Commentary: Critical role of JSAP1 and JLP in axonal transport in the cerebellar Purkinje cells of mice
Axonal transport is essential for the development, function, and survival of neurons, and impaired axonal transport has been implicated in many neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. To date, however, how axonal transport is regulated, and how defective transport leads to neurodegeneration, remain largely unknown. This study by Sato et al. shows that the loss of both JSAP1 and JLP in the cerebellar Purkinje cells (PCs) of mice causes axonal dystrophy followed by gradual, progressive PC degeneration. This study also suggests that JSAP1 and JLP regulate kinesin-1-dependent axonal transport in the brain with functional redundancy, which prevents axonal degeneration and subsequent neuronal death. There is increasing evidence that in neurodegenerative diseases, axonal degeneration precedes neuronal cell death. Thus, elucidating the mechanisms of axonal degeneration may provide promising targets for therapeutic intervention. The JSAP1-null, JLP-null mouse generated in this study may provide a useful animal model for studying the molecular basis of axonal degeneration in neurodegenerative diseases, and for developing therapeutic drugs for these diseases.DOI: 10.29245/2572.942X/2016/8.1095 View / Download Pdf
Michaela F. George, PhD1*, Calliope B. Holingue, MPH1*, Farren B.S. Briggs, PhD, ScM2, Xiaorong Shao, MA1, Kalliope H. Bellesis3, Rachel A. Whitmer, PhD3, Catherine Schaefer, PhD3, Ralph HB Benedict, PhD4, Lisa F. Barcellos, PhD, MPH1,3,51Division of Epidemiology, Genetic Epidemiology and Genomics Laboratory, School of Public Health, University of California, Berkeley, CA, USA
2Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
3Kaiser Permanente Division of Research, Oakland, CA, USA
4Jacobs MS Center, SUNY Buffalo School of Medicine, Buffalo, NY, USA
Cognitive impairment is common in multiple sclerosis (MS), and affects employment and quality of life. Large studies are needed to identify risk factors for cognitive decline. Currently, a MS-validated remote assessment for cognitive function does not exist. Studies to determine feasibility of large remote cognitive function investigations in MS have not been published.
To determine whether MS patients would participate in remote cognitive studies. We utilized the Modified Telephone Interview for Cognitive Status (TICS-M), a previously validated phone assessment for cognitive function in healthy elderly populations to detect mild cognitive impairment. We identified factors that influenced participation rates. We investigated the relationship between MS risk factors and TICS-M score in cases, and score differences between cases and control individuals.
The TICS-M was administered to MS cases and controls. Linear and logistic regression models were utilized.
11.5% of eligible study participants did not participate in cognitive testing. MS cases, females and individuals with lower educational status were more likely to refuse (p<0.001). Cases who did complete testing did not differ in terms of perceived cognitive deficit compared to cases that did participate. More severe disease, smoking, and being male were associated with a lower TICS-M score among cases (p<0.001). The TICS-M score was significantly lower in cases compared to controls (p=0.007).
Our results demonstrate convincingly that a remotely administered cognitive assessment is quite feasible for conducting large epidemiologic studies in MS, and lay the much needed foundation for future work that will utilize MS-validated cognitive measures.DOI: 10.29245/2572.942X/2016/8.1084 View / Download Pdf
Karen E. Lee, Mahendra T. Bhati, Casey H. Halpern*
Deep brain stimulation (DBS) has proven to be an effective treatment for neurologic disorders such as Parkinson’s disease, and is currently being investigated as a therapy for psychiatric diseases such as addiction, major depressive disorder, and obsessive compulsive disorder. In this commentary, we review and discuss the findings presented in the Letter to the Editor entitled “Attitudes towards treating addiction with deep brain stimulation,” written by Ali et al1. The survey presented in this Letter reported general approval for examining the effects of DBS on addictive disorders in a clinical trial, but highlighted critical areas of concern including informed consent, patient autonomy, appropriate medical practice, passing of clinical trial milestones, and implications on law enforcement.DOI: 10.29245/2572.942X/2016/8.1093 View / Download Pdf
Commentary: Ginkgo Biloba for Mild Cognitive Impairment and Alzheimer 's disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Guoyan Yang1,2, Dennis Chang1, and Jianping Liu2*
Background: Ginkgo biloba is a natural medicine used for cognitive impairment and Alzheimer’s disease.
