What do I remember?
 What are converging neural pathways and their
involvement in light sensitivity?
 What are diverging neural pathways and their
involvement in fine motor control?
 What are reverberating pathways and their function?
 What is the plasticity response and its importance in
the nervous system?
Higher Human Biology
Neurotransmitters mood and behaviour
Part 1
What are we learning today?
Any questions from what you read
 What are endorphins?
 Under what circumstances are endorphins released?
 What is dopamine?
 What is the common term for where dopamine is
produced in the brain, which is also linked to
addiction?
 What is an agonist?
 What is an antagonist?
 What mode of action do some neurotransmitter
inhibitors use?
Endorphins
 Are chemicals that function like neurotransmitters
 Act as natural painkillers by combining with
receptors at synapses and blocking the
transmission of pain signals
 They also reduce anxiety and stress
Action of Endorphins
Ways to Increase Endorphins
 Endorphin production
increases in response
to:
 Physical and emotional
stress
 Severe injury
 prolonged and
continuous exercise
 Certain foods e.g.
chocolate
Other Ways to Increase Endorphin
Production
sunlight
exercise
Listen to
music
laugh
meditation
Effect of Increased levels of Endorphins
 Regulate appetite
 Release sex hormones
Feelings of euphoria
Dopamine
 Dopamine is the neurotransmitter used by the reward
pathway
 Released in pleasure centres of brain found in limbic
system
 It is released on engagement of beneficial behaviours,
e.g. eating when hungry
 It induces the feeling of pleasure and reinforces
particular behaviour in the reward pathway, therefore
linked to addiction
Agonists
 An agonist is a chemical that binds to and
stimulates a specific receptor on the post
synaptic membrane
 They mimic naturally occurring
neurotransmitters
 Trigger a normal cellular response
Antagonists
 An antagonist is a chemical that binds to
specific receptors on the post synaptic
membrane blocking the action of the normal
neurotransmitter
 This reduces or stops normal transmission of
nerve impulses
Inhibitors
 Inhibit the enzymes
which degrade
neurotransmitters e.g.
cholinesterase from
degrading acetylcholine
 Inhibit re-uptake e.g.
norepinephrine
Treatment of Neurotransmitter Related
Disorders
 Many of the drugs used to treat
neurotransmitter related disorders are similar
to neurotransmitters
 Disorders include
 Alzheimer’s disease
 Parkinson’s disease
 Schizophrenia
 Generalised anxiety disorders
 Depression
Activities
 Case study Alzheimer’s, Parkinson’s and Schizophrenia
What have I learned today?




What are endorphins?
Under what circumstances are endorphins released?
What is dopamine?
What is the common term for where dopamine is
produced in the brain, which is also linked to
addiction?
 What is an agonist?
 What is an antagonist?
 What mode of action do some neurotransmitter
inhibitors use?