All Articles

Rohit Aiyer^1*, Lynne Voutsinas², Yasir El-Sherif³

Barbro H Skogman^1*, Johanna Sjöwall², Per-Eric Lindgren³

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.

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.

Gregory D. Arnone¹, Matt Wonais², Andreas Linninger^1,3, Ankit I. Mehta^1*

Deepika Rajesh, H. Ian Robins*, Steven P. Howard

The poor prognosis of malignant glioma patients highlights the need to develop low toxicity, tumor specific agents with the ability to synergize with proven efficacious treatment modalities, e.g., ionizing irradiation. This paper investigates the potential of BNP1350 (karenitecin), a topoisomerase I-targeting anticancer agent, and flavopridol a cyclin-dependent kinase inhibitor as radiosensitizers at clinically relevant doses in glioblastoma cell lines. A clonogenic survival and apoptosis assays were performed to test the effect of karenitecin (0.1 nM to 10 nM), flavopridol, (50 nM to 500 nM), radiation (1 Gy to 5.5 Gy) and a combination of radiation and karenitecin or radiation and flavopridol on the glioma cell lines T986 and M059K. Cells were stained for cyclins B and D using antibodies followed by flow cytometry. Propidium Iodide staining was used to reveal the various phases of the cell cycle; cyclin staining in the G0/G1 and G2/M phase of the cell cycle was estimated as the Mean Fluorescence Intensity (MFI) after subtracting the MFI recorded by the isotype controls. Results demonstrated that in irradiated cells, pretreatment with karenitecin induced apoptosis, a transient arrest in the G2/M phase of the cell cycle and increased the expression of cyclin B1. Flavopridol treatment also induced apoptosis and a transient block in the G2/M phase of the cell cycle. The combined effects of karenitecin and flavopridol displayed synergistic effects. The unique radiosensitizing activity of orally administrable karenitecin and flavopridol is consistent with continued investigation of these compounds preclinically, as well as in the clinical setting.

Yeu-Shiuan Su^1*, Wei-Hsin Sun^1,2*

Serotonin [5-hydroxytryptamine (5-HT)] is an inflammatory mediator which contributes to inflammatory pain. We previously demonstrated that 5-HT-induced mechanical hyperalgesia is mediated by 5-HT2B, but not by other 5-HT receptors. Our recent article provided further evidence how 5-HT2B regulates 5-HT-induced mechanical hyperalgesia, and suggested, that 5-HT2Bmediates mechanical hyperalgesia through Gq/11-phospholipase Cβ (PLCβ)-protein kinase Cε (PKCε) pathway. Interestingly, transient receptor potential vanilloid 1 (TRPV1) also involves in 5-HT2B-mediated hyperalgesia. It was the first evidence that 5-HT receptor regulates TRP channel to affect mechanical hyperalgesia. It is a commentary on the recent article that suggests distinct roles of peptidergic (IB4-negative) and non-peptidergic (IB4-positive) nociceptors in regulating 5-HT-induced mechanical hyperalgesia. In IB4-negative neurons, 5-HT2B in response to 5-HT mediates PLCβ-PKCε to regulate TRPV1 function. In IB4-positive neurons, 5-HT2B may control 5-HT3 or other channels to regulate mechanical hyperalgesia.

Lara A. Haeusser, Lothar Kanz, Marcus M. Schittenhelm, Kerstin M. Kampa-Schittenhelm^*

The endocannabinoid system is extensively studied in neuroscience and clinical use of cannabinoid derivatives as substances with remarkable spasmolytic effects in multiple sclerosis and antiemetic potential in cancer therapy as well as pain-relieving properties is broadly acknowledged.

However, it becomes increasingly apparent, that in addition cannabinoids exert manifold functions in various organ systems, such as the immune system, the reproductive or cardiovascular system among others. Moreover, interactions with signaling pathways involved in programmed cell death, angiogenesis, metastasis or anti-tumor immunity make it highly suggestive that cannabinoids may have therapeutic potential in the treatment of cancer. Indeed, detailed reports have repeatedly shown anticancer efficacy in solid and hematologic tumor models, best characterized in human gliomas.

Anecdotal evidence of blast control in a young patient with acute myeloid leukemia has led us to systematically investigate the potential use of cannabinoids in the treatment of acute leukemia.

Owing to the critical cellular role of lysosomes in the myelination, mounting studies focus on the mechanisms underlying exocytosis of lysosome in nervous system has emerged. In this paper, we briefly introduce the recent advances in this respect.

These data are summarized herein in the context of key data regarding anticancer efficacy of cannabinoids.