Methods: This is a commentary on a systematic review that we conducted to evaluate the effectives and safety of Ginkgo biloba in treating mild cognitive impairment or Alzheimer’s disease.
Results: 21 articles with 2608 patients met the inclusion criteria. The general methodological quality of included studies was moderate to poor. Compared with conventional medicine alone, Ginkgo biboba in combination with conventional medicine was superior in improving Mini-Mental State Examination (MMSE) scores at 24 weeks for patients with Alzheimer’s disease (MD 2.39, 95% CI 1.28 to 3.50, P<0.0001) and mild cognitive impairment (MD 1.90, 95% CI 1.41 to 2.39, P<0.00001), and Activity of Daily Living (ADL) scores at 24 weeks for Alzheimer’s disease (MD -3.72, 95% CI -5.68 to -1.76, P=0.0002). When compared with placebo or conventional medicine in individual trials, Ginkgo biboba demonstrated similar but inconsistent findings. Adverse events were mild.
Conclusion: Ginkgo biloba is potentially beneficial for the improvement of cognitive function, activities of daily living, and global clinical assessment in patients with mild cognitive impairment or Alzheimer’s disease. However, due to limited sample size, inconsistent findings and methodological quality of included trials, more research are warranted to confirm the effectiveness and safety of Ginkgo biloba in treating mild cognitive impairment and Alzheimer’s disease.DOI: 10.29245/2572.942X/2016/8.1083 View / Download Pdf
COMMENTARY: Dementia after Three Months and One Year from Stroke: New Onset or Previous Cognitive Impairment?
DOI: 10.29245/2572.942X/2016/8.1092 View / Download Pdf
Salvatore Caratozzolo*, Andrea Scalvini, Francesco Lanfranchi, Silvia Pelizzari, Marina Zanetti, Luca Rozzini, Alessandro Padovani
Blood pressure variability and hemorrhagic transformation after intravenous thrombolysis in acute ischemic stroke
Hanna Choi, MD; Seo Young Choi, MD; Jae Guk Kim, MD; Sung-Yeon Sohn, MD; Do-Hyung Kim, MD; Soo Joo Lee, MD, PhD*Department of Neurology, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Republic of Korea
The effectiveness of intravenous tissue plasminogen activator (t-PA) is well established in hyperacute ischemic stroke. Despite its efficacy, spontaneous intracranial hemorrhage after t-PA is a severe complication associated with poor prognosis. We evaluated the role of blood pressure (BP) and BP variability, measured before and after injection of t-PA within 24 hours. Herein, 116 patients were enrolled in this study. BP (systolic blood pressure, diastolic blood pressure, and pulse pressure) were recorded before t-PA and every hour after t-PA for 24 hours. The BP profiles were characterized by initial, mean, maximum (max), minimum (min), max-min, and standard deviation (sd). The intracranial hemorrhage was assessed via computed tomography, 24-36 hours after injection of t-PA. The hemorrhagic transformation was classified using clinical and radiological criteria as follows: hemorrhagic transformation (HT), parenchymal hemorrhage (PH), and symptomatic hemorrhage (SH). The intracranial hemorrhage occurred as follows: HT 25.52% (n=25), PH 10.81% (n=12), SH 3.60% (n=4). The PPsd during the 24-hour period post-injection (24h PPsd) was significantly higher in patients with HT (14.57±0.76 vs. 11.84±0.39, 95% confidence interval [CI] 1.07-4.40, p<0.001) and PH (16.74±4.17 vs. 11.93±3.48, 95% CI 2.65-6.97, p<0.001). The odds ratio per 5 mmHg of 24h-PPsd was 2.41 (95% CI 1.23-4.72) in HT and 4.76 (95% CI 1.60-12.17) in PH. The variability in pulse pressure during the first 24 hours may be associated with hemorrhagic transformation after thrombolytic therapy with t-PA in hyperacute infarction.DOI: 10.29245/2572.942X/2016/8.1085 View / Download Pdf
