Neuroplasticity, I can say, is one of the arousing curiosity branches of neuroscience, as plasticity refers to a substance that can reorganize its shape; the brain can also reorganize itself by forming new neural connections [1].
The present writing summarizes information concerning the mechanisms that neuroplasticity uses, the effects of the reorganization in the brain, and modifications in the brain related to age and gender.
Neuroplasticity has forms like adaptive and maladaptiveplasticity [2]. Four mechanisms of neuroplasticity areinterrelated with each other to perform modifications in the brain [3].
Synaptic plasticity is the mechanism that reforms synaptic strength using two important processes. They are called (LTP) long-term potentiation and (LTD)long-term depression [4].Long-term potentiation has a pivotal role in learning things and memorising; this role of LTP comes from increasing the number of receptor density and neurotransmitter release at the active synapses, at the same time enhancing synaptic strength.The frequent practice of a skill consolidates these strengthenedconnections [5]. For example, learning a new language, practising a skill, going to a gym, doing yoga, and many habits are good examples of an adaptive form of plasticity as they are emerging as our hobbies as a result of strengthened synapticconnections [6].
LTD is a process that refines synaptic networks. Its beneficialside occurs when the brain prunes unnecessary synapses to refine motor skills and optimize information processing [8].However, an extensive LTD in hippocampal (a brain region vital for memory and spatial navigation) circuits can cause neurodegenerative diseases, including Alzheimer’s disease [7].
Structural plasticity is the condition where the brain canchange its shape physically. Synaptogenesis, formation of dendrites and axonal sprouting take place in this neuroplasticity mechanism. Synaptogenesis, dendritic remodelling, and synaptic pruning can lead to adaptive outcomes when learning new things. On the other hand, the usage of drugs such as cocaine and other addictive behavioursleads to abnormal dendritic growth and synaptic pruning.[8].
Neurogenesis is the formation of new neurons. This activity predominantly takes place in the hippocampus; it is related to activities in our Daily life, such as learning new skills, emotional regulation, and cognitive abilities that help greatly form new neurons, in contrast, chronic stress and elevated cortisol levels have negative effects on neurogenesis, which can cause depression and anxiety [9].
Functional reorganization, as the term explains itself, it is the mechanism of the brain that compensates for neural damage by finding and giving tasks to the underutilized or alternative regions of the brain [10]. For instance, let’s say a person experienced an accident that caused a stroke to his brain, and this left the motor cortex unable to accomplish motor functions. At this stage, the contralateral (right) cortex takes a partial responsibility for the damaged cortex. At the same time, the damaged cortex starts to recover itself
Mechanisms discussed above have been examined in isolation; however, current studies have shown that they show a great interdependence on each other [6].
Adaptive and maladaptive plasticity.
Whether changes that emerge in the brain have positive or negative consequences depends on the nature of the stimulus, genetic predispositions, and environmental conditions [8].Plasticity that leads to recovery from illnesses or enhanced skills has a positive effect on our body and is called adaptive plasticity. It is the ability of the brain that maintains cognitivefunctions, facilitating recovery from neurological disorders,and compensating for age-related changes. Negative effects of plasticity emerge when the brain reorganizes itself in harmful ways due to stress, injury, and extensive usage of drugs. At theend, these modifications, which are called maladaptive plasticity, lead to addiction, cognitive decline, neurological disorders, and chronic stress.
Neuroplasticity is not static throughout the lifespan [3]. Age, gender, hormonal fluctuations, genetic changes, and environmental conditions have an impact on neuroplasticity.
The activities we do in the early development and during childhood are important because at these ages, neuroplasticity occurs rapidly, which enables learning and adaptation to any condition. On one hand, positive activities such as taking care, spending enough time, and social interactivity can increasedendritic growth and healthy circuit formation, while adverse childhood experiences can lead to traumas, chronic stress, and disorders of the brain [3]. Continuously learning and challenging the brain builds a ‘cognitive reserve’, which confers resilience against certain neurological diseases.Psychosocial factors are also important for good neuroplasticity. Social activities and stress management skills can also contribute to enhancing neuroplasticity [8].
The brain is not just an organism; it is the place where the mind lives. Studying neuroplasticity and its fundamental mechanisms allows us to understand behaviours, disorders, and cognitive processes [8].
References
https://doi.org/10.1016/j.conb.2011.01.006
