How does our brain manage to store and remember new content over and over again?

I can give a little excursion into neuroanatomy /physiology.

The storage of information takes place in different regions of the brain.

The hippocampus plays a decisive role in this.It is a region in the medial temporal lobe, so more or less central. In addition to the hippocampus, many other brain structures are involved in memory, because there are also different forms of memory. I will briefly explain the forms:

The implicit/procedural/non-declarative memory: Saved movements and sequences without consciously thinking about it like cycling or a pianist playing a song without effort.

The explicit memory: one distinguishes semantic memory (fact knowledge like Paris is the capital of France or 89 fell the wall) and the episodic memory (remember life events e.g. when was my wedding etc).

If one destroys the hippocampi (in each half of the brain there is one), then from the time of destruction the declarative/explicit memory no longer goes.You can’t remember new names, dates, or faces. But you can still learn an instrument, but you would forget that you have learned it.

Then there is the working memory: here information is stored for a short period of time.Sometimes working memory is also referred to as short-term memory. It is independent of the hippocampus. The hippocampus brings the information into the long-term memory of “Encodet”, but long-ago things are stored elsewhere (neocortex).

The hippocampus consists of different cells.Some cells show a so-called long-term potentiation (LTP) with repeated tetan irritation. So such stimuli arrive when you try to learn and save something. The LTP stands for synaptic plasticity. So what Walter Herbert meant here. Potentiation means that the synapses are stimulated as strongly as always, but the stimulus response is stronger. You can observe this stimulus response even after days and weeks. The LTP can also be observed in other brain regions. The LTP is based on properties of the receptors of the synapses. What could also be mentioned in this context is the so-called Papez neuron circle. It consists of several brain regions that are related to each other and also to the hippocampus. A connection of this are the neurons of the corpora mammilaria. These are prone to alcohol. Therefore, these can degenerate in case of severe alcohol abuse and Corsakov syndrome occurs, the patients can no longer orient themselves properly, learn and retrieve things from memory. Other important structures that particularly color the memories emotionally are the amygdala, the hypothalamus and the cingular cortex. They are active at the same time as episodic memory and influence it.

In addition, if we learn something new, it is linked to various other contents in the brain and later it is enough that you only remember part of the link and the rest comes to mind.This is also called consolidation. Thus, a pattern of information is stored e.g. color, pattern, object.

Another addition to the LTP: one can imagine the whole thing in this way, it happens that at the synapse more calcium enters the cell when the stimulus arrives.As a result of signalling processes in the cell, more enzymes for the synthesis and degradation of neurotransmitters, structural proteins and receptor molecules are produced at the post-synaptic membrane (i.e. at the cell to which it is directed). The structure of the membrane changes and as a result its excitability changes.

In addition to the LTP, there is also long-term depression.It is a long-lasting reduction in synapse activity. So it is the opposite. Works slightly differently, but is also important for learning and memory. Mice that were modified to no longer have LTD could no longer orientthemselves in space.

So and now to the Hebb’s learning rules: these 3 rules must be adhered to so that the information can be stored cellularly.1. Co-operative (simultaneous activation of a minimum number of presynaptic fibers is necessary.. the more fibers the stronger the plasticity) 2. Input specificity (only the inputs that are repeatedly irritated, show synaptic plasticity. so show synaptic plasticity. if one prevents memory saturation) 3. Associativity (also flashbulb/flash light if you have a strong irritation and at the same time a low one, both are stored so you can remember exactly what you have just done (not important) as the Twin Towers fell.).

By the way, it has been found that London’s taxi drivers have a magnifying hippocampus.

I hope you can understand it a little bit, it’s not easy and even harder if you don’t know exactly how signal transduction of the cell works and how the brain is built up.

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