Ischemic stroke is caused by interruption or significant impairment of blood supply to the brain, which leads to a cascade of metabolic and molecular alterations resulting in functional disturbance and morphological damage. The changes in regional cerebral blood flow and in regional metabolism can be assessed by radionuclide imaging, especially single photon emission tomography (SPECT) and positron emission tomography (PET). SPECT and PET have broadened our understanding of flow and metabolic thresholds critical for maintenance of brain function and morphology: PET was essential in the transfer of the concept of the penumbra to clinical stroke and thereby had a great impact on developing treatment strategies. Receptor-ligands can be applied as early markers of irreversible neuronal damage and can predict the size of the final infarcts, which is important for decisions of invasive therapy in large (“malignant”) infarction. With SPECT and PET the reserve capacity of blood supply can be tested in obstructive arteriosclerosis, which is essential for planning interventions. The effect of a stroke on surrounding and contralateral primarily not-affected tissue can be investigated helping to understand symptoms caused by disturbance in functional networks. Activation studies are useful to demonstrate alternative pathways to compensate for lesions and to test the effect of rehabilitative therapy. Radioisotope studies help to detect neuroinflammation and its effect on extension of tissue damage. Despite the limitations of broad clinical application of radionuclide imaging, this technology has a great impact on research in cerebrovascular diseases and still has various applications in the management of stroke. In this short review the contributions of PET- and SPECT-studies to the understanding of the pathophysiology of ischemic stroke are described.DOI: 10.29245/2572.942X/2016/8.1087 View / Download Pdf
Wang Liang1, Xu Min2, Sun Yiming3, Zhang Cheng1*
Objective: To report a misdiagnosed case in order to avoid similar misdiagnosis of atypical juvenile dermatomyositis as muscular dystrophy in neurological clinics.
Methods: The process of misdiagnosis was first described. Thereafter, the patient’s diagnosis and treatment effect at the six-month follow-up were evaluated, and reported here.
Results: The patient presented an atypical course of juvenile dermatomyositis. The rashes, which mainly presented as erythema and wheals, were subsequently followed by the appearance of muscle weakness. However, the rashes were inconspicuous at first consult. The misdiagnosis of Duchenne muscular dystrophy was made due to the age of onset, distribution of muscle weakness, a high creatine kinase level, and other serum enzymatic changes. Upon further analysis, however, a diagnosis of juvenile dermatomyositis was definitively confirmed and the disease was controlled following systematic treatment for five months.
Conclusion: Although atypical juvenile dermatomyositis has a manifestation similar to that of muscular dystrophy, the considerations outlined in this case report will be helpful to avoid similar misdiagnosis.DOI: 10.29245/2572.942X/2016/7.1072 View / Download Pdf
Anika M. Helferich1, Pamela J. McLean2, Jochen H. Weishaupt1 and Karin M. Danzer1*1Department of Neurology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
2Mayo Clinic, Jacksonville, Florida, USA
Alpha-synuclein and Cu, Zn superoxide dismutase (SOD1) are both aggregation-prone proteins that are associated with Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS), respectively. Recently, we showed that alpha-synuclein interacts with SOD1 in various cell types and tissues. Using a cell culture model, we also found that alpha-synuclein nucleates the polymerization of SOD1. Here, we discuss the current literature regarding their interaction and their co-localization in aggregates of human post-mortem tissue. Furthermore we comment on the reported alpha-synuclein-induced SOD1 polymerization in terms of cross-seeding effects in neurodegeneration.DOI: 10.29245/2572.942X/2016/7.1065 View / Download Pdf
Extracellular uridine diphosphate-mediated microglial inflammation in a mouse model of Sandhoff disease
Eri Kawashita1, Daisuke Tsuji2, Kohji Itoh2*
Sandhoff disease (SD) is an inherited lysosomal storage disease caused by a β-hexosaminidase deficiency involving excessive accumulation of undegraded substrates, including GM2 ganglioside, which leads to neurological symptoms, such as mental retardation, spasms and quadriplegia. Macrophage inflammatory protein-1α (MIP-1α) is a crucial factor for microglia-mediated neuroinflammation in the onset or progression of SD. However, there was no therapeutic approach to control the abnormal production of MIP-1α in the brain of SD, and the mechanisms underlying the MIP-1α production by microglia, especially the transmitter-mediated production, remains unclear.
