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Topic Review
α-Synuclein
The α-syn, encoded by the SNCA1/PARK1 gene, is a ubiquitous protein that is abundantly expressed in kidneys and blood cells, but highly enriched in the brain, particularly in the presynaptic terminals of the neocortex, hippocampus, substantia nigra (SN), thalamus, and cerebellum. Interestingly, it has been found expressed in the cytoplasm of astrocytes and oligodendrocytes in healthy individuals.
  • 1.6K
  • 12 Nov 2021
Topic Review
The Microbial Hypothesis of Alzheimer’s Disease
The potential contribution of pathogenic microbes to dementia-inducing disease is a subject of considerable importance. Alzheimer’s disease (AD) is a neurocognitive disease that slowly destroys brain function, leading to cognitive decline and behavioral and psychiatric disorders. The histopathology of AD is associated with neuronal loss and progressive synaptic dysfunction, accompanied by the deposition of amyloid-β (Aβ) peptide in the form of parenchymal plaques and abnormal aggregated tau protein in the form of neurofibrillary tangles. The AD pathogen hypothesis states that pathogens and microbes act as triggers, interacting with genetic factors to initiate the accumulation of Aβ, hyperphosphorylated tau protein (p-tau), and inflammation in the brain. Evidence indicates that Borrelia sp., HSV-1, VZV (HHV-2), HHV-6/7, oral pathogens, Chlamydophila pneumoniae, and Candida albicans can infect the central nervous system (CNS), evade the immune system, and consequently prevail in the AD brain.
  • 1.6K
  • 06 Jun 2022
Topic Review
Mechanical Properties of Implant in Lumbar Interbody Fusion
Over the last decade, pedicle fixation systems have evolved and modifications in spinal fusion techniques have been developed to increase fusion rates and improve clinical outcomes after lumbar interbody fusion (LIF). Regarding materials used for screw and rod manufacturing, metals, especially titanium alloys, are the most popular resources. In the case of pedicle screws, that biomaterial can be also doped with hydroxyapatite, CaP, ECM, or tantalum. Other materials used for rod fabrication include cobalt–chromium alloys and nitinol (nickel–titanium alloy). In terms of mechanical properties, the ideal implant used in LIF should have high tensile and fatigue strength, Young’s modulus similar to that of the bone, and should be 100% resistant to corrosion to avoid mechanical failures.
  • 1.6K
  • 08 Jun 2022
Topic Review
Cell Autonomous Mechanisms in Astrocytes in Neurodegenerative Diseases
Neurodegenerative disorders like Alzheimer’s disease (AD), Parkinson’s disease (PD), frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) affect millions of people worldwide, and as the average human lifespan increases, similarly grows the number of patients. Cognitive and motoric decline has been explained by the very apparent deterioration of neurons in various regions of the brain and spinal cord. However, more studies show that disease progression is greatly influenced by the vast population of glial cells. Astrocytes are traditionally considered star-shaped cells on which neurons rely heavily for their optimal homeostasis and survival. Increasing amounts of evidence depict how astrocytes lose their supportive functions while simultaneously gaining toxic properties during neurodegeneration. 
  • 1.6K
  • 12 Mar 2024
Topic Review
Visual Hallucinations in Migraine and Epilepsy
Since the earliest descriptions of the simple visual hallucinations in migraine patients and in subjects suffering from occipital lobe epilepsy, several important issues have arisen in recognizing epileptic seizures of the occipital lobe, which often present with symptoms mimicking migraine. A detailed quantitative and qualitative clinical scrutiny of timing and characteristics of visual impairment can contribute to avoiding mistakes. Differential diagnosis, in children, might be challenging because of the partial clinical, therapeutic, and pathophysiological overlaps between the two diseases that often coexist. Ictal elementary visual hallucinations are defined by color, shape, size, location, movement, speed of appearance and duration, frequency, and associated symptoms and their progression. The evaluation of the distinctive clinical features of visual aura in migraine and visual hallucinations in occipital epilepsy could contribute to understanding the pathogenetic mechanisms of these two conditions. 
  • 1.6K
  • 04 May 2023
Topic Review
Modelling Parkinson’s Disease
Parkinson’s Disease (PD) is a chronic neurodegenerative disorder characterized by motor and non-motor symptoms, among which are bradykinesia, rigidity, tremor as well as mental symptoms such as dementia. 