James Giordano^1,2*, Kira Becker^1,3, John R. Shook⁴

Neuroethics is a relatively new, yet ever expanding discipline, which focuses on the “neuroscience of ethics” and the “ethics of neuroscience”. In this essay, we discuss the literature describing the “neuroscience of ethics”. Current approaches to employing neuroscientific techniques and tools to elucidate brain processes serving ethical decision making has evolved from prior psychological studies of how and why humans believe and act in ways deemed to be moral. While a number of neuroanatomical pathways have been defined as participatory in certain types of decision-making, it appears that none are exclusively dedicated to moral cognition or actions. Moreover, attempts at enhancing morality through neurological interventions are plagued by differing constructs of what constitutes moral action in various contexts. Herein, we review developments in neuroscientific studies of morality, and present a rational view of the capabilities, limitations and responsibilities that any genuine neuroethical address and discourse should regard.

GJ de Borst*, V.E.C. Pourier

Eduardo NC Bergamaschi¹, Fernanda C Nunes^2,3, Victor W de Oliveira³, Alessandra Laitart³, Maria L Benevides³, Jean C Nunes^2,3*

 Pain is a common and often disabling symptom in Parkinson’s disease (PD) which has received increasing attention in recent years. Headache represents a common form of pain among the general population, but there are few studies on this symptom in PD. In 2014, our group reported a lower prevalence of headache in PD patients compared to the general population, as well as an association between the predominant side of headache and the side of initial motor signs of PD. Since then, there has been few new data on the specific issue of headache in PD patients, though several recent studies have contributed to the understanding of pain in PD, both in terms of clinical and pathophysiological aspects, including new observations on pain association with side of motor symptom onset. Here, we review those studies, and re-discuss our own findings in comparison to the current information available. A better comprehension of pain physiology in PD could facilitate the development of new therapeutic approaches, thus providing a better quality of life for PD patients.

Masashi Kanayama¹, Mari L. Shinohara^2*

 Abstract Autoimmune diseases of the central nervous system (CNS), such as multiple sclerosis (MS), are characterized by infiltration of pathogenic immune cells in the CNS. Cells infiltrated in the CNS express pro-inflammatory molecules and cause demyelination. The direct impact of lung immune responses was not previously considered in the pathogenesis of CNS inflammation. However, it recently became clear that the lung acts as a hub organ of pathogenic T cells that are migrating to the CNS. More recent studies further showed that inflamed lung has a critical impact on autoimmune CNS inflammation. Here, we discuss the contribution of the lung in the pathogenesis of CNS autoimmune diseases based on recent reports.

Yun-Tian Shen¹, Ying Yuan^1,2, Wen-Feng Su¹, Yun Gu¹, Gang Chen^1*

 The myelin sheath wraps axons is an intricate process required for rapid conduction of nerve impulses, which is formed by two kinds of glial cells, oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. Myelin biogenesis is a complex and finely regulated process and accumulating evidence suggests that myelin protein synthesis, storage and transportation are key elements of myelination, however the mechanisms of regulating myelin protein trafficking are still not very clear. Recently, the evidences of lysosomal exocytosis in oligodendrocytes and Schwann cells are involved in regulated myelination have emerged. In this paper, we briefly summarize how the major myelin-resident protein, as proteolipid protein in the central nervous system and P0 in the peripheral nervous system, transport from lysosome to cell surface to form myelin sheath and focus on the possible mechanisms involved in these processes. Advances in our understanding of glia, as well as new tools engineering, will further improve the knowing of myelin biogenesis.

Esther A. Pelzer^1,2*, Lars Timmermann², Marc Tittgemeyer¹

 Subcortical communication is an important underlying feature for the smooth performance of motor behaviour. Especially movement disorders like Parkinson’s disease show impairment in the basal-ganglio-thalamic and cerebello-thalamic communication; but also an impairment of the direct communication between these two structures has been proposed.

In this review we highlight important clinical findings concerning the pathological communication between these subcortical structures; additionally we propose a new hypothesis in the development of neurodegenerative disease: we assume that axon degeneration is crucially implicated in the development of parkinsonian symptoms and link the current findings to the development of pathological oscillatory activity. New techniques like probabilistic tractography now offer the possibility to in vivo measure axon degeneration by the determination of connectivity decline and allow the combination with electrophysiological recording. We hypothesize that a change in frequency bands in oscillatory activity might be a product of underlying axonal degeneration; moreover axonal degeneration might be worsened by pathological oscillatory activity resulting in a vicious circle. The thalamus, as main relay station between the basal ganglia and the cerebellum seems to be involved in this disease pathology in Parkinson’s disease.