Extracellular nucleotides, including uridine diphosphate (UDP), are leaked by injured or damaged neurons. It has been shown that the nucleotide leakage activates microglia to trigger chemotaxis, phagocytosis, macropinocytosis and cytokine production, suggesting that extracellular nucleotides may be important neurotransmitters for microglia to regulate their functions physiologically and pathologically.
In the present study, we review the essential roles of extracellular nucleotides in the microglial functions and the UDP-enhanced MIP-1α production by microglia in SD model mice, providing a potential therapeutic approach for SD.DOI: 10.29245/2572.942X/2016/7.1074 View / Download Pdf
Neuropathies of Stuve-Wiedemann Syndrome due to mutations in leukemia inhibitory factor receptor (LIFR) gene
Alexandra E. Oxford, Cheryl L. Jorcyk, Julia Thom Oxford*
Stüve-Wiedemann syndrome (STWS; OMIM #610559) is a rare disease that results in dysfunction of the autonomic nervous system, which controls involuntary processes such as breathing rate and body temperature. In infants, this can result in respiratory distress, feeding and swallowing difficulties, and hyperthermic episodes. Individuals may sweat excessively when body temperature is not elevated. Additionally, individuals have reduced ability to feel pain and may lose reflexes such as the corneal reflex that normally causes one to blink, and the patellar reflex resulting in the knee-jerk. STWS usually results in infant mortality, yet some STWS patients survive into early adulthood. STWS is caused by a mutation in the leukemia inhibitory factor receptor (LIFR) gene, which is inherited in an autosomal-recessive pattern. Most LIFR mutations resulting in STWS cause instability of the mRNA due to frameshift mutations leading to premature stop codons, which prevent the formation of LIFR protein. STWS is managed on a symptomatic basis as no treatment is currently available.DOI: 10.29245/2572.942X/2016/7.1068 View / Download Pdf
Commentary: A novel infection- and inflammation-associated molecular signature in peripheral blood of myasthenia gravis patients
Claudia Barzago1, Pia Bernasconi1, Raffaele A. Calogero2, Carlo Antozzi1, Francesca Zolezzi3, Renato Mantegazza1# and Lucia Mori4*
Early-onset acetylcholine receptor-positive myasthenia gravis is the most studied and better-characterized clinical subgroup of myasthenia gravis. Here we discuss the results of the first comprehensive and unbiased transcriptome sequencing analysis performed on circulating cells of a clinically homogeneous cohort of patients affected by this disease form.DOI: 10.29245/2572.942X/2016/7.1081 View / Download Pdf
Aaron Dadas1,2 Jolewis Washington4, Damir Janigro1,3*
The brain is a complex system that requires continual regulation of parenchymal pressure, osmolarity, and waste removal for optimal function; despite this, human brain lacks any obvious extension of lymphatic circulation for moderating fluid and waste regulation. We recapitulate herein a recent analysis of proteinaceous waste deposition in the human brain, its observed route of clearance, and the implications of abnormal accumulation along this clearance pathway as a potential mechanism of neurological diseases. This study uncovered an analogous staining pattern of cerebral phosphorylated tau in temporal lobe epilepsy (TLE) and chronic traumatic encephalopathy (CTE). Regardless of the underlying physiopathology, p-tau elimination occurred via circulation through the perivenous space, as predicted by a glymphatic route of clearance. Remarkably, we demonstrated that p-tau is associated with a neurological disease that can develop independent of head trauma, since in both CTE and TLE: 1) Extracellular p-tau followed unidirectional, fluid-driven pathways that led toward the space bordering large (>100 µm diameter) blood vessels; 2) Tau-positive staining occurred within astroglial cells adjacent to blood vessels, which signified transcellular transport of p-tau as a potential secondary efflux route; 3) P-tau frequently appeared clustered within the perivenous space. This waste aggregation bears significant implications in the disruption of interstitial fluid circulation, which may contribute to exacerbation of disease states. A better understanding of waste elimination in the human brain may prove significant as a therapeutic target to improve parenchymal fluid circulation, and consequently, mitigate the hydrostatic, osmotic and oncotic imbalances that often cause or exacerbate brain diseases.DOI: 10.29245/2572.942X/2016/7.1082 View / Download Pdf
Víctor Danelon1, Andrea B. Cragnolini1, Daniel Masco1*
Several neurological conditions share a characteristic feature: an increase in intracellular calcium levels ([Ca2+]i). It has been demonstrated that calcium influx induces changes ranging from an increase in the expression levels of several genes to the activation of proteases such as calpains. Calpains are a family of Ca2+-dependent non-lysosomal cysteine proteases, whose substrates include several proteins that play critical roles in several cellular functions including synaptic plasticity and neuronal apoptosis.
