KIN366/ConceptLibrary/Neuroplasticity

Neuroplasticity

DEFINITION/OVERVIEW

Neuroplasticity is a term of phrase coined from a derivative of the Greek word “plastikos” which means, “to form”. The word signifies the functional and physical vicissitudes that occur in the brain as a result of training and experience (Mundkur, 2005). Lifelong functional changes occur in the brain when we learn, and repeat new patterns of material to enhance experience recognition in the neural pathways throughout the brain.

BIOLOGICAL MECHANISMS OF NEUROPLASTICITY

The development of the brain is sequential in custom and follows a process of neurogenesis succeeded by cell migration and differentiation, followed by axon growth, the formation of synapses, pruning and the the formation of myelin (Kolb & Gibb, 2011). Molecular processes of plasticity are catalyzed by the neurotransmitter glutamate, which recent research discovered to be a dynamic driver to the activation of alpha-amino-3-hydoxy-5methyl-4isoxazole propionate (AMPA) (Mundkur, 2005). The AMPA and NMDA (N Methyl-D-Aspartate) receptors are located on the post-synaptic neuron. As glutamate activates the AMPA receptor there is a subsequent opening of sodium ionic channels that cause local depolarization. This specific polarization is fundamental for the glutamate to bind with the NMDA receptor. It provides calcium an opportunity to permeate through the NMDA receptor, catalyzing a release of trophic factors and activating gene transcription within the nucleus that fosters synaptic connectivity (Mundkur, 2005). Enhanced brain plasticity in the postnatal period is an outcome of the immature NMDA receptor that matures throughout this phase.

EARLY BRAIN GROWTH AND BASIS FOR PLASTICITY

The sequential growth of brain development processes occurs in corresponding stages during the first twelve weeks of pregnancy. In Utero the rapid reproduction of brain cells during neurogenesis manufactures neurons at an alarming rate of between 250 000 to one million every minute (Wesson, 2010). Upon conception every neuron has 7500 connections, which rapidly increase in the post pregnancy phase, during which the formation of synapses and myelin transpire in rapid succession throughout the 1st year and continue late into the 2nd year, finally reaching double the amount of total neuronal connections than that of a fully developed adult brain (Mundkur, 2005). It is of the utmost importance to understand that microbiological process of brain development are only half the equation, and although those processes aid in the regulation of early brain development, it is the experiences that will shape the brains capabilities and insufficiencies (Wesson, 2010).

Experiences can provide revision in the following three means; by influencing gene manifestation, release of neurotrophins, and by impacting the discharge of neurotransmitters that are of vital importance to typical growth and development (Mundkur, 2005). The brain rewires itself in response to the stresses placed on it by the external environments, and it does so with relative ease the earlier in development in which these demands occur. This occurrence is clearly evident in adaptive plasticity, which is one of the four types of plasticity in children, together with impaired, excessive, and plasticity. Adaptive plasticity is the change in neural linkages that foster a skill with repetition, which provide the brain opportunities to adapt and modify based on sensory output (Wesson, 2010). One example of this process is the restructuring of connectivity in the visual cortex as seen in children with amblyopia due to misaligned eyes. An eye patch that covers the opposite eye results in an improvement of vision if done during the first decade of life (Mundkur, 2005). Research, brain mapping, and microscopic investigation of the central nervous system leads to the conclusion that the brain and its development are in no way shape or form static in nature, rather it is a complex system that undergoes dramatic structural and functional changes throughout the course of its lifespan (Mundkur, 2005).

CRITICAL PERIODS OF DEVELOPMENT & PLASTICITY

The critical or sensitive periods are times during maturational phases in which an alteration in the external environment or variation from what is typical will have the largest effect on the transformations of the brain and behaviors (Lillard & Erisir, 2011). The potential for a reduced effect or the potential to have no effect at all greatly increases if the organism was exposed to the same input during a different developmental phase. This is not to say that plasticity cannot occur later in life, rather occurrence tailored synaptic plasticity becomes more restricted and thus more problematic to achieve (Mundkur, 2005). This particular concept is evident in a child’s ability to develop language functions after the whole left hemisphere of their brain was removed, in contrast to that of an adult who undertaking the same procedure would suffer loss of permanent language function (Mundkur, 2005). Evidence through the research and development of brain plasticity illustrate that critical periods of motor development can be of more importance than cognitive development, in regards to plasticity and the development of motor pattern acquisition. Since the brain is not fully developed until the age of twenty (Mundkur, 2005), the ability to achieve higher cognitive advances are attainable, however, since brain plasticity slows dramatically after the first few years of life the ability to develop motor patterns and reflexes dwindle as an organism increases in age. Therefore the importance of motor milestones and critical periods in which gross and fine motor movements are displayed prove vital to practitioners, parents, and educators in their understanding of how to recognize motor deficiencies and their ability to manipulate and enrich the external environment to foster and enhance learning and child development.

