How does pruning work with motor skills

Synaptic pruning retains enough unused synapses to allow the brain to evolve, adapt and to switch or develop functions as the need arises Shaffer, Synaptic pruning makes it clear that brain development is dependent on all forms of mental stimulation from the outside world. In the introduction to this article, the point is made about the isolation of the brain, except through the sensory nervous system.

Early experiences in visual, aural and tactile stimulation allow for the preservation of more synapses, which in turn improves brain function and allows a greater degree of plasticity.

This highlights the need for play and parental bonding, and communication and mental stimulation during these early years. Music, particularly classical music, is rapidly becoming recognised as a vital stimulant for early brain development. Making the most of the sensory nervous system in babies promotes synaptogenesis.

This and the plasticity of the brain make the recovery from brain injury quicker and easier in children than in adults. The cerebellum gradually learns its functions of balance and equilibrium, smoothing muscle activity, synergy co-ordination of eye and hand movement , and muscle tone regulation. These activities, essential as they are for locomotion, rely heavily on sensory feedback from the semi-circular canals vestibular sensations , and from muscles and joints proprioception sensations , to the cerebellum.

Balance is a major achievement of the cerebellum as the infant attains the unaided erect posture necessary for bipedal locomotion.

Identification by parents and health care professionals at what point these skills are demonstrated for the first time by the child keeps a check on cerebellar development.

A brain growth spurt occurs over the first two years of life. At birth the brain is about 25 per cent of adult weight, but is 75 per cent of adult weight by two years of age. During the first year of life the brain gains 1.

This growth increase is due to replication of glial cells, especially astrocytes, and developments in myelination and synaptogenesis including synaptic pruning , especially of the cortex Shaffer, Lateralisation, the processing of assigning functions to either of the cerebral hemispheres, is well under way by birth and continues into childhood Table 2.

As these mature, both the vocabulary and the use of language increases, but this does depend on sensory input that is, the vocabulary and language use to which the child is exposed Table 3.

Infancy is often defined as the period from birth to the development of a language. A wide range of genetic and chromosomal disorders can result in varying degrees of mental retardation, or even arrest of further mental development, especially rare gene defects on the X chromosome. Disorders including autism Aylott, , Rett syndrome, attention-deficit hyperactive disorder, and Tourette syndrome are now widely believed to have a genetic basis Folstein et al, ; Blows, ch 5.

Genetic screening and counselling of affected families by health care professionals will become increasingly more important as genes are discovered and genetic testing is made more available. Management of familial genetic disorders requires sensitivity on behalf of the health care professional in understanding the dilemmas facing the family. This applies particularly when families must answer questions about whether or not to have children.

In order to facilitate the choices open to the family, knowledge of the science of genetics is as important to the nurse or counsellor as an understanding of the management options. This period is critical for the moulding of the brain, and education is the key factor in this process. This is achieved by further myelination, strengthening synapses and by utilising plasticity. Education plays a vital role in the process of moulding the brain, as those synaptic pathways that are used regularly will be reinforced, and this forms the basis of learning.

Rehearsing knowledge such as learning spelling creates synaptic connections that will last as long-term memories for life. Synaptic pruning ensures that established connections become efficient, without the clutter of unwanted synapses.

These are the best years for learning; for example, music skills are best learnt up to the age of nine years. Music training in pre- and junior school children is the best way to develop the type of neural connections needed for abstract reasoning, science and mathematics later in life Anon, A lack of education during these years results in deficits in learning that are likely to be a problem for life.

For this reason, children in hospital for long periods should be provided with teaching in the wards. Changing schools can also be disruptive to learning, especially if this happens regularly - children of travelling parents, for example.

A long period of stability at the same school is desirable for the best brain development. Other factors affecting learning, such as persistent bullying at school or an unhappy home life, will take a toll on both the brain and intellectual development. Fine-tuning of motor skills continues throughout childhood, with the development of motor skills programmes rather like computer programs , which are stored as long-term memory in the motor association cortex.

These programmes allow skills such as riding a bicycle to become second nature. Developing motor programmes involves repetitive practice of the motor skill, with feedback on performance, and usually forms part of the education curriculum at school, for example, hand-writing, gymnastics, football or learning musical instruments.

Child abuse, be it physical or psychological, has very severe implications on brain development. Detrimental changes in the pattern of synaptogenesis and plasticity occur as a result of the stress from abuse, and these changes have life-long consequences. Toxic stress weakens the architecture of the developing brain, which can lead to lifelong problems in learning, behavior, and physical and mental health.

Experiencing stress is an important part of healthy development. Activation of the stress response produces a wide range of physiological reactions that prepare the body to deal with threat. However, when these responses remain activated at high levels for significant periods of time, without supportive relationships to help calm them, toxic stress results.

This can impair the development of neural connections, especially in the areas of the brain dedicated to higher-order skills.

All of these numbers are estimates, calculated in a variety of different ways, but we are making this change in our materials after a careful review of additional data that were called to our attention.

The Center is deeply committed to a rigorous process of continuous refinement of what we know and an ongoing pledge to update that knowledge as additional data become available. The Brain Architecture Game was designed to help explain the science of early brain development—what promotes it, what derails it, and what the consequences are for society. View Related Key Concepts. Briefs : 8 Things to Remember about Child Development.

In particular the scientists identify a protein called PlexA1, a major receptor molecule that attracts semaphorins. Semaphorins prevent axons from forming in inappropriate regions of the nervous system. In the case of mice -- which spend most of their time on four paws - signaling between a semaphore protein called Sema6 and PlexA1 activates in young mice.

This eliminates critical synaptic links between nerve cells to stop the formation of sophisticated CS neural connections and fine motor skills. Inhibition of PlexA1 signaling during childhood might be a way to restore these skills. Key collaborators on the study includes John H. After learning the PlexA1 protein eliminates sophisticated motor neuron connections in maturing mice, the researchers bred mice that don't express the gene regulating it gene designation PlexA1.

As PlexA1 mutant mice mature into adulthood, they lack the elimination of CS synaptic and motor neuron connections. In feeding tests involving both short narrow strands of pasta and food pellets, mutant PlexA1 mice were significantly more skilled and faster than normal mice at grabbing and eating food. When researchers tested mutant PlexA1 mice in skilled walking tests conducted on balance grid , mutant mice did not perform significantly better than normal wild-type mice, according to the authors.

To understand differences in PlexA1 levels in mice and humans, study authors compared genetic and molecular regulation of CS neural connections in the mouse and human motor cortex of the brain. This region controls voluntary movements and other critical tasks. Human tests of the motor cortex were performed with donated human brain tissue. The scientists determined differing PlexA1 expression is caused by what are called cis-regulatory elements.

These are regions of non-coding DNA that help regulate nearby genes.