TrkB is a type of tyrosine related kinase receptor that can promote neuronal survival and differentiation upon ligand binding. It has been recently shown that in several neurological diseases, the level of full-length TrkB protein decreases before the onset of neuronal death due to one of two different processes: a) a reverse regulation of TrkB isoforms mRNA, or b) calpain-mediated processing of TrkB full-length, which yields a truncated form of TrkB (Tc-TrkB). Because the most notorious feature of calpain proteolytic activity is that the products of calpain-mediated cleavage may have biological activity, here we review the hypotheses by which calpain-generated isoform Tc-TrkB may perform biological functions.DOI: 10.29245/2572.942X/2016/7.1076 View / Download Pdf
Comment: New potential pharmacological functions of Chinese herbal medicines via regulation of autophagy: the search of reliable pharmaceutical candidates for chronic disorders therapy
Simon Wing Fai Mok, Vincent Kam Wai Wong, Betty Yuen Kwan Law*
Chronic diseases are the leading causes of physical impairments and mortality in the world. The functional role of autophagy in maintaining cellular homeostasis implies that the molecular machinery is a compelling pharmaceutical target for such disorders involving overall body imbalance. Therefore, autophagy modulators appeared to be the ideal source for hunting of novel and effective pharmaceutical interventions. Law et al., have performed a systematic review on more than 30 different Chinese herbal medicine (CHM)-derived bioactive compounds capable of regulating autophagy activity. The successful experimental and clinical applications of these compounds which have not been previously documented have been discussed. Notably, most of the reported novel applications are associated with chronic dysfunctions.DOI: 10.29245/2572.942X/2016/7.1070 View / Download Pdf
John R. Zuniga1*, Tara F. Renton2
In the absence of effective non-surgical methods to permanently resolve neuropathic pain involving the lip, chin, or tongue following inferior alveolar and/or lingual nerve injury, microsurgery of these nerves has been a recommended modality. In two ambispective clinical trials, we demonstrated that phenotypic differences exist between individuals with neuropathic pain and those without neuropathic pain of the trigeminal nerve. In those without neuropathic pain before microsurgery there was a 2% incidence of neuropathic pain after microsurgery whereas there was a 67% incidence of neuropathic pain after microsurgery, some reporting an increase in pain levels, when neuropathic pain was present before microsurgery. The recurrence of neuropathic pain after trigeminal microsurgery is likely multifactorial and might not depend on factors that normally affect useful or functional sensory recovery in those who have no neuropathic pain. These results indicate that the understanding of post-traumatic trigeminal neuropathic pain is incomplete. Predictive outcomes of treatment will probably improve when the etiology is better defined to allow mechanistic or target-/site-specific treatment. Until then, non-surgical treatment for post-traumatic trigeminal neuropathic pain remains a safer option. Risk factors have been identified for patients developing chronic post -surgical pain due to post-traumatic neuropathy. These include psychological, medical, and age related factors. The best management may lie in preoperative screening and avoidance of elective surgery for high risk patients as the prevention of post-traumatic trigeminal neuropathic pain in the absence of effective medical or surgical interventions.DOI: 10.29245/2572.942X/2016/7.1080 View / Download Pdf
Milena A. Gianfrancesco and Lisa F. Barcellos*
Several studies conducted around the world over the last decade have demonstrated that early childhood and adolescent obesity are significant risk factors for MS susceptibility. This association has been largely confirmed in females, while evidence supporting a strong role for obesity and risk of MS in males has been mixed. Further, interaction between increased body mass index and genetic as well as environmental factors in MS susceptibility has been proposed, and evidence of a causal relationship has recently been established. In this review, we discuss findings supporting the significant association between obesity and MS, as well as identify areas for future investigation.DOI: 10.29245/2572.942X/2016/7.1064 View / Download Pdf
