The latest from http://brainblogger.com!
This month’s good news range from promising new therapies to technological advances, while the bad news tell us about damaging side-effects and consequences of diseases, therapies and behaviors. These are personal opinions, presented in no particular order and we welcome your comments and suggestions. If you have come across any interesting studies, let us know in the comment section.
Our monthly roundup starts with a shout out to a notable researcher whose birthday fell on March: Susan Hockfield, neuroscientist and professor of neuroscience at the MIT, born March 24th 1951.
Susan Hockfield is a biologist with a PhD in Anatomy and Neuroscience from the Georgetown University School of Medicine. She was a postdoctoral fellow at the University of California at San Francisco and she then moved to the Cold Spring Harbor Laboratory in New York. Yale University was her next stop, where she served as the William Edward Gilbert Professor of Neurobiology, Dean of the Graduate School of Arts and Sciences (1998-2002), and Provost (2003-2004). In 2004 she became president of MIT, a position she held until 2012.
As a neuroscientist, Susan Hockfield has focused her research on developmental neurobiology, identified a set of proteins whose expression is regulated by neuronal activity early in an animal’s life, and pioneered the use of monoclonal antibody technology in brain research. She also studied glioma, a deadly form of brain cancer, and discovered a gene implicated in the spread of cancer in the brain, providing a link between her research and human health. Read more about her achievements here. Happy birthday, Susan Hockfield!
Multiple sclerosis therapies using autologous haematopoietic stem-cell transplantation
Current multiple sclerosis (MS) therapies are mostly insufficient to treat the severe neurological deficits this disease induces. Intense immunosuppression followed by autologous haematopoietic stem cell transplantation has been tested over the past few years as a possible therapy for severe forms of MS. However, its clinical efficacy is yet to be proved.
In March, Neurology showed us that progress is being made. A phase II clinical trial (assessing the effectiveness and safety of the treatment in a large group of people) compared the effect of this strategy with the effect of immunosuppression followed by mitoxantrone on MS. Mitoxantrone has been used in MS therapy, being effective in slowing the progression of secondary progressive MS and extending the time between relapses in relapsing-remitting MS and progressive relapsing MS. This clinical trial demonstrated that intense immunosuppression followed by autologous haematopoietic stem-cell transplantation can reduce the number of new MS associated lesions as well as the relapse rate; this therapeutical approach was significantly superior to mitoxantrone in reducing MRI activity in severe cases of MS. These are promising results.
Multiple sclerosis therapies using endogenous neural stem cells
Also in the field of MS therapy, a promising alternative therapy is the use of endogenous neural stem cells to promote neuronal regeneration and remyelination, hoping to decrease cognitive disability in MS. A review published in Frontiers in Neuroscience analyses the progresses and the challenges in this field. Although more research is still needed in order to assess its real therapeutic potential, this study highlights the possible role of endogenous neural stem cells in the regeneration of MS lesions.
Cannabinoids for the treatment of stroke
Cannabinoids have been gaining ground as promising neuroprotective agents. The March issue of the Journal of Cerebral Blood Flow and Metabolism published a study reviewing the available data on the effects of cannabinoids in experimental stroke, specifically, on the outcomes of infarct volume, functional scores and survival rate. Overall, it was found that, although they show no effect in the survival rate, cannabinoids may be effective in reducing infarct volume and improve functional outcome in experimental stroke.
Growing new brain tissue
Work published in the March issue of The Journal of Neuroscience shows that brain development in frog embryos can be shaped by changes in the voltage gradients across cell membranes, and that this endogenous bioelectricity is an important factor during brain development. This means that neural cells can communicate over relatively long distances through these bioelectrical signals during development. The authors show that this communication route can be manipulated to stimulate the growth of extra brain tissue, suggesting that voltage modulation may one day be used as a strategy for intervention in certain types of birth defects.
A new device for continuous EEG recording
Non-invasive continuous electroencephalogram (EEG) recording devices have numerous applications as brain-computer interfaces and in medical diagnosis, sleep monitoring, and cognitive control, for example. However, existing continuous EEG recording devices, particularly the hardware components, have many drawbacks associated with their complexity that limit their use. A study published in the Proceedings of the National Academy of Sciences (PNAS) introduces a new soft electronic device that can adapt to the curvature of the ear and withstand normal activities to provide long-term, high-fidelity recording of EEG data.
The enduring effects of the Ebola epidemic
News published this month in Nature draws attention to the fallout of the Ebola outbreak in West Africa. Although this epidemic is fading in most countries, it is still active in a few, such as in Guinea and Sierra Leone, for example. And even after the disease is contained, its impact on mental health may remain for years. As Nature’s article highlights, survivors face traumatic memories, extreme anxiety, rejection by society, and grief over lost relatives. It would be desirable that the “First World” did not forget about this ongoing problem.
Another article in the same issue of Nature also highlights an additional consequence of the Ebola epidemic: its impact on maternal health. Pregnancy seems to increase the vulnerability to Ebola’s effects, and babies born to infected women are unlikely to survive. Check these two articles for more information.
ADHD may be a risk factor for premature death
Work just made available online in The Lancet in March brings us some bad news about attention deficit hyperactivity disorder (ADHD). This was a massive cohort study, with up to 32 years follow-up, using medical registers of Denmark to follow 1.92 million people, of whom around 32,000 had ADHD. The authors found that individuals with ADHD had increased mortality rates, especially those diagnosed with ADHD in adulthood when compared to those diagnosed in childhood. This suggests that ADHD persisting into adulthood may represent a more severe form of the disorder. The main causes of death in individuals with ADHD were mostly unnatural, with accidents being the most common.
