What Is Neuroplasticity?

Neuroplasticity explains the relative repair of certain brain areas when an injury occurs, among other aspects related to basic cognitive processes.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 16 March, 2021

Neuroplasticity, or neuronal plasticity, are terms that refer to the ability of the human nervous system to modify itself and form nerve connections in response to new information, sensory stimulation, development, dysfunction, and damage. This capacity means that the brain changes throughout its life in response to the environment.

A brain weighing 1,400 grams (three pounds) has about 100 billion neurons, with thousands of synapses sending information to all the body’s organs and limbs. It’s a system that has always been considered to be rather rigid in its structure, but neural plasticity is starting to challenge this idea.

Thus, neuroplasticity is associated with the learning and development that takes place during childhood, but its definition encompasses much more and is applicable to several areas of great interest. If you’d like to know everything about this incredible phenomenon, keep reading.

About neurons

Before entering fully into the subject that concerns us today, it’s important to lay certain foundations and principles surrounding the human nervous system. And what better way to do it than by defining its basic cellular structure, the neuron, and its particular form of communication?

A neuron is defined as the representative cell in the functionality and physiology of the nervous system, as indicated by the Ambientech portal. Its function is to transmit electrical impulses (through a process called the synapse) from the information center to the organ, tissue, or effector cell.

The parts of the neuron

We can distinguish four functional parts in a neuron. These are the following:

• Nucleus: Located in the cell body, delimited by the cytoplasm and highly visible. Here we find the neuron’s genetic information, and so it acts as a storage center for instructions for protein synthesis and its metabolic processes.
• Perikaryon: This refers to the cell cytoplasm, that is, the environment where the organelles lie. One of the most notable organelles in terms of density are ribosomes, responsible for synthesizing proteins. The perikaryon and the nucleus constitute the soma or neuronal body.
• Dendrites: These are the branches of the cytoplasm of the cell body. Their function is to receive electrical impulses from other neuronal bodies and increase the effective surface of the neuron without compromising its total volume.
• Axon: This is the “cable” that protrudes from the soma and which transmits the electrical impulse from the neuronal body to the effector cell. As it’s surrounded by an insulating layer (the myelin sheath), it allows electrical information to travel up to 120 meters (400 feet) per second. A single axon can measure up to a meter (three feet)

With this little introduction, you’ll now have an idea regarding the shape and function of a neuron. These cell bodies communicate with each other through electrical and chemical synapses, transmitting information through hyperpolarizations and cellular depolarizations based on the entry and exit of ions through membrane channels.

The brain of an adult human being contains about 100 billion neurons. Conceiving life without this cell type is impossible.

What is neuroplasticity?

We now go back to the definition of neuroplasticity we mentioned earlier, in this case by the Neuron portal (Cognitive Academy): it’s the ability of the brain to reorganize its neural connectivity patterns, readjusting its functionality over time, based on external and internal changes.

It’s a quality that occurs throughout the life of the individual and, furthermore, is seen in normal aging patterns. This complex term can be summed up in a number of key concepts. Among all the possible ones, we find the following:

1. It’s assumed that certain neuronal groups can respond to supply the nerve deficiencies corresponding to an injury.
2. The ability of a neuron to assume the role of another one that is injured.
3. There’s the possibility of neuronal reorganization and the growth of new synapses from one or more damaged neurons.
4. There’s an adaptive capacity to minimize the effects of brain injuries through the modification of its own structural and functional organization.

As you can see, we’re dealing with mainly pathological terminology. From a medical point of view, the greatest point of interest in neuronal plasticity is that neurons can adapt to compensate for the effects of damage or weakness in the brain. Even so, it should be noted that this capacity is limited.

This “functional recovery” of neurons allows us, to a certain extent, to alleviate the effects of diseases such as multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, dyslexia, attention deficit disorder (ADD), and other psychological irregularities, such and as indicated by the Cognifit portal.

Processes involved

Although it may seem a bit complex, it’s actually very beneficial to explore the neurobiochemical and neurogenomic processes involved in neuroplasticity. Specialized studies help us to explain it to you in the simplest way possible.

