Chapter 5

Neuroplasticity

Neuroplasticity

The ability of the brain to change in response to experience or environmental stimulation.

Neuroplasticity includes:

Developmental plasticity and Adaptive plasticity

Developmental plasticity:

Changes in the brain that occur in response to ageing and maturation.

Adaptive plasticity:

The brain’s ability to restore adequate neural functioning over time after sustaining injury. Can occur throughout the whole lifespan.

• However, it is more efficient in younger people due to the higher levels of developmental plasticity.

Synaptogenesis:

The formation of synapses between neurons as axon terminals and dendrites grow.

Synaptic pruning:

The elimination of underused synapses.

Myelination:

The formation and development of myelin around the axon of a neuron.

Brain trauma

Is damage to the brain that is caused by an external force, e.g. falling and hitting your head or being knocked in the head in a sporting game.

Two key processes of adaptive plasticity include -

Sprouting and Rerouting

Sprouting

Is a neuron’s ability to develop new branches on the dendrites or axons.

Rerouting

Is a neuron’s ability to form a new connection with another undamaged neuron.

Acquired brain injury (ABI) is what?

Refers to all types of brain injury that occur after birth.

There are two types of ABI:

Traumatic and Non-traumatic

Traumatic:

Damage to the brain caused by an external force.

Example - Sports injuries, falls, assaults.

Non-traumatic:

Damage to the brain caused by internal factors.

Non-traumatic - Stroke, aneurysm, tumour, substance abuse, hypoxia (not getting enough oxygen to the brain)

The type of impact on functioning, resulting from an ABI:

Depends on the region of the brain that is impacted by the injury. The impact to functioning can be divided up into three areas; biological, psychological and social.

Type of impact on functioning - Biological:

Changes to the function of organs and neurons.

Type of impact on functioning - Psychological:

Changes to a person’s thoughts, feelings and behaviour

Type of impact on functioning - Social:

Changes to a person’s interpersonal skills and interactions with other people.

Neurological disorders

Diseases characterised by any damage to or malfunctioning of the nervous system.

Some of the most common neurological disorders are:

• Neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease

• Epilepsy

• Multiple sclerosis

• Migraines

Dopamine

A neurotransmitter that is responsible for the coordination of voluntary movement and the experience of pleasure and pain.

Parkinson’s disease (PD)

Is a neurodegenerative disease of characterised by both motor and non-motor symptoms. It involves the progressive loss of neurons in the brain that are responsible for the production of the neurotransmitter called dopamine.

Motor symptoms of Parkinson’s disease include:

Bradykinesia (slowness of movement)

Postural instability

Tremors

Non - Motor symptoms of Parkinson’s disease include:

Pain

Depression

Fatigue

Loss of smell

Stem cell therapy

The use of stem cells to treat or prevent a disease or condition, in this case Parkinson’s disease.

Concussion

A mild traumatic brain injury that temporarily disrupts brain function.

Chronic traumatic encephalopathy (CTE)

Is a progressive and fatal brain disease associated with repeated exposure to mild traumatic brain injuries, such as concussions.

Causes of Chronic traumatic encephalopathy (CTE) include:

• The repeated blows to the head can occur in contact sport, serving in the army or domestic violence.

Or

• These repeated blows trigger an abnormal build up of a protein called tau in the brain which leads to the death of brain cells.

Symptoms of CTE include:

• cognitive impairments including memory loss and difficulties with attention and concentration.

• mood disorders (e.g. depression and anxiety).

• impulsivity.

• executive function impairments such as problems with planning, reasoning, judgement and carrying out tasks.

• aggression.

• dementia.

Post-mortem examination

An assessment of a dead body that occurs to determine the cause of death.

Neurofibrillary tangles

An accumulation of the protein tau that forms insoluble tangles within neurons, which then inhibit the transportation of essential substances and eventually kill the neuron entirely.