Talk:Neurodegeneration

Chronic depression as a neurodegenerative disease
User 202.7.77.248, if I understand you correctly, you are saying that there is evidence that chronic depression can, in some cases, be caused by the presence of "glial reduction in the subgenual prefrontal cortex." That finding, however, does not allow us to conclude that depression is always caused by this condition. Nor can we conclude that the glial reduction is the result of disease, nor that it is degenerative. Or am I missing something?

Öngür*, Drevets, and Price state in the conclusion to their study: "We thus have identified a biological marker associated with familial mood disorders that may provide important clues regarding the pathogenesis of these common psychiatric conditions." Clues only. Not facts. Sunray 08:30, 3 November 2005 (UTC)


 * Thanks for contributing to the debate - true - these are clues - however important ones and possible implications should be carefully cosidered before early withdrawel of medication when patients with chronic depression seems better - further studies in risktaking behaviour for this patient group is necessary..

Pjr05, you really need to look into Wikipedia's guidelines for content. Let's start with NPOV. There is a strong precedent that tentative, speculative and otherwise not widely accepted views only need a forum in Wikipedia if they have a large support base. For example, if a significant portion of neurologists or psychiatrists believes that depression may have a neurodegenerative component, then this would require mention both here and on clinical depression. Unfortunately, you have presented no evidence that this is the case; it may be a matter of your personal conviction or even a few people, but that does not make it worthy of inclusion in an encyclopedia.

Please understand that we are not here to censor or suppress information, but like any encyclopedia we need to be careful that what we're presenting actually consists of accepted views. Further studies may lead to the material becoming worthy of inclusion at some point in the future. I hope you understand these considerations, and I also hope this will not deter you from contributing to this project in other ways. JFW | T@lk  14:22, 3 November 2005 (UTC)


 * Dr Wolff - Point taken - thanks for constructive appraoch - I believe there is constructive evidence (animal and human studies - Yale and Wisconson) that demonstrate this - I will endevour to present some of the research - may be in a stub re "research on links between depression and neurodegenerative disease" Peter

Considering the study was performed in 1998, have any other studies been undertaken to validate its findings? JFW | T@lk  22:12, 3 November 2005 (UTC)

Included some studies (on different levels and focus) that indicate neurological degenreation Sapolsky RM The possibility of neurotoxicity in the hippocampus in major depression: a primer on neuron death. Biol Psychiatry. 2000 Oct 15;48(8):755-65. A number of studies indicate that prolonged, major depression is associated with a selective loss of hippocampal volume that persists long after the depression has resolved. This review is prompted by two ideas. The first is that overt neuron loss may be a contributing factor to the decrease in hippocampal volume. As such, the first half of this article reviews current knowledge about how hippocampal neurons die during insults, focusing on issues related to the trafficking of glutamate and calcium, glutamate receptor subtypes, oxygen radical generation, programmed cell death, and neuronal defenses. This is meant to orient the reader toward the biology that is likely to underlie any such instances of neuron loss in major depression. The second idea is that glucocorticoids, the adrenal steroids secreted during stress, may play a contributing role to any such neuron loss. The subtypes of depression associated with the hippocampal atrophy typically involve significant hypersecretion of glucocorticoids, and the steroid has a variety of adverse effects in the hippocampus, including causing overt neuron loss. The second half of this article reviews the steps in this cascade of hippocampal neuron death that are regulated by glucocorticoids.

Kalia M Neurobiological basis of depression: an update. Metabolism. 2005 May;54(5 Suppl 1):24-7. The past 5 years have seen unprecedented advances in our knowledge about the neurobiology of depression. Significant breakthroughs have been made in genomics, imaging, and the identification of key neural systems involved in cognition, emotion, and behavior. In addition, novel targets have been identified for the development of new pharmacological and behavioral treatments. Genetic variations associated with most mental disorders are being identified, and reliable tests for early detection of risk and disease are now on the horizon. New neurobiological concepts have emerged, as they relate to these advances in mental health research such as the serotonin transporter receptor, a genetic variant of which doubles the risk of depression. Brain neurochemicals, including neurotropic factors (implicated in several mental disorders), and anatomical studies involving imaging of the amygdala and the hippocampus and prefrontal cortex are now at the forefront. Several brain neurotransmitters systems: glutamate, gamma -aminobutyric acid, serotonin, norepinephrine, and dopamine have been implicated in depression and mania. These transmitter systems, as well as other neurochemical systems such as membrane-bound signal transduction systems and intracellular signaling systems that modulate gene transcription and protein synthesis, play an important role in the etiology of depression. This new knowledge is expected to provide important clues for the development of selective pharmacological interventions. Neuroimaging studies of depressed patients have shown several abnormalities of regional cerebral blood flow and glucose metabolism--a surrogate of neuronal function--in various brain regions, including the limbic cortex, the prefrontal cortex, the hippocampus, the amygdala, and the anterior cingulate cortex. At this time, a considerable amount of new information is converging--derived from animal models of mood disorders, genetics, basic behavioral research, and neuroscience. It is inevitable that the next step in this progression will be the integration of these basic advances in clinical management and the application of this new information in the context of the depressed patient.