PLASTICITY & DEVELOPMENTAL MOTOR MILESTONES

Physical and neurodevelopmental growth advance through sequential stages that allow probable outcomes to be predetermined or predicted by observing and examining a child using a motor milestone framework (Gerber, Wilks, & Erdie-Lalena, 2010). Children typically learn to perform specific tasks at certain ages, so as with any imperative there are always exceptions to the rule, thus the developmental milestones should be exercised as guidelines to understanding the classifications of movement deficiencies that can occur from infancy through to the toddlerhood. There are intrinsic and extrinsic forces calibrating brain plasticity to produce individual distinction between human beings. Intrinsic influences include genetic diversity, temperament, and general being of health and wellness, while the extrinsic influences are predominantly a result of family influence in regards to nurturing approaches, cultural environment, time management and socioeconomic affordance (Gerber et al., 2010). In understanding the deficiencies that can occur movements are broken down into gross and fine motor. Gross motor movements are those that are purposeful and independent in nature and begin as the central nervous system inhibits the primary motor reflexes that were acquired during the gestational period and continue for the first few months (Gerber et al., 2010). Fine motor patterns refer to the purposeful movements made by the extremities that specifically manipulate the environment (Gerber et al., 2010). Motor milestones are uniquely distinct events for a child that are cultivated, and furthermore become most attainable and retainable during critical periods of brain development.

APPLICATIONS OF KNOWLEDGE FOR PRACTITIONERS/ EDUCATORS/ PARENTS

Practitioners, educators, and parents share the ability to influence the external physical environment and fabricate purposeful manipulation of sensory stimuli, in order to create experiences that enhance learning and plasticity in the development of the child. Understanding that practice makes permanent and not necessarily perfect is a sound mantra, in contexts of learning and shaping dendritic density when discussing neuroplasticity. Furthermore, children may present movement or learning deficiencies, however it is of the utmost importance to comprehend that with development and appropriate brain calibration, behaviors and skills can still be learned. Frequently in brain development and hard wiring new experiences failure can often become a prerequisite to learning (Wesson, 2010). The opportunity to stimulate plasticity and wiring of the brain is at its maximum throughout the first 3 years of life (Mundkur, 2005). Consequently critical periods of development and motor milestones become essential in response to detect deficiencies and provide opportunities to cultivate brain plasticity through developmentally appropriate learning cues or tasks. Another approach to enhance sensory and motor functions is to place humans in complex environments where there is an opportunity for individuals to interact with a changing sensory and social environment to engage in far more motor activity than regular (Lillard & Erisir, 2011).

References

Gerber, J. R., Wilks, T., & Erdie-Lalena, C. (2010). Developmental milestones: Motor Development. Pediatrics in Review, 31(7), 267-277. Retrieved from:

           http://pedsinreview.aappublications.org/

Lillard, S. A., & Erisir, A. (2011). Old dogs learning new tricks: Neuroplasticity beyond the juvenile period. Developmental Review 31pg. 207-239

           Retrieved from:http://www.academia.edu/1955440/Old_dogs_learning_new_tricks_Neuroplasticity_before_and_after_critical_periods 

Mundkur, N. (2005). Neuroplasticity in children. Indian Journal of Pediatrics, 72, 855-857. Wesson, K. (2010, August 26). Neuroplasticity. Brain World. Retrieved from February 28, 2013, from: http://brainworldmagazine.com/neuroplasticity/

           Center on the Developing Child at Harvard University, Experiences Build Brain Architecture. [Youtube].  Retrieved from:       
           http://www.youtube.com/watch?v=VNNsN9IJkws