The term brain plasticity, also called neuroplasticity, stands for the ability of our nervous system to change itself both functionally and structurally. This happens naturally over time, as well as in response to injury.
In a literal sense, plasticity is the ability of a physical object to be manipulated physically. So putting that in the context of your brain means that your nervous system has the ability to respond to internal and external stimuli by reorganizing its structure, connections, and functions.
Plasticity is an important part of the neural development of your brain and the proper functioning of your nervous system. It also responds to a changing environment, aging and possible diseases. It’s there to help neurons take on new properties, but also to make sure you always have enough neural connections.
Our brains are “plastic” structures. Several scientific studies have shown this. We also know that brain plasticity occurs in multiple nervous systems. Plasticity is located in your nervous tissue, neurons, glial cells and synapses, among others.
How do neural networks work?
Brain plasticity usually arises in response to physiological needs, changes in neural activity, or damage to nerve tissue.
Plasticity plays a role in the formation of your neural networks as you grow up, learn new motor skills, or other things you will use for the rest of your life. Plasticity also plays a role in many biological processes, such as:
- cell migration
- changes in neuronal excitability
- creating new connections
- changing existing connections
Structural and functional brain plasticity
The plasticity and efficiency of transfer between neurons depends on adaptive changes of presynaptic, extracellular or postsynaptic molecules. This means that plasticity can occur without changing certain things , such as:
- the number of
- the placement
- the layout
- the total area of the synapses
- the density
Clear examples of this kind of plasticity are early long-term potentiation and changes in electrical properties of geometric changes in dendrites.
On the other hand, we see structural or architectural plasticity. These are changes in circuit connectivity that involve the formation, elimination, or expansion of synapses, such as late long-term potentiation.
Hebbian and homeostatic plasticity
The plasticity of transmission efficiency and structural plasticity can also be classified as Hebbian and homeostatic brain plasticity, respectively.
In Hebbian plasticity, there is a change in the strength of a synapse. This can mean either an increase or a decrease, and it can happen seconds or minutes after a stimulus.
Early long-term potentiation is typical of Hebbian plasticity. It starts when a stimulus activates the corresponding pre- and postsynaptic impulses, which will increase synaptic efficiency. That stimulus will also help to increase potentiation. In other words, the Hebbian plasticity creates a cycle of positive feedback.
Homeostatic processes, on the other hand, are much slower. They can last for hours or days. They can also change the density of the ion channels, the release of a neurotransmitter or the sensitivity of a postsynaptic receptor.
Unlike Hebbian plasticity, homeostatic plasticity creates a cycle of negative feedback. The homeostatic species decreases connectivity in response to a high degree of neural activity. Connectivity picks up again once that activity has declined.
Hebbian and homeostatic: two different roles
It is argued that Hebbian and homeostatic plasticity have different roles when it comes to neural network functions. Hebbian plasticity plays a role in:
- the changes that take place in our lives
- our ability to store memories
- the durability of memory
Homeostatic plasticity affects the self-organization of your neural network. This is to keep the network stable. This kind of plasticity also makes use of synaptic and extra-synaptic mechanisms, such as:
- the regulation of neuronal excitability
- synapse formation
- synaptic force stabilization
- dendritic branch
You can see plasticity happening as a nervous system develops. It’s an important property that allows your brain to modify its own structure and functions in response to changes in neural activity. It helps you to learn new skills and helps learning in general. It is also important for the development of your memory.
Finally, it is a process that allows your brain to remain flexible. Being flexible means you can adapt better to your environment, which also means you are able to survive.