Biochemical and anatomical basis of brain dysfunctions caused by cytochrome b5 reductase deficiency or dysregulation
Alejandro K. Samhan-Arias1*, Carmen López-Sánchez2*, Dorinda Marques-da-Silva1, Ricardo Lagoa1,2,3Virginio Garcia-Lopez2,4, Virginio García-Martínez2Carlos Gutierrez-Merino1,#
Cytochrome b5 reductase (Cb5R) and cytochrome b5 (Cb5) are coupled redox systems with a high potential as biomarkers of health and disease in the brain because they regulate metabolic pathways that are essential to maintain normal neuronal function, like lipid biosynthesis, steroid and xenobiotics metabolism, neuronal bioenergetics and production of reactive oxygen species. Mutations of the Cb5R reported in humans produce recessive congenital methemoglobinemia of type II, a disease with severe clinical neurological dysfunctions. The isoform 3 of Cb5R (Cb5R3) and Cb5 are highly expressed in pyramidal neurons of the primary and secondary motor areas of frontoparietal cerebral cortex, hippocampus, vestibular, reticular and motor nuclei of the cerebellum and brain stem, and also in Purkinje and granule neurons of the cerebellum cortex. These brain areas are highly prone to undergo oxidative stress-induced neurodegeneration and their functional impairment can account for neurological deficits reported in type II congenital methemoglobinemia.DOI: 10.29245/2572.942X/2016/6.1066 View / Download Pdf
Primary age-related tauopathy and the amyloid cascade hypothesis: the exception that proves the rule?
John F. Crary
Extensive data supports the amyloid cascade hypothesis, which states that Alzheimer’s disease (AD) stems from neurotoxic forms of the amyloid-beta(Aβ)peptide. But the poor correlation between Aβ plaques and neurodegeneration/cognitive impairment, the spaciotemporal disparity between Aβ and tau pathology, and the disappointing results following several large clinical trials using Aβ-targeting agents are inconsistent with this explanation. The most perplexing inconsistency is the existence of AD-type dementia patients that develop abundant neurofibrillary tangles that are indistinguishable from those in early to moderate-stage AD in the absence of compelling evidence of amyloid toxicity. This neuropathological phenotype, which is distinct from other diseases with tangles, represents a conceptual disconnect, because it does not fall within any previously established category of tauopathy and ostensibly invalidates the amyloid cascade hypothesis. Instead, recent efforts have led to consensus criteria for a new alternative diagnostic category, which presupposes that these tangle-only dementia patients represent extreme examples of a distinct primary age-related tauopathy (PART) that is universally observed, albeit to varying degrees, in the aging brain. The cause of PART is unknown, but sufficient evidence exists to hypothesize that it stems from an Aβ-independent mechanism, such as mechanical injury. Should the PART hypothesis withstand further experimental testing, it would represent a shift in the way a subset of subjects with AD neuropathological change are classified and has the potential to focus and reaffirm the amyloid cascade hypothesis.DOI: 10.29245/2572.942X/2016/6.1059 View / Download Pdf
Clinical commentary: Systemic and subclinical adverse effects of repeated botulinum toxin a injections to decrease spasticity in adults affected by stroke undergoing rehabilitation
Maria Amelia Chang
This is a clinical commentary that expands on an initial attempt to classify possible adverse effects (AE) of repeated and long-term use of Botox A (BTX) to manage post-stroke spasticity into three types, local, systemic and subclinical AE. Clinical manifestations of non-local, systemic AE from widespread diffusion of BTX are presented to help clinicians and researchers recognize changes that may develop in post-stroke patients. Subclinical AE of muscle atrophy and bone degradation may hinder return of motor control and increase certain risk factors. Even with increased trend in the use of BTX, very little is written about long term effects of repeated BTX injections for post-stroke spasticity coupled by fewer clinicians who report what they find in actual practice. Although published studies infrequently report AE, it will be an error if it is attributed to an extension of the disease process in stroke.DOI: 10.29245/2572.942X/2016/6.1054 View / Download Pdf