  • 1.6K
  • 07 Jul 2021
Topic Review
The Effects of Diets on the “Gut–Brain” Pathways
With depression becoming increasingly prevalent, being closely associated with stress, and many patients exhibiting resistance to current treatments, depression pathophysiology requires further elucidation. Recent research has shown complex bidirectional links between the brain and the gut, and the gut microbiota and the influence of diet is beginning to provide new clues to the complex nature of this disorder. It is well known that diet is a key modulator of gut microbial composition. In humans, good quality plant-based diets such as the Mediterranean diet have been shown to reduce pathogenic bacteria in the gut, increase Bifidobacterium and Clostridium, as well as lower the risk of depression, while poorer quality diets such as the Western diet have been shown to reduce Lactobacillus in the gut, reduce overall gut microbial diversity and have been associated with increased depression risk. Evaluating the effects of diets on the brain-to-gut and gut-to-brain mechanisms in animal models of stress and depression may aid in the elucidation of the pathophysiology of depression and may provide novel therapeutic approaches. 
  • 1.5K
  • 21 Feb 2022
Topic Review
Neuromelanin in Parkinson’s Disease: Tyrosine Hydroxylase and Tyrosinase
Parkinson’s disease (PD) is an aging-related disease and the second most common neurodegenerative disease after Alzheimer’s disease. The main symptoms of PD are movement disorders accompanied with deficiency of neurotransmitter dopamine (DA) in the striatum due to cell death of the nigrostriatal DA neurons. Two main histopathological hallmarks exist in PD: cytosolic inclusion bodies termed Lewy bodies that mainly consist of α-synuclein protein, the oligomers of which produced by misfolding are regarded to be neurotoxic, causing DA cell death; and black pigments termed neuromelanin (NM) that are contained in DA neurons and markedly decrease in PD.
  • 1.5K
  • 15 Apr 2022
Topic Review
Neurofibromatosis and Schwannomatosis
Neurofibromatosis (NF) is a neurocutaneous syndrome characterized by the development of tumors of the central or peripheral nervous system including the brain, spinal cord, organs, skin, and bones. There are three types of NF: NF1 accounting for 96% of all cases, NF2 in 3%, and schwannomatosis (SWN) in <1%. The NF1 gene is located on chromosome 17q11.2, which encodes for a tumor suppressor protein, neurofibromin, that functions as a negative regulator of Ras/MAPK and PI3K/mTOR signaling pathways. The NF2 gene is identified on chromosome 22q12, which encodes for merlin, a tumor suppressor protein related to ezrin-radixin-moesin that modulates the activity of PI3K/AKT, Raf/MEK/ERK, and mTOR signaling pathways. In contrast, molecular insights on the different forms of SWN remain unclear. Inactivating mutations in the tumor suppressor genes SMARCB1 and LZTR1 are considered responsible for a majority of cases.
  • 1.5K
  • 08 Jun 2021
Topic Review
Fenamates for Neurodegenerative Disorders
Neurodegenerative disorders are desperately lacking treatment options. It is imperative that drug repurposing be considered in the fight against neurodegenerative diseases. Fenamates have been studied for efficacy in treating several neurodegenerative diseases. 
  • 1.5K
  • 06 May 2021
Topic Review
Callous and Unemotional (CU) Traits
Behavioral disorders (BD), including disruptive, aggressive, and/or antisocial behavior, are some of the most common disorders in children and adolescents. The notion of BD used in our review is an umbrella term, including children and adolescents with a range of emotional and behavioral disorders. It includes a population with heterogeneous behavioral diagnoses such as oppositional defiant disorder (ODD), conduct disorder (CD), internalized disorders (ID), conditions often associated with aggressive and/or antisocial behavior. Retrospective research in the field notes heterogeneous developmental trajectories that could be explained by certain risk factors, including the severity of callous-unemotional (CU) traits, a constellation of emotional and personality traits in children considered as a precursor to adult psychopathy.
  • 1.5K
  • 18 May 2021
Topic Review
Tryptophan Dysmetabolism and Quinolinic Acid in Neurodegenerative Diseases
Evidence suggests that neuroinflammation is involved in both depression and neurodegenerative diseases. The kynurenine pathway, generating metabolites which may play a role in pathogenesis, is one of several competing pathways of tryptophan metabolism. A disturbed tryptophan metabolism with increased activity of the kynurenine pathway and production of quinolinic acid may result in deficiencies in tryptophan and derived neurotransmitters. Quinolinic acid is an N-methyl-D-aspartate receptor agonist, and raised levels in CSF, together with increased levels of inflammatory cytokines, have been reported in mood disorders. Increased quinolinic acid has also been observed in neurodegenerative diseases, including Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, and HIV-related cognitive decline. 
  • 1.5K
  • 29 Jul 2022
Topic Review
Picein
Picein is a herbal agent that has been investigated in only a few studies. Picein is the active ingredient of several herbs and can thus be extracted from different types of plants, which renders it widely available. To date, picein has shown to exhibit antioxidant and anti-inflammatory properties in cellular and plant studies.
