NURS 660 Exam 1 LATEST UPDATE 2023 QUESTIONS AND EXPLAINED ANSWERS |AGRADE

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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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❖ Apathy, Anhedonia, Cognitive Blunting, Neuroleptic dysphoria

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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 tardivedyskinesia

▪ 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.