Anticholinergic drugs and dementia
Anticholinergic drugs are used in the treatment of various conditions. The most commonly used drugs with anticholinergic actions include tricyclic antidepressants, antihistamines, and bladder antimuscarinics. The continued use of anticholinergic drugs is associated with cognitive impairment, but this effect is considered reversible after discontinuation of anticholinergic therapy. However, a possible association between anticholinergics and an increased risk for dementia has been suggested.
A prospective study published in JAMA Internal Medicine examined the association between anticholinergic use and incident dementia. The authors found that a higher cumulative use of anticholinergic drugs was indeed associated with an increased risk for dementia and Alzheimer’s disease.
Cannabis and mental health
The risk of adverse effects associated with drug use generally depends on the potency of the drug and the frequency of consumption. Since there is a well-known link between cannabis use and the development of schizophrenia-like psychotic disorders, a study published in The Lancet Psychiatry investigated how the frequent use of high-potency cannabis could affect this association. The patterns and types of cannabis used between patients with first-episode psychosis and a control group were compared. There was a significantly higher risk of having a psychotic disorder for users of skunk-like cannabis, a more potent strain of cannabis, compared with those who never consumed. Daily use of skunk-like cannabis conferred the highest risk of psychotic disorders. This is bad news for cannabis consumers, but it is better to be fully aware of the long-term risks.
Binge drinking and cognitive impairment
Adolescence is a key developmental period for cognitive faculties. Everyone is well aware that binge drinking is common during adolescence, and it is highly likely that this practice can impact brain maturation. Experimental research published in Frontiers in Neuroscience showed that intermittent administration of high doses of ethanol to adolescent rats reduced neurogenesis in the hippocampus that persisted during abstinence into adulthood, as well as an increase in cell death. Possible consequences of binge drinking in adolescence include altered adult cognitive and emotive function.
Dalsgaard S, Østergaard SD, Leckman JF, Mortensen PB, & Pedersen MG (2015). Mortality in children, adolescents, and adults with attention deficit hyperactivity disorder: a nationwide cohort study. Lancet PMID: 25726514
Di Forti, M., Marconi, A., Carra, E., Fraietta, S., Trotta, A., Bonomo, M., Bianconi, F., Gardner-Sood, P., O’Connor, J., Russo, M., Stilo, S., Marques, T., Mondelli, V., Dazzan, P., Pariante, C., David, A., Gaughran, F., Atakan, Z., Iyegbe, C., Powell, J., Morgan, C., Lynskey, M., & Murray, R. (2015). Proportion of patients in south London with first-episode psychosis attributable to use of high potency cannabis: a case-control study The Lancet Psychiatry, 2 (3), 233-238 DOI: 10.1016/S2215-0366(14)00117-5
England TJ, Hind WH, Rasid NA, & O’Sullivan SE (2015). Cannabinoids in experimental stroke: a systematic review and meta-analysis. Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 35 (3), 348-358 PMID: 25492113
Gray SL, Anderson ML, Dublin S, Hanlon JT, Hubbard R, Walker R, Yu O, Crane PK, & Larson EB (2015). Cumulative use of strong anticholinergics and incident dementia: a prospective cohort study. JAMA internal medicine, 175 (3), 401-7 PMID: 25621434
Hayden EC (2015). Maternal health: Ebola’s lasting legacy. Nature, 519 (7541), 24-6 PMID: 25739614
Mancardi GL, Sormani MP, Gualandi F, Saiz A, Carreras E, Merelli E, Donelli A, Lugaresi A, Di Bartolomeo P, Rottoli MR, Rambaldi A, Amato MP, Massacesi L, Di Gioia M, Vuolo L, Currò D, Roccatagliata L, Filippi M, Aguglia U, Iacopino P, Farge D, Saccardi R, ASTIMS Haemato-Neurological Collaborative Group, On behalf of the Autoimmune Disease Working Party (ADWP) of the European Group for Blood and Marrow Transplantation (EBMT), & ASTIMS Haemato-Neurological Collaborative Group On behalf of the Autoimmune Disease Working Party ADWP of the European Group for Blood and Marrow Transplantation EBMT (2015). Autologous hematopoietic stem cell transplantation in multiple sclerosis: A phase II trial. Neurology, 84 (10), 981-8 PMID: 25672923
Michailidou I, de Vries HE, Hol EM, & van Strien ME (2014). Activation of endogenous neural stem cells for multiple sclerosis therapy. Frontiers in neuroscience, 8 PMID: 25653584
Norton JJ, Lee DS, Lee JW, Lee W, Kwon O, Won P, Jung SY, Cheng H, Jeong JW, Akce A, Umunna S, Na I, Kwon YH, Wang XQ, Liu Z, Paik U, Huang Y, Bretl T, Yeo WH, & Rogers JA (2015). Soft, curved electrode systems capable of integration on the auricle as a persistent brain-computer interface. Proceedings of the National Academy of Sciences of the United States of America, 112 (13), 3920-5 PMID: 25775550
Pai VP, Lemire JM, Paré JF, Lin G, Chen Y, & Levin M (2015). Endogenous Gradients of Resting Potential Instructively Pattern Embryonic Neural Tissue via Notch Signaling and Regulation of Proliferation. The Journal of neuroscience : the official journal of the Society for Neuroscience, 35 (10), 4366-85 PMID: 25762681
Reardon S (2015). Ebola’s mental-health wounds linger in Africa. Nature, 519 (7541), 13-4 PMID: 25739606
Vetreno RP, & Crews FT (2015). Binge ethanol exposure during adolescence leads to a persistent loss of neurogenesis in the dorsal and ventral hippocampus that is associated with impaired adult cognitive functioning. Frontiers in neuroscience, 9 PMID: 25729346
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