  • 1.5K
  • 31 Oct 2022
Topic Review
Mechanisms of Pain Modulation
A review of the pathophysiology of pain and its treatment, from a surgical point of view has been published (Sola RG, Pulido P. Neurosurgical Traatment of Pain. Brain Sci. 2022, 12(11), 1584; https://doi.org/10.3390/brainsci12111584) There are pain syndromes of difficult medical control.In these cases, surgical treatment may be an excellent alternative. The bases on which the different surgical approaches are based are described. The attached table shows a very schematic view of the neurosurgical treatment of pain.      
  • 1.5K
  • 22 Jan 2023
Topic Review
Antimyostatin Treatment
Myostatin, also known as growth and differentiation factor 8 (GDF-8), was identified in 1997 by McPherron and Lee.
  • 1.5K
  • 09 Jun 2021
Topic Review
Salt Intake
Salt (NaCl) intake is processed by receptors in the tongue and digestive system, which transmit the information to the nucleus of the solitary tract via a neural pathway (chorda tympani/vagus nerves) and to circumventricular organs, including the subfornical organ and area postrema, via a humoral pathway (blood/cerebrospinal fluid). Circuits are formed that stimulate or inhibit homeostatic sodium (Na) intake involving participation of the parabrachial nucleus, pre-locus coeruleus, medial tuberomammillary nuclei, median eminence, paraventricular and supraoptic nuclei, and other structures with reward properties such as the bed nucleus of the stria terminalis, central amygdala, and ventral tegmental area. Finally, the kidney uses neural signals (e.g., renal sympathetic nerves) and vascular (e.g., renal perfusion pressure) and humoral (e.g., renin–angiotensin–aldosterone system, cardiac natriuretic peptides, antidiuretic hormone, and oxytocin) factors to promote Na excretion or retention and thereby maintain extracellular fluid volume. 
  • 1.5K
  • 15 Feb 2023
Topic Review
Psychophysiological perspectives on emotion regulation
Several studies have suggested a correlation between heart rate variability (HRV), emotion regulation (ER), and consequent psychopathological conditions. Specifically, recent data seem to support the hypothesis that low-frequency heart rate variability (LF-HRV), an index of sympathetic cardiac control, correlates with worse ER and specific psychopathological dimensions. The present work aims to review the previous findings on these topics and integrate them from two main cornerstones of this perspective: Porges’ Polyvagal Theory and Thayer and Lane’s Neurovisceral Integration Model, which are necessary to understand these associations better. For this reason, based on these two approaches, we point out that low HRV is associated with emotional dysregulation and transversal psychopathological conditions. This understanding is beneficial as a theoretical ground from which to start for further research studies and as a starting point for new theoretical perspectives useful in clinical practice. 
  • 1.5K
  • 22 Sep 2021
Topic Review
Uncoupling Proteins for Neurodegenerative Diseases
Most of the major retinal degenerative diseases are associated with significant levels of oxidative stress. One of the major sources contributing to the overall level of stress is the reactive oxygen species (ROS) generated by mitochondria. The driving force for ROS production is the proton gradient across the inner mitochondrial membrane. This gradient can be modulated by members of the uncoupling protein family, particularly the widely expressed UCP2. The overexpression and knockout studies of UCP2 in mice have established the ability of this protein to provide neuroprotection in a number of animal models of neurological disease, including retinal diseases. The expression and activity of UCP2 are controlled at the transcriptional, translational and post-translational levels, making it an ideal candidate for therapeutic intervention. 
  • 1.5K
  • 30 Jun 2022
Topic Review
Xenopus Oocytes to Study Fully-Processed Membrane Proteins
The use of Xenopus oocytes in electrophysiological and biophysical research constitutes a long and successful story, providing major advances to the knowledge of the function and modulation of membrane proteins, mostly receptors, ion channels, and transporters. These cells are capable of correctly expressing heterologous proteins after injecting the corresponding mRNA or cDNA. The Xenopus oocyte has become an outstanding host–cell model to carry out detailed studies on the function of fully-processed foreign membrane proteins after their microtransplantation to the oocyte. 
  • 1.5K
  • 24 Oct 2022
Topic Review
Microglia and Macrophages as Emerging Therapies for Stroke
The mechanisms underlying the involvement of microglia and macrophages in both neuroprotection and neurogenesis after stroke are widely acknowledged as having a role in ischemic stroke pathology Since microglia and macrophages are regarded as major players in the pathological progression of ischemic stroke, modulating inflammation and neurological recovery is a hopeful strategy for treating the long-term outcomes after ischemic injury. 
  • 1.5K
  • 28 Mar 2022
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