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  • JAMA April 23, 2014

    Figure 1: Schematic Illustration of Neurologic Pathways Affected in Parkinson Disease and Sites of Action of Medications for the Treatment of Motor Symptoms

    Available medications to treat the motor symptoms of Parkinson disease act on complex neurologic interactions in the striatum that affect motor activity. Dopaminergic afferents from the substantia nigra, glutamatergic afferents from the cerebral cortex and thalamus, and cholinergic striatal interneurons all converge to influence the activity of the main efferent neurons of the striatum, the medium spiny GABAergic neurons. Levodopa is transported from the peripheral circulation across the blood-brain barrier and is converted centrally to dopamine, replacing the neurotransmitter deficient in Parkinson disease. Outside the blood-brain barrier, in the peripheral circulation, dopamine decarboxylase inhibitors (DDCIs) block the conversion of levodopa to dopamine, and catechol-O-methyltransferase inhibitors (COMTIs) block its degradation to 3-0-methyldopa (3-0MD). In the striatum, levodopa, dopamine agonists, and monoamine oxidase type B inhibitors (MAOBIs) all have dopaminergic effects. Anticholinergic drugs and amantadine act on postsynaptic receptors for other neurotransmitters in the striatum. These neurotransmitters bind to and activate multiple different subtypes of receptors present on the various presynaptic afferents in the striatum, as well as on postsynaptic efferent medium spiny neurons. NMDA indicates N-methyl-d-aspartate.aTolcapone, unlike entacapone, is able to cross the blood-brain barrier and block degradation of levodopa and dopamine.bAmantadine has dopamine releasing effects in addition to affecting NMDA glutamate receptors.
  • JAMA July 11, 2007

    Figure: Novel Therapies Target Myasthenia Gravis

    Researchers are testing new strategies for treating myasthenia gravis, such as inhibiting acetylcholinesterase (above) to boost levels of the neurotransmitter acetylcholine.
  • Future Eye Implants Focus on Neurotransmitters

    Abstract Full Text
    JAMA. 2002; 288(15):1833-1834. doi: 10.1001/jama.288.15.1833
  • Pyre for Pounds

    Abstract Full Text
    JAMA. 2002; 288(10):1226-1226. doi: 10.1001/jama.288.10.1226-JWM20009-3-1
  • JAMA April 10, 2002

    Figure: Decade of Work Shows Depression Is Physical

    A decade of imaging research points to specific, possibly irreversible, changes in brain structures during and after episodes of major depression. Here, transverse PET scans illustrate a recent finding, that brain structures in individuals at the nadir of depression cannot properly listen to the neurotransmitter serotonin (5-hydroxytryptamine [HT]). A series of scans using a radioactive tracer synthesized at the University of Pittsburgh uncovered marked deficiency in 5-HT type 1A receptor activity in depressed individuals. The most pronounced deficits were seen in brain areas critical to emotional stability, including the mesiotemporal cortex (home of the amygdala and the hippocampus) and the midbrain raphe nucleus, which is densely packed with serotonin-producing neurons (Biol Psychiatry. 1999;46:1375-1387). Current antidepressant drugs, such as selective serotonin reuptake inhibitors, appear to compensate for this effect in depressed individuals. (Photo credit: Wayne C. Drevets, MD)
  • Growing Neural Spare Parts

    Abstract Full Text
    JAMA. 1998; 280(7):594-594. doi: 10.1001/jama.280.7.594-JHA80006-4-1
  • Drug and Neurotransmitter Receptors: New Perspectives With Clinical Relevance

    Abstract Full Text
    JAMA. 1989; 261(21):3126-3129. doi: 10.1001/jama.1989.03420210074019
  • Ketamine Minus the Trip: New Hope for Treatment-Resistant Depression

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    JAMA. 2017; doi: 10.1001/jama.2017.12975

    This Medical News article is an interview with psychiatrist Carlos A. Zarate Jr, MD, at the National Institute of Mental Health.

  • Delirium in Older Persons: Advances in Diagnosis and Treatment

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    JAMA. 2017; 318(12):1161-1174. doi: 10.1001/jama.2017.12067

    This narrative review summarizes recent advances in the prevention, diagnosis, and treatment of delirium and highlights critical areas for future research.

  • Chess Study Revives Debate Over Cognition-Enhancing Drugs

    Abstract Full Text
    JAMA. 2017; 318(9):784-786. doi: 10.1001/jama.2017.8114

    This Medical News article explores the nonmedical and medical uses of cognition enhancing drugs.

  • Management of Depression in Older Adults: A Review

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    JAMA. 2017; 317(20):2114-2122. doi: 10.1001/jama.2017.5706

    This review offers guidance on medical and psychotherapeutic treatment options available for older frail patients with depression and who are taking several types of medications.

  • Diagnosis and Treatment of Pituitary Adenomas: A Review

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    JAMA. 2017; 317(5):516-524. doi: 10.1001/jama.2016.19699

    This narrative review discusses the epidemiology, clinical characteristics, diagnosis, and treatment of pituitary adenomas.

  • The Microbiome and Risk for Obesity and Diabetes

    Abstract Full Text
    JAMA. 2017; 317(4):355-356. doi: 10.1001/jama.2016.20099

    This Viewpoint discusses mechanisms by which the human microbiome might influence risk of obesity, type 2 diabetes, and atherosclerosis, and ways in which the microbiome might be manipulated to reduce those risks.

  • The Effect : A New Play Takes on Psychopharmacology, in All Its Human and Scientific Complexity

    Abstract Full Text
    JAMA. 2016; 316(14):1434-1435. doi: 10.1001/jama.2016.14526

    Review of The Effect, a play that features characters in a clinical trial.

  • As Opioid Prescribing Guidelines Tighten, Mindfulness Meditation Holds Promise for Pain Relief

    Abstract Full Text
    JAMA. 2016; 315(22):2385-2387. doi: 10.1001/jama.2016.4875

    This Medical News feature examines mindfulness meditation as a nonpharmacologic approach to managing chronic pain.

  • Flibanserin for Treating Low Sexual Desire in Women

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    JAMA. 2015; 314(12):1312-1312. doi: 10.1001/jama.2015.11769
  • Prevention of Myopia in Children

    Abstract Full Text
    JAMA. 2015; 314(11):1137-1139. doi: 10.1001/jama.2015.10723
  • Pushing the Limits of Human Neuroimaging

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    JAMA. 2015; 314(10):993-994. doi: 10.1001/jama.2015.10229

    This Viewpoint discusses advances in functional neuroimaging technologies that could improve the diagnosis and care of patients and provide new insights into relationships between brain structure and function.

  • Effect of Dextromethorphan-Quinidine on Agitation in Patients With Alzheimer Disease Dementia: A Randomized Clinical Trial

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    JAMA. 2015; 314(12):1242-1254. doi: 10.1001/jama.2015.10214

    This randomized trial assessed the efficacy and safety of combination dextromethorphan-quinidine to manage agitation among patients with probable Alzheimer disease.

  • Medical Marijuana: Is the Cart Before the Horse?

    Abstract Full Text
    JAMA. 2015; 313(24):2431-2432. doi: 10.1001/jama.2015.6407

    This Editorial discusses some of the medical and legal considerations surrounding use of medical marijuana and cannabinoid drugs.