Robert C.A.M. van Waardenburg*

 Tyrosyl-DNA phosphodiesterase I (TDP1), like most DNA repair associated proteins, is not essential for cell viability. However, dysfunctioning TDP1 or ATM (ataxia telangiectasia mutated) results in autosomal recessive neuropathology with similar phenotypes, including cerebellar atrophy. Dual inactivation of TDP1 and ATM causes synthetic lethality. A TDP1H493R catalytic mutant is associated with spinocerebellar ataxia with axonal neuropathy (SCAN1), and stabilizes the TDP1 catalytic obligatory enzyme-DNA covalent complex. The ATM kinase activates proteins early on in response to DNA damage. Tdp1-/- and Atm-/- mice exhibit accumulation of DNA topoisomerase I-DNA covalent complexes (TOPO1-cc) explicitly in neuronal tissue during development. TDP1 resolves 3’- and 5’-DNA adducts including trapped TOPO1-cc and TOPO1 protease resistant peptide-DNA complex. ATM appears to regulate the response to TOPO1-cc via a noncanonical function by regulating SUMO/ubiquitin-mediated TOPO1 degradation. In conclusion, TDP1 and ATM are critical factors for neuronal cell viability via two independent but cooperative pathways.

Becker L¹, Kutz DF², Voelcker-Rehage C^1*

Willemieke M. Kouwenhoven and Marten P. Smidt*

 Two essential monoaminergic neurotransmitter systems are located within the midbrain and the hindbrain region: the mesodiencephalic dopaminergic (mdDA) neurons, which can be divided in the substantia nigra (SN), the ventral tegmental area (VTA), and the serotonergic (5-HT) neurons. In the adult brain these two types of monoaminergic neurons are critical to our neurological health. Dysfunction of the mdDA system has been associated with schizophrenia and Parkinson's Disease (PD), while dysfunction of the 5HT system has in turn been associated with psychiatric diseases such as depression and autism. The homeobox transcription factor Engrailed 1 (En1) is expressed in both types monoaminergic neurons, and is required for the correct programming and survival of the mdDA and 5HT neurons. Recently, we reported on the dual role of En1 in both neurotransmitter systems through its central role in the maintenance of the Isthmic Organizer, which is the embryonic signaling center that instructs and separates dopaminergic and serotonergic neuronal development.

Ramón Martínez-Mármol¹, Mercè Salla-Martret², Daniel Sastre², Irene Estadella², Antonio Felipe^2*

 The adult mammalian brain contains neural stem cells (NSCs) that generate neurons and glial cells throughout the lifetime of an organism. NSCs reside in at least two germinal epithelium regions of the adult brain, the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone of the hippocampus. Newborn neurons incorporate into the existing functional networks and play important innate and adaptive roles in cognition, behavior and tissue repair1,2. The identity of particular neural stem cells that generate different classes of neurons and glia, as well as the molecular mechanisms that governs this process in vivo, is a subject of extensive research and debate. Epidermal Growth Factor Receptor (EGFR) activation is one of the most important pathways controlling neural stem cell number and self-renewal3,4. On the other hand, the Shaker-type delayed rectifier K+ channel Kv1.3 functions during cell proliferation, differentiation and migration in many cell types5. This channel is expressed in brain progenitor cells where participates in modulating their final fate. This review summarizes the major findings concerning Kv1.3 and neural stem cell modulation, emphasizing the combination of Kv1.3 with EGFR as promising pharmacological targets against autoimmune neuro-degenerative diseases.

Jonathan T. Blackmon¹, Toni Viator RN², Robert M. Conry^3*

Immune checkpoint inhibitors (CPIs) which unleash suppressed antitumor immune responses are revolutionizing the systemic treatment of cancer. Durable responses and prolongation of survival come at a price of frequent immune-related adverse events resulting from inflammation of normal tissues. Herein, we review serious central nervous system (CNS) toxicities of immune CPIs including ipilimumab, nivolumab, pembrolizumab and atezolizumab. Case reports of 20 patients with CPI-associated encephalitis, meningitis, or myelitis were reviewed as well as data from large scale registration trials. The overall incidence of serious immune-related CNS toxicities is approximately 0.4-1% with the potential for hundreds of cases annually in the United States. Patients suspected of having serious CPI-associated CNS toxicity should have a neurology consult, lumbar puncture, and MRI of the affected regions. If confirmed, the offending drug should be permanently discontinued and high dose intravenous steroids initiated, preferably with 500-1,000 mg of methylprednisolone daily. With timely diagnosis and appropriate management, the majority of patients experience complete neurologic recovery. As the array of indications for CPIs rapidly increases, it is imperative for clinicians to have a high index of suspicion for immune-related CNS toxicities.

Alma Rystedt¹, Kerstin Brismar², Sten-Magnus Aquilonius³, Hans Naver⁴, Carl Swartling^1,5*

¹Hidrosis Clinic, Stockholm, Sweden
²Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
³Department of Neuroscience, Neurology, Uppsala University, Uppsala University Hospital, Uppsala, Sweden
⁴Department of Internal Medicine, Neurology, Nyköping Hospital, Nyköping, Sweden
⁵Department of Medical Sciences, Dermatology and Venereology, Uppsala University, Uppsala, Sweden

Hyperhidrosis is a social, emotional and occupational disability which affects close to 3 % of the population. Patients with hyperhidrosis suffer an extremely negative impact on their quality of life on a par with being severely affected by psoriasis. Most of the sufferers have the primary genetic form of hyperhidrosis. Secondary hyperhidrosis can often be omitted based on anamnestic data, but sometimes further examinations must be performed.