Kimbra Kenney, Margalit Haber, Franck Amyot, Cora Davis, Angela Pronger, Carol Moore, Ramon Diaz-Arrastia*
Traumatic cerebral vascular injury (TCVI) is a frequent, perhaps universal, feature after traumatic brain injury (TBI) and may be responsible for some TBI-related chronic disability. Because there are multiple pharmacologic and non-pharmacologic therapies that promote vascular health, TCVI is an attractive target for therapeutic intervention after TBI. The cerebral microvasculature (CMV) is a component of the neurovascular unit (NVU) coupling neuronal metabolism with local cerebral blood flow. The NVU participates in the pathogenesis of TBI, either directly from physical trauma or as part of the cascade of secondary injury that occurs after TBI. Pathologically, there is extensive microvascular injury in humans and experimental animals, identified with either conventional light microscopy or ultrastructural examination. It is seen in acute and chronic TBI and even described in chronic traumatic encephalopathy (CTE). Non-invasive, physiologic measures of cerebral microvascular function show dysfunction after TBI in humans and experimental animal models of TBI. These include imaging sequences Arterial Spin Labeling (ASL), Transcranial Doppler, Near InfraRed Spectroscopy (NIRS), etc. Understanding the pathophysiology of TCVI, a relatively under-studied component of TBI, has promise for developing novel TBI therapies.DOI: 10.29245/2572.942X/2016/6.1067 View / Download Pdf
DOI: 10.29245/2572.942X/2016/6.1050 View / Download Pdf
Rohit Aiyer1*, Lynne Voutsinas2, Yasir El-Sherif3
Barbro H Skogman1*, Johanna Sjöwall2, Per-Eric Lindgren3
DOI: 10.29245/2572.942X/2016/6.1057 View / Download Pdf
Erna A. van Niekerk*
Spinal cord injury (SCI) research continues to make substantial progress in identifying both neuron-intrinsic and neuron-extrinsic mechanisms that limit central nervous system (CNS) plasticity and regeneration. The identification of these mechanisms has in turn led to several novel strategies for therapeutically enhancing recovery of the injured CNS. Despite this progress, clinical translation remains a challenge for several reasons, including: 1) problems in projecting beneficial outcomes from small animal models to primate systems, 2) a lack of robust improvement in functional outcomes in animal models, and 3) difficulty replicating published reports in the field. Collectively, while the field has seen great progress, reconstructing the exquisite circuitry of the injured human CNS will require yet greater progress in both understanding of basic mechanisms underlying axonal growth and guidance, and testing of optimized therapies in models more predictive of potential human benefit.DOI: 10.29245/2572.942X/2016/6.1056 View / Download Pdf
Enhancement of Local Retionic Acid Signaling: A Pivotal Mechanism in Fluoxetine's Pleiotropic Actions
Vera Clemens, Francesca Regen, Julian Hellmann-Regen*
Major depression (MDD) is one of the leading global causes of all non-fatal burden of disease. Involving monoaminergic imbalances, but also hormonal, structural and inflammatory alterations, the underlying pathogenesis remains incompletely understood. The antidepressant drug fluoxetine, which may be considered the “prototype” of all selective serotonin reuptake inhibitors (SSRI), appears to affect all of these processes. Interestingly, this is also the case for retinoic acid (RA), the highly potent active metabolite of vitamin A. In this review, we discuss RA signaling as a central mechanism of action – and missing link – for the multiple, pleiotropic effects of fluoxetine in the CNS, suggesting that direct inhibition of CYP-450-mediated RA catabolism by fluoxetine results in increased local concentration, and enhanced paracrine RA signaling in the CNS.DOI: 10.29245/2572.942X/2016/6.1028 View / Download Pdf