What Is Brain Plasticity and Why Is It So Important?
Neuroplasticity, or brain plasticity, is the brain's ability to regulate its connections or make new connections. Without this ability, no brain, not just the human brain, can develop from infancy to adulthood or recover from any brain injury. Unlike a computer, what makes the brain special is; It is the parallel processing of sensory and motor signals. The brain has many neural pathways that can take over the function of another, so minor errors in development or temporary loss of function due to damage can be easily corrected by rerouting signals along a different neural pathway.
However, errors that occur in development -- for example; Like the Zika virus that affects the brain development of the baby in the womb, or damage from head bumps -- it's pretty serious. Still, even in these examples, when the right conditions are created, the brain can overcome the downsides to improve some functions.
Due to brain anatomy, certain parts of the brain are responsible for certain tasks. This is something predetermined by our genes. For example, there is a brain region that allows us to move our right arm. Damage to this part of the brain causes loss of movement in our right arm. But with a different part of the brain, you can process the sensation coming from your arm, you can feel your arm but you cannot move it. This "modular" arrangement; means that a region of the brain unrelated to sensory or motor function cannot take on a new role. In other words, neuroplasticity; is not synonymous with the brain being infinitely soft.
Part of the body's ability to track brain damage; it can be explained by rehabilitating the damaged area of the brain, but much of it is the result of neuroplasticity -- the creation of new neural networks. In a study conducted on Caenorhabditis elegans, a nematode (threadworm) species used as a model organism in research, it was concluded that the loss of sense of touch strengthens the sense of smell1. This suggests that the loss of one sense reshapes another. In humans, it is known that losing the sense of sight at an early age strengthens other senses, especially hearing.
In a developing baby, the key to the development of new connections is environmental enrichment based on sensory (sight, hearing, smell, touch) and motor stimuli. The more sensory and motor stimuli a person receives, the more likely they are to recover from a possible brain injury. For example, some types of sensory stimuli are used to heal paralyzed patients -- for example; such as visual environments, music therapy, and physical movements that provide mental fitness.
The basic structure of the brain is formed by your genes before birth. However, its continued development is largely based on a process called developmental plasticity, where the processes of change of neurons and synaptic connections take place. In an immature brain, the formation or loss of synapses involves the transport of neurons through the reorientation and sprouting of the developing brain or neurons.
In an adult brain, there are very few places where new neurons are created. Exceptions are the dentate return4 of the hippocampus (an area associated with memory and emotions) and the sub-ventricular region 5 of the lateral ventricle, where new neurons are generated and then transported through the bulbus (area responsible for processing the sense of smell). The generation of new neurons in this way is not considered an example of neuroplasticity, but may contribute to recovery from brain injury.
Growing and Pruning
As the brain grows, individual neurons mature by increasing the number of synaptic contacts, first through multiple branches (axons that transmit information from the neuron and dendrites that receive information) and then through specific connections. At birth, each "baby" neuron in the cerebral cortex has about 2500 synapses. By the age of two or three, the number of synapses per neuron increases to about 15,000 in the process of synaptogenesis, a process where a baby explores the environment and learns new abilities. But in adulthood, the number of synapses is halved in a process called synaptic pruning.
Opening New Paths
We maintain our ability to learn new languages, abilities and new activities until old age. This retention capability requires the brain to have a mechanism that can be used to remember, thus storing information over time for future retrieval. This is another example of neuroplasticity, possibly involving structural and biochemical changes at the synapse level. Reinforcing or repetitive activities will eventually cause the adult brain to remember the new activity. Through the same mechanism, the enriched and stimulating environment offered to the damaged brain will eventually lead to recovery. But if the brain is so elastic, why doesn't everyone with a stroke fully recover? The answer to this question also depends on age (younger brains have a better chance of recovery) and the size of the damaged area, and more importantly, the treatments offered during the healing process.