Topical treatment (e.g. aluminium chloride) is the first choice for localised hyperhidrosis. Botulinum toxin, iontophoresis, microwave thermolysis (miraDry®), and/or systemic medications are indicated if topical treatment is insufficient or not applicable. Endoscopic Thoracic Sympathectomy (ETS) is no longer performed in Sweden due to the serious side effects profile. In countries where ETS still is performed, patients must be carefully selected and educated to fully understand the possibility of limited efficacy and the risks of complications including, but not limited to, compensatory sweating. This treatment should be the last option.

Examination- and treatment recommendations based on international guidelines and literature are presented in this review.

Cong-Cong Qi^1,2, Yu-Qiang Ding¹, Jiang-Ning Zhou^2*

The forced swim test (FST), originally developed by Porsolt et al., is highly valuable for assessing the antidepressant-like effects of the majority of currently-available antidepressants. Lucki et al. modified some parameters of the traditional FST in order to facilitate the differentiation between serotonergic and noradrenergic classes of antidepressant drugs. In addition, the FST is one of the most commonly used models for assessing antidepressant-like behaviors in both rats and mice. Focus on the present neuroscience field, knockout and transgenic mice provide a tool for assessing the mechanisms of action of antidepressants, and the factors influencing these behavior in the FST should be taken into considerations. In this MiniReview, we reviewed several biological factors (e.g. strain, gender, age, susceptibility) that may in?uence mice behavior in the FST and attempt to describe those variables that should be considered when designing studies employing the FST.

Rodger J. Elble

The Essential Tremor Rating Assessment Scale was developed by the Tremor Research Group (www.tremorresearchgroup.org) to quantify essential tremor severity and its impact on activities of daily living. This scale requires only a pen and paper, and can be completed in about 10 minutes. Upper extremity action tremor is the main focus of this scale, but action tremor is also assessed in the head, face, voice, and lower limbs. The scale has excellent face validity, inter- and intra-rater reliability, and sensitivity to change. The activities of daily living section correlates strongly with the performance section, and this scale also correlates strongly with transducer measures of tremor and with the Fahn-Tolosa-Marín tremor rating scale. In the Fahn-Tolosa-Marín tremor rating scale, upper extremity tremor greater than 4 cm corresponds to a maximum rating of 4, while grade 4 tremor in the Essential Tremor Rating Assessment Scale corresponds to an amplitude greater than 20 cm. Therefore, the Essential Tremor Rating Assessment Scale is better suited for assessment of severe essential tremor.

So Mi Lee^1,2, In-One Kim¹

Germ cell tumor (GCT) arising in the basal ganglia or thalami is relatively uncommon. It occurs most commonly in boys during second decade of life. It is difficult to diagnose early stage GCTs in these regions because the images are not so typical and the symptom onset is insidious. However, early diagnosis of this tumor is important because of the high radiosensitivity and potential curability. Early stage GCTs originating from the basal ganglia or thalami appear as ill-defined small patchy lesions. They frequently present as hyperintense lesions compared with deep gray matter on T2-weighted image without cyst, mass effect, or prominent enhancement. Microhemorrhages can be accompanied infrequently. These tumors are mostly associated with ipsilateral hemiatrophy at the time of presentation. During tumor progression, tiny cysts develop at a relatively early stage, and intratumoral cyst, hemorrhage, and ipsilateral hemiatrophy gradually tend to be more pronounced. Ultimately, these become overt large mass with remarkable heterogenous enhancement, containing multiple cysts of various sizes and hemorrhage. This review aims to describe the serial MR imaging findings of the GCTs arising from basal ganglia or thalami, focusing on the early finding.

Homajoun Maslehaty^1*, Arya Nabavi², Hubertus Maximilian Mehdorn²

Qing Lu, Stephen M. Black

The neuronal cell death associated with perinatal asphyxia, or hypoxic-ischemic (HI) brain injury, plays an important role in neonatal mortality and neurodevelopment retardation. The types of cell death associated with HI in the brain have been classified as being either apoptotic or necrotic. Here we describe the recent discoveries of multiple non-apoptotic cell death pathways: necroptosis; ferroptosis; and autosis (autophagy). These new cell death pathways expand our understanding of the mechanisms underlying the cell death associated with perinatal asphyxia. By targeting specific regulators of these pathways, new therapies may be developed that could protect the neonatal brain from the HI mediated injury.