Caetano SC, Fonseca M, Olvera RL, Nicoletti M, Hatch JP, Stanley JA, Hunter K, Lafer B, Pliszka SR, Soares JC Proton spectroscopy study of the left dorsolateral prefrontal cortex in pediatric depressed patients. Neurosci Lett. 2005 Aug 26;384(3):321-6. The dorsolateral prefrontal cortex (DLPFC) plays an essential role in mood regulation and integration of cognitive functions that are abnormal in major depressive disorder (MDD). Few neuroimaging studies have evaluated the still maturing DLPFC in depressed children and adolescents. We conducted single voxel proton magnetic resonance spectroscopy ((1)H MRS) of the left DLPFC in 14 depressed children and adolescents (13.3 +/- 2.3 years old, 10 males) and 22 matched healthy controls (13.6 +/- 2.8 years old, 13 males). Depressed subjects had significantly lower levels of glycerophosphocholine plus phosphocholine (GPC + PC; or choline-containing compounds) and higher myo-inositol levels in the left DLPFC compared to healthy controls. In the depressed subjects, we found significant inverse correlations between glutamate levels and both duration of illness and number of episodes. In healthy controls there was a significant direct correlation between age and glutamine levels, which was not present in the patient group. Lower GPC + PC levels in pediatric MDD may reflect lower cell membrane content per volume in the DLPFC. Increased myo-inositol levels in MDD may represent a disturbed secondary messenger system. GPC + PC and myo-inositol abnormalities further demonstrate the involvement of DLPFC in pediatric MDD.

McEwen BS, Chattarji S Molecular mechanisms of neuroplasticity and pharmacological implications: the example of tianeptine. Eur Neuropsychopharmacol. 2004 Dec;14 Suppl 5S497-502. The hippocampal formation, which expresses high levels of adrenal steroid receptors, is a malleable brain structure that is important for certain types of learning and memory. This structure is also vulnerable to the effects of stress hormones which have been reported to be increased in depressed patients, particularly those with severe depression. The amygdala, a structure that plays a critical role in fear learning, is also an important target of anxiety and stress. Certain animal models of depression involve application of repeated stress. Repeated stress promotes behavioral changes that can be associated with these two brain structures such as impairment of hippocampus-dependent memory and enhancement of fear and aggression, which are likely to reflect amygdala function. At a cellular level, opposite responses in the hippocampus and amygdala are observed, namely, shrinkage of dendrites in hippocampus and growth of dendrites in the lateral amygdala, involving in both cases a remodeling of dendrites. Furthermore, stress-induced suppression of neurogenesis has been noted in dentate gyrus. At a molecular level, the effects of repeated stress in the hippocampus involve excitatory amino acids and the induction of the glial form of the glutamate transporter. Chronic treatment with the antidepressant tianeptine may prevent these effects in hippocampus and amygdala. peter

Replace Creutzfeldt-Jakob disease with transmissible spongiform encephalopathies (TSEs).?
Dear People, Could we replace CJD with the more inclusive term TSE, which also has an extensive Wiki article? thanks Mike Hooten mlhooten(at)gmail.com

Add Shy-Drager syndrome?
I know nothing at all about neurology, so I'll only make a suggestion and let others decide. Should Shy-Drager syndrome be included in the list of neurodegenerative diseases? By chance, I noticed that the Johnny Cash article links to Shy-Drager and describes that syndrom as neurodegenerative. Hult041956 22:31, 17 August 2007 (UTC)

removed multiple sclerosis, added Frontotemporal lobar degeneration
MS has been proven to be an autoimmune disease, thus in medical terms neurodegenerative no longer fits it (the term usually applies to auto-degenerative, loss due to external reasons, like inner skull pressure isn't considered neurodegenerative). as for FTLD, please see http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=600274  —Preceding unsigned comment added by 217.132.28.7 (talk) 17:52, 31 August 2008 (UTC)

redirect
Following discussion at WT:WikiProject Neuroscience, I have redirected this page to Neurodegeneration, which is a substantially stronger article. If anybody has comments or objections, could you please present them at the discussion there? Looie496 (talk) 19:14, 1 February 2010 (UTC)

Move discussion in progress
There is a move discussion in progress on Talk:Neurodegeneration which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 18:18, 14 December 2021 (UTC)