers did with mice. Usually mice do not like bright light and try to be where it is darker. But if you scare them where it is darker, they will remember this and will not go to a dangerous dark place. If they turn off CaMKII, then the dangerous darkness will not be stored in the mouse’s memory, which is what happened in the experiment: an hour after being scared in the dark, mice with turned off CaMKII walked back to where they had recently been scared. But then something strange happened: after a day, a week or a month, the mice suddenly developed a memory of an unpleasant dark place. That is, long-term memory appeared, although short-term memory did not work. The experiments were repeated several times, and in different versions, but the result remained the same. In an article in Nature Neuroscience they conclude that long-term memory can be formed without short-term memory, but what kind of mechanism works there, how information wanders through different neural circuits of different memory departments is still unclear.
We’ve already written about how the relationship between short-term and long-term memory can be quite confusing. In 2017 in Science A study was published that said that both types of memory are formed simultaneously, but long-term memory remains “raw” for a long time, and in order for long-term memory neurons to finally become accustomed to new information, they need to communicate with short-term memory neurons.
Source: www.nkj.ru
