The term “brain plasticity”, also known as neuroplasticity, is related to the ability of our nervous system to change both functionally and structurally. This happens naturally over time or as a response to injury.
Plasticity is literally the ability of a physical object to be manipulated in a physical way. When you think about it in the context of your brain, it means that your nervous system is able to respond to internal and external stimuli. It does this by reorganizing its structure, connections, and functions.
Plasticity is an essential part of your brain’s neural development and the proper functioning of your nervous system. The brain also responds to your changing environment, aging, and all diseases. Plasticity is said to help neurons adopt new properties. At the same time, it should also ensure that you always have enough neural connections.
Our brain consists of “plastic” structures. Several scientific studies have shown this. We also know that brain plasticity occurs at different organizational levels of the multiple nervous system. Plasticity is found in your nerve tissue, your neurons, your glial cells, your synapses, etc.
How do neural networks work?
Brain plasticity occurs mainly in response to physiological needs, changes in nerve activity, or due to nerve tissue damage.
Plasticity also plays a role in the formation of your neural networks as you grow up, learn new motor skills, or other things that you will use throughout your life. In addition, plasticity also plays a role in many biological processes, such as:
- Cell migration
- Changes in neural excitability
- Establishing new connections
- Change of existing connections
Structural and functional brain plasticity
The plasticity and efficiency of transmission between neurons depends on adaptive changes to presynaptic, extracellular, or postsynaptic molecules. This means that plasticity can occur without changing the number, placement, layout, density, or total area of your synapses.
Long-term enhancement in the early phase and changes in electrical properties due to geometric changes in the dendrites are clear examples of this type of plasticity, as well as changes in the connectivity of circuits that involve the formation, elimination, or expansion of synapses.
Hebbian learning rule and homeostatic brain plasticity
The plasticity of the transfer efficiency and the structural plasticity can also be classified as Hebb’s learning rule or homeostatic brain plasticity.
With Hebb’s plasticity, the strength of a synapse changes. This can mean either an increase or a decrease. Also, this can happen within seconds or minutes of a stimulus.
Long-term reinforcement in the early phase is a typical example of Hebbian plasticity. It begins when a stimulus activates the corresponding pre- and postsynaptic impulses, which increases synaptic efficiency. This boost will also help increase potentiation. In other words, Hebbian plasticity creates a positive feedback loop.
Homeostatic processes, on the other hand, are much slower. They can take hours or days. They can also change the density of ion channels, the release of a neurotransmitter, or the sensitivity of a postsynaptic receptor.
In contrast to Hebb’s plasticity, homeostatic plasticity creates a negative feedback loop. The homeostatic form decreases connectivity in response to high levels of neural activity. As soon as this activity ends, connectivity will be restored.
Hebbian and homeostatic brain plasticity: two different roles
Some researchers have suggested that Hebbian and homeostatic plasticity play different roles in relation to the functions of the neural network. Hebb’s plasticity plays a role in:
- the changes that are taking place in our lives,
- our ability to store memories
- the persistence of memory.
On the other hand, homeostatic plasticity has to do with the self-organization of your neural network. This is done to keep the network stable. This type of plasticity also uses synaptic and extra-synaptic mechanisms, such as these:
- Regulation of neural excitability,
- Formation of synapses,
- Stabilization of synaptic strength,
- dendritic branching.
You can observe plasticity as a nervous system develops. It is a key attribute that allows your brain to change its own structure and function in response to changes in neural activity. It also helps you learn new skills as a basis for learning, memory, or relearning after an injury.
In summary, plasticity allows your brain to remain flexible. Because to be flexible means to adapt better to the environment and thus to be able to survive.