NURS 660 Exam 1 LATEST UPDATE 2023 QUESTIONS AND EXPLAINED ANSWERS |AGRADE
1. Identify the emerging neurobiological hypothesis of schizophrenia.
o The hypothesis: (focus on the most detail with the Dopamine Theory)
The only pharmacological treatment that we have are dopamine (D2 receptors) and ...
NURS 660 Exam1 LATEST UPDATE 2023
QUESTIONS AND EXPLAINED
ANSWERS|AGRADE
1. Identify the emerging neurobiological hypothesis of schizophrenia.
o The hypothesis: (focus on the most detail with the Dopamine Theory)
❖ The only pharmacological treatment that we have are dopamine (D2
receptors) and serotonin (5HT2A)
❖ Dopamine Theory
▪ Hyperactive dopamine at D2 receptors in the mesolimbic
pathway
In the mesolimbic pathway is responsible for the positive
symptoms; the hypoactivity is responsible for the negative
▪ Mesolimbic pathway it’s overactive dopamine receptors or
overactive dopamine on the dopamine receptors in mesolimbic
pathways but it is also hypoactive dopamine at the D2 receptors
in the mesocortical pathway
▪ Most detailed knowledge about this theory because that has been
our foundational understanding of schizophrenia up until the very
recent past so the other two, we don’t have as much detail about.
But the other two just give us a much fuller understanding as far
as why the Dopamine Theory happened in the first place.
❖ Glutamate Theory
▪ Hypoactive dopamine at N-Methyl-D-Asperate (NMDA) receptor
▪ NMDA receptors are hypofunctioning and because of that, it leads
to hyperactive dopamine in the mesolimbic pathway and
hypoactive dopamine in the mesocortical pathway.
▪ The NMDA receptor is on the GABA interneurons
▪ Emerging one
❖ Serotonin Theory
▪ Hyperactive dopamine at the 5HT2A receptors in the
mesocortical pathway
5HT2A receptors are overly active
In the mesocortical pathway is responsible for the negative
symptoms
▪ 5HT2A receptors are hyperfunctioning, which leads to over
functioning or overactive dopamine on those receptors in them
as a mesolimbic pathway and hypoactive dopamine receptors in
that mesocortical pathway
o Positive symptoms
❖ Delusions, Hallucinations
o Negative symptoms
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,2. Identify the different dopamine pathways and what role each pathway
plays in relation to schizophrenia/psychosis and treatment.
o Dopamine Pathways – 2 pathways are related to pathophysiology
(nigrostriatal & tuberoinfundibular) and 2 pathways are responsible for signs
& symptoms of schizophrenia (mesolimbic & mesocortical)
❖ Mesolimbic
❖ Mesocortical
❖ Nigrostriatal
❖ Tuberoinfundibular
o 2 are responsible for the symptoms, the signs & symptoms of schizophrenia
(positive/negative signs)
❖ Mesolimbic & Mesocortical
▪ How are the positive/negative manifesting in the mesolimbic area
and mesocortical area? What dopamine is doing, and what’s the
difference?
Mesolimbic Pathway
➢ Hyperactive
➢ Looney pathway, where too much dopamine is
happening
➢ The way the medications will work is by blocking the
dopamine, can’t get so excessive
➢ You can think of L as lunacy/looney because that is
where the positive symptoms are. The positive
symptoms are if you saw that individual in the
street, you would think they are positively insane
because they might be hearing voices, talking to
themselves, or responding to internal stimuli.
➢ Negative symptoms are harder to catch because
the person is more withdrawn, not social, they tend
to not have a lot of emotional expressions
❖ Mesocortical Pathway
▪ Hypoactive
▪ What is dopamine doing in that pathway as far as negative
symptoms?
Too little
Blocking dopamine will make a bad situation worse like
anhedonia
o These drugs we have currently, do a really good job in reducing the positive
symptoms but because these drugs do not have selectivity for just the one
pathway that is involved in the positive symptoms, they tend to make the
bad situation being too little dopamine on that cortical pathway even worse.
Thus far there is not a specific agent that treats the negative symptoms. The
newer meds have a tendency not to make the problem worse but do not fix
the problem either.
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, o The other 2, what is involved in collateral damage of the treatment that we
administer for schizophrenia
❖ Nigrostriatal Pathway
❖ Tuberoinfundibular Pathway
❖ What happens to the nigrostriatal pathway and the tuberoinfundibular
pathway when we are treating schizophrenia? Under normal
circumstances individuals with schizophrenia there is nothing wrong
with schizophrenia. When we throw our treatments at them, is when we
cause problems. What kinds of problems happen we have when we
block dopamine in those pathways?
▪ Nigrostriatal
Has to do with extrapyramidal systems like motor function,
Parkinsonian type activity like rigidity and tremors
Too little dopamine causes movement disorders like
Parkinson’s disease, akathisia, and dystonia
Too much dopamine causes hyperkinetic movementdisorders
like chorea, dyskinesias, and tics
Chronic blockade of D2 receptors can lead to tardive dyskinesia
▪ Tuberoinfundibular
When dopamine is blocked, prolactin levels rise
Increased prolactin level (hyperprolactinemia)
➢ Gynecomastia – breast enlargement of breast
development
➢ Amenorrhea – loss of menstrual periods
➢ Galactorrhea – breast secretions
o Tip to help remember:
❖ Nigrostriatal – think “stride” because this area impacts movement.
When we don’t move, we get stiff and sluggish. Decreased dopamine in
this area causes Parkinsonism.
❖ Mesolimbic – think four limbs like a plus sign. Too much dopamine in
this area causes positive symptoms.
❖ Mesocortical – think about the core of who you are (emotions).
Decreased dopamine in this area causes depression (and negative
symptoms)
❖ Tuberoinfundibular – think about infants depending on lactation.
Blocked dopamine causes too much prolactin.
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