Lecture 2 Flashcards
What are models used for?
To explain
Origins of abnormal behaviour
How to treat it
How to prevent it
List 4 aeitological
Genetics
Biochemistry
Neuroanatomy
Endocrine system
What are the four studies of gene-environment interaction?
- The pedigree method
- Classical twin design
- Adoption studies
- Molecular genetics
The pedigree method
Proband (person diagnosed with the disorder) identified
and then it is looked at how prevalent is the disorder within their family.
It’s tricky because families share environments, so it is difficult to attribute disorder to genetics (nature) of shared environment (nurture).
The classical twin studies
Looking at comparing concordance rates (the likelihood that both twins have that disorder) for monozygotic (identical) and diazygotic (fraternal) twins
Adoption Studies
Compares the concordance of a disorder in adopted children to
- their biological relatives
- their adoptive relatives
Molecular genetics
- Candidate gene studies
- Is one allele (variant of a gene) is that more frequently seen in people with the disorder than in people without the disorder? - Genome wide association studies
- Assess common variation across the entire genome
- Disorders are typically polygenic (influenced by multiple genes) as well as environmental factors
How does information transmitted through a neuron?
Information is received by the dendrites which is then transmitted down the axon (trunk), finally reaching the axon terminal, where messages are sent out to other neurons. The axon terminal is separated from other neurons via a synapse ( a small gap filled with fluid). Here, information is transmitted chemically through neurotransmitters, which are released into the synapse and received at the receptors on the dendrites of another neuron.
Biochemistry as aeitiology
- What do most drug therapies do?
- What is the overall hypothesis?
Most drug therapies look at INCREASING or DECREASING the activity of specific neurotransmitters.
Overall hypothesis is that people with mental disorders either have an excess or deficit in neurotransmitters.
Name the 4 different neurotransmitter systems?
- Serotonin
- GABA
- Noradrenaline
- Dopamine
What does serotonin do?
Serotonin regulates behaviour, mood and thought processes
What is low serotonin actiivity associated with?
Aggression
Suicide
Impulsive overeating
Hyper-sexual behaviour
What drugs primarily affect the serotonin system?
Tricyclic antidepressants
Serotonin specific reuptake inhibitors (e.g., Prozac)
- This means there is more of that neurotransmitter left
in the synapse.
What does GABA do?
Inhibits a variety of behaviours and emotions
Reduces overall arousal (anxiolytic effects = reduces anxiety)
What makes attaching GABA to the receptors of specialised neurons easier?
Benzodiazepines
What secretes Noradrenaline (aka Norephinephrine)?
the adrenal glands
Which circuits in the CNS is noradrenaline implicated to be?
- Hindbrain - in an area that control basic bodily functions such as respiration
- Circuit which influences our fight or flight responses
Why does dopamine influence many of the same behaviours as serotonin?
Because dopamine circuits merge and cross with serotonin circuits
What is dopamine responsible for?
Relays messages to control movements, moods, thought processes
What are the main structures of the brain and describe their functions?
Hindbrain
- Involved in sustaining life, regulation of sleep
Mid-brain
- Regulation of some motor activities (fighting and sex) and sleep
Forebrain
- Site of most sensory, emotional, and cognitive functioning (limbic system falls in with forebrain)
What does damage to the reticular activating system in the mid-brain lead to?
Leads to disturbances in sexual behaviour, aggression and sleep
What does damage to the orbitofrontal cortex lead to?
Leads to disinhibited behaviour (lack of impulse control)