Brain plasticity

• Brain plasticity


  te ability of neural connections to grow and reorganise
• Developmental plasticity


  the ability of neural connections in thebrain to reorganise in response to sensory input from the environment.
• Adaptive plasticity


  the ability of neural connections in the brain to reorganise in response to learning new information or to compensate for lost functions and take advantage of remaining functions.
• Stages of plasticity during infancy

  Proliferation, Migration, Circuit formation, Synaptic pruning, Myelination
• Proliferation


  The growth and division of cells, including neurons, leads to the increase of total cell number.
• Migration


  Newly generated neurons move throughout the brain until reaching their final position; this positioning allows for connections between neurons (neural circuits) to be made.
• Circuit formation


  After migration, neurons are able to form neural circuits whereby neurons send electrochemical messages between each other. These connections can be clusters of neurons, as wells as over larger distances within the brain.
• Synaptic pruning


  When neurons that do not form active neural connections die, increasing the efficiency of the nervous system by allowing the remaining neural connections to strengthen and grow in complexity.
• Myelination


  Myelin starts growing over the axons of the neurons, insulating neural connections and allowing for faster and more efficient nerve impulse travel throughout the brain.
• Brain Plasticity in adolesence

  Circuit formation, Synaptic pruning, and myelination continue to occur during adolescence, contributing to the ability for learning and development to continue. For example, myelination in the prefrontal cortex does not conclude until around 20, so the pre-frontal cortex is not fully developed in adolescence.
• Cerebellum during adolesence


  continues to grow in volume with total volume being reached at approximately twelve years of age in females, and fifteen in males.
• Corpus callosum during adolescence

  thickness increases during adolescence through myelination, and various regions grow at different rates. Research suggests hormonal surges account for these growth patterns.
• Amygdala during adolescence


  The amygdala grows in volume during adolescence. In adults, the prefrontal cortex guides the amygdala, but in adolescence, the prefrontal cortex is not developed yet. This means that the amygdala controls decision-making, leading adolescents to become highly reactive to emotional stimuli, act without thinking, or misinterpret situations.
• Frontal lobes during adolescence


  frontal lobes evaluate emotions and use rational thinking before responding to stimuli. This is not characteristic of teens because this region is not yet mature. it is not fully myelinated; therefore, teens have less white matter in this region compared to adults. This leads to poor decision-making, poor impulse control, planning, and reduced emotional regulation.
• Pre-frontal cortex development during adolescence

  synaptic pruning continues in the prefrontal cortex during adolescence, reducing grey matter and allowing for more complex and efficient connections to be created in the brain. Because synaptic pruning begins at the back of the head, the pre-frontal cortex is the last to be pruned. This makes it easier to understand why teens struggle to assess risks, risky behaviour, emotional regulation, and recognise others' emotions.