Neurodegeneration refers to the progressive decline and eventual death (i.e. degeneration) of a group of brain cells termed ‘neurons’.
Neurons are a key cell type in the human nervous system, making up both the central nervous system (CNS) (the brain and spinal cord) and the peripheral nervous system (PNS). They communicate with each other using electrical impulses, sending signals to produce a response to particular stimuli.
There are a number of different types of neuron; sensory neurons which are responsible for detecting stimuli and sending impulses to the CNS, motor neurons which transmit impulses from the CNS to effectors such as muscles and interneurons which relay information between the other two.
Task 1: Visit the following pages and learn more about the basics of the human nervous system
Neurons cannot typically repair or replace themselves and therefore damage or death of these cells is catastrophic. The inability to correctly respond to stimuli leads to problems with mental function and/or movement.
The brain is a complex structure, comprised of the forebrain, the midbrain, and the hindbrain. Each of these areas is divided into many other specialised regions, each having dedicated function(s). If damage occurs/neurons die in any of these areas, this can lead to one of the many types of neurodegenerative disease.
For example, damage to the basal ganglia (an area usually involved in both cognition and voluntary movement) can lead to Parkinson’s disease. This will be discussed in more detail in activity 4.
Task 2: Visit the following page and learn more about the main brain regions and their functions. Can you think of what diseases may be caused by damage to any of them?
As you have seen already, there are many different neurodegenerative diseases which are a result of damage to different regions of the brain. However all of these diseases have the common feature of declining or dying neurons.