(A+ GUARANTEE) LATEST NURS 660 Exam1 2023-24 QUESTIONS AND EXPLAINED ANSWERS

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 2 Apathy, Anhedonia, Cognitive Blunting, Neuroleptic dysphoria 3 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.