1. Genetics and protein expression

There are some immediate gene products that directly regulate neuroplasticity. For example, the FOX, Homer1a, and NACC-1 genes. The FOXP2 gene is expressed in motor circuits related to speech and language, influencing the thalamus, cerebellum, and basal ganglia, among other structures.

Mutations in this particular gene are associated with learning and speaking difficulties. Furthermore, in its normal expression, it’s involved in the production of coordinated orofacial movement sequences.

2. Neurobiochemical processes

This section is based on intrinsic excitability and synaptic plasticity, which promote neuronal plasticity in terms of potentiation and inhibition in the long term. We’ll briefly tell you what this terminological conglomerate consists of.

When human beings are faced with a new learning or experience process, the brain establishes a series of neural connections, called synapses (of an electrical nature). These connections can be regenerated throughout the life of the individual, and, the more an experience is repeated, the more strengthened the synapse will be.

On these bases rests the phenomenon of synaptic plasticity, as the more we learn about something, the easier it is for us to approach it again. When communication between the neurons involved is strengthened, the cognitive process occurs more quickly. Isn’t that incredible?

3. Neurogenesis

Neurogenesis can be defined as the formation of new neurons during fetal development (embryogenesis). For a long time, it was believed that neurogenesis in adults was a biological impossibility as the formed neurons don’t divide and survive until the end of our lives.

Even so, postnatal neurogenesis has recently been demonstrated in certain areas of the body. This could be very important for the development and refinement of memory and learning processes, although we still have a lot to discover as a society in relation to this issue.

Neurogenesis is important for the maintenance of brain homeostasis and for the plasticity and preservation of cognitive function.

4. Compensatory functional plasticity

When a brain injury occurs or neurons in a specific area are weakened by aging itself, there’s a reorganization of the functions lost at a neuronal level. This is achieved through a series of regeneration, collateralization, and rearrangement factors of the lost function in areas surrounding the affected area.

For example, it has been observed that the brain reaches a maximization of functionality by activating other nerve pathways when the traditional ones fail, either due to injuries or due to the passage of time. It certainly isn’t a miraculous mechanism, but understanding it in its entirety is essential in order to unlock the secrets of the human mind.

5. Extraneuronal plasticity

We don’t want to immerse ourselves in overly complex terminology, but it’s enough for us to know that not all neuroplasticity processes are determined by neurons. For example, integrins and glycans (extracellular compounds) have been shown to be essential in synaptic plasticity, development, and nerve regeneration.

Advantages of neuroplasticity

Sources already cited explore the advantages of neuroplasticity in our life in the short and long term. Among them, we find the following:

1. It allows us to acquire new capacities, human development, learning, and a considerable improvement in cognitive abilities over time.
2. It improves the functional capacity of the brain, helps to alleviate certain pathological processes, promotes the recovery of sensory losses, and improves motor control and memory skills.
3. Last but not least, this mechanism is essential for the recovery of functionality after brain injury.

Neuroplasticity is key to processes such as adaptability to change, organization, and memory. Portals such as the Association for Progress and Management (APD) argue that this is essential for development in companies and practical areas, as it improves communication skills and personnel selection, among other things.

Brain training based on neuroplasticity is associated with greater efficiency in environments characterized by pressure, stress, and great responsibility. While we shouldn’t see these mechanisms as the answer to every challenge or problem, understanding the adaptability of the brain is essential to maximizing our abilities.

Furthermore, neuropsychological rehabilitation takes advantage of this regenerative capacity to generate new synapses in patients with brain damage, although there’s no clear consensus on how far this mechanism goes. Age, genetic factors, the severity of the pathology, and other factors condition the recovery process beyond plasticity.

Summary

While neuroplasticity is a fascinating and proven phenomenon, you have to be careful. Not all physiological processes can be included in the umbrella of neuronal regeneration since, without going any further, neurogenesis in adults was unknown until a few years ago. There’s still a long way to go and much to discover.

Synaptic plasticity, neuronal role change, and neurogenesis are essential processes to understand the evolution and development of patients with certain psychological pathologies.

As much as the boundaries are still being debated, it’s clear that these underlying mechanisms are essential to understanding the human psyche and its illnesses in equal measure.