NURS 660 Exam 1 Study Guide - PMHNP

NURS 660 Exam 1 Study Guide - PMHNP.Exam 1 Review Pathways in schizophrenia • Brain imaging shows cerebral atrophy and enlarged fluid filled ventricles, as well as shrinkage in prefrontal cortex, temporal, basal ganglia, and limbic regions like hippocampus. • Five dopamine pathways in the brain. The neuroanatomy of dopamine neuronal pathways in the brain can explain the symptoms of schizophrenia as well as the therapeutic effects and side effects of antipsychotic drugs. Know different pathways in the brain • The nigrostriatal dopamine pathway, which projects from the substantia nigra to the basal ganglia or striatum, is part of the extrapyramidal nervous system and controls motor function and movement. When dopamine is deficient, it can cause parkinsonism with tremor, rigidity, and akinesia/bradykinesia. When DA is in excess, it can cause hyperkinetic movements such as tics and dyskinesias. In untreated schizophrenia, activation of this pathway is believed to be “normal.” • The mesolimbic dopamine pathway projects from the midbrain ventral tegmental area to the nucleus accumbens, a part of the limbic system of the brain thought to be involved in many behaviors such as pleasurable sensations, the powerful euphoria of drugs of abuse, as well as delusions and hallucinations of psychosis. Hyperactivity of dopamine neurons in the mesolimbic dopamine pathway theoretically mediates the positive symptoms of psychosis such as delusions and hallucinations. This pathway is also involved in pleasure, reward, and reinforcing behavior, and many drugs of abuse interact here. • The mesocortical dopamine pathway also projects from the midbrain ventral tegmental area but sends its axons to areas of the prefrontal cortex, where they may have a role in mediating cognitive symptoms (dorsolateral prefrontal cortex, DLPFC) and affective symptoms (ventromedial prefrontal cortex, VMPFC) of schizophrenia. Expression of these symptoms is thought to be associated with hypoactivity of this pathway. • The tuberoinfundibular dopamine pathway projects from the hypothalamus to the anterior pituitary gland and controls prolactin secretion into the circulation. Dopamine inhibits prolactin secretion. In untreated schizophrenia, activation of this pathway is believed to be “normal.”. • The thalamic dopamine pathway arises from multiple sites, including the periaqueductal gray, ventral mesencephalon, hypothalamic nuclei, and lateral parabrachial nucleus, and it projects to the thalamus. Its function is not currently well known but may be involved in sleep and arousal mechanisms by gating information