Tinnitus Neural Mechanisms and Structural Changes in the Brain: The Contribution of Neuroimaging Research

Affective disorders, such as anxiety and depression, are common comorbidities associated with chronic insomnia disorder (CID). However, the underlying neural mechanisms of these comorbidities are still not clear. The present study is aimed at investigating structural changes in the amygdala of CID patients using surface-based shape analysis. A total of 65 medication-naive patients with CID and 55 healthy controls (HCs) matched for age, sex, and years of education were enrolled in this study and were subjected to structural magnetic resonance imaging (MRI). The Oxford Centre for Functional MRI of the Brain (FMRIB) created an Integrated Registration and Segmentation Tool (FIRST) that was employed in this study to assess the volumetric and surface alterations in patients with CID. Shape correlations between the amygdala and clinical features were also analyzed. Atrophic changes in the amygdala were observed at the local level, not for the entire amygdala volume. The left atrophic changes in the amygdala were in the superficial and basolateral nuclei while right atrophic changes were in the basolateral nuclei in CID patients. Insomnia severity was associated with the centromedial right amygdala while anxiety was linked with the basolateral nuclei. These findings indicate localized amygdala atrophy in CID. Separate amygdala regions are associated with insomnia and anxiety in CID. This evidence helps elucidate the neural mechanisms underlying the bidirectional relationship between insomnia and anxiety.

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Neural Mechanisms and Children’s Intellectual Development

The Neuroscientist ◽

10.1177/1073858415610294 ◽

2016 ◽

Vol 22 (6) ◽

pp. 618-631 ◽

Cited By ~ 6

Author(s):

Hikaru Takeuchi ◽

Ryuta Kawashima

Keyword(s):

Environmental Factors ◽

Intellectual Development ◽

Structural Changes ◽

Brain Volume ◽

Neural Mechanisms ◽

The Third ◽

Human Brain Development ◽

Human Brains ◽

The Brain ◽

Later Phase

Human psychometric intelligence can predict a number of important social and academic outcomes. Substantial parts of the variances of human intelligence and the brain volume supporting those abilities are explained by environmental factors, and during childhood, human brains have higher plasticity and also 60% of variance of intelligence that is explained by environmental factors. Here, we review the representative environmental factors known to affect human intellectual development during each developmental stage. We describe what is (and what is not) being investigated to determine how these factors affect human brain development through analyses of volumetrical and cortical structures. In conclusion, environmental factors that affect children’s intellectual development lead to three patterns of brain structural change. The first is global change in the brain structure, observed more often in the earlier phase of development. The second is structural changes concentrated in the medial prefrontal and adjacent areas and medial temporal areas, which are likely to be induced by stress in many cases. The third is sporadic region-specific change, likely to be primarily caused by use-dependent plasticity of the areas that is often observed in the later phase of development. These changes may underlie the alterations in children’s intellectual development that is induced by environmental factors.

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Neuroanatomical voxel-based profile of schizophrenia and bipolar disorder

Epidemiology and Psychiatric Sciences ◽

10.1017/s2045796016000275 ◽

2016 ◽

Vol 25 (4) ◽

pp. 312-316 ◽

Cited By ~ 21

Author(s):

E. Maggioni ◽

M. Bellani ◽

A. C. Altamura ◽

P. Brambilla

Keyword(s):

Bipolar Disorder ◽

Grey Matter ◽

Structural Changes ◽

Temporal Cortex ◽

Treatment Strategies ◽

Neural Mechanisms ◽

Anterior Cingulate ◽

Healthy Controls ◽

Structural Differences ◽

The Brain

Although schizophrenia (SCZ) and bipolar disorder (BD) share elements of pathology (Ellison-Wright and Bullmore, 2009), the neural mechanisms underlying these disorders are still under investigation. Up until now, many neuroimaging studies investigated the brain structural differences of SCZ and BD compared with healthy controls (HC), trying to identify the possible neuroanatomical markers for the two disorders. However, just a few studies focused on the brain structural changes between the two diagnoses. The present review summarises the findings of the voxel-based grey matter (GM) comparisons between SCZ and BD, with the objective to highlight the possible consistent anatomical differences between the two disorders. While the comparisons between patients and HC highlighted overlapping areas of GM reduction in insula and anterior cingulate cortex, the SCZ–BD comparisons suggest the presence of more generalised GM deficits in SCZ compared with BD. Indeed, in a number of studies, SCZ patients showed lower GM volumes than BD patients in fronto-temporal cortex, thalamus, hippocampus and amygdala. Conversely, only a couple of studies reported GM deficits in BD compared with SCZ, both at the level of cerebellum. In summary, the two disorders exhibit both common and specific neuroanatomical characteristics, whose knowledge is mandatory to develop innovative diagnostic and treatment strategies.

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Native Ubiquitin Structural Changes Resulting from Complexation with β-methylamino-L-alanine (BMAA)

10.26434/chemrxiv.12996335.v1 ◽

2020 ◽

Author(s):

Katie Mae Wilson ◽

Aurora Burkus-Matesevac ◽

Samuel Maddox ◽

Christopher Chouinard

Keyword(s):

Structural Changes ◽

Noncovalent Complex ◽

Unfolded Protein ◽

Protein Size ◽

High Concentrations ◽

The Unfolded Protein Response ◽

Critical Binding ◽

Protein Response ◽

The Brain ◽

Lateral Sclerosis

β-methylamino-L-alanine (BMAA) has been linked to the development of neurodegenerative (ND) symptoms following chronic environmental exposure through water and dietary sources. The brains of those affected by this condition, often referred to as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), have exhibited the presence of plaques and neurofibrillary tangles (NFTs) from protein aggregation. Although numerous studies have sought to better understand the correlation between BMAA exposure and onset of ND symptoms, no definitive link has been identified. One prevailing hypothesis is that BMAA acts a small molecule ligand, complexing with critical proteins in the brain and reducing their function. The objective of this research was to investigate the effects of BMAA exposure on the native structure of ubiquitin. We hypothesized that formation of a Ubiquitin+BMAA noncovalent complex would alter the protein’s structure and folding and ultimately affect the ubiquitinproteasome system (UPS) and the unfolded protein response (UPR). Ion mobility-mass spectrometry revealed that at sufficiently high concentrations BMAA did in fact form a noncovalent complex with ubiquitin, however similar complexes were identified for a range of additional amino acids. Collision induced unfolding (CIU) was used to interrogate the unfolding dynamics of native ubiquitin and these Ubq-amino acid complexes and it was determined that complexation with BMAA led to a significant alteration in native protein size and conformation, and this complex required considerably more energy to unfold. This indicates that the complex remains more stable under native conditions and this may indicate that BMAA has attached to a critical binding location.

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Native Ubiquitin Structural Changes Resulting from Complexation with β-methylamino-L-alanine (BMAA)

10.26434/chemrxiv.12996335 ◽

2020 ◽

Author(s):

Katie Mae Wilson ◽

Aurora Burkus-Matesevac ◽

Samuel Maddox ◽

Christopher Chouinard

Keyword(s):

Structural Changes ◽

Noncovalent Complex ◽

Unfolded Protein ◽

Protein Size ◽

High Concentrations ◽

The Unfolded Protein Response ◽

Critical Binding ◽

Protein Response ◽

The Brain ◽

Lateral Sclerosis

β-methylamino-L-alanine (BMAA) has been linked to the development of neurodegenerative (ND) symptoms following chronic environmental exposure through water and dietary sources. The brains of those affected by this condition, often referred to as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), have exhibited the presence of plaques and neurofibrillary tangles (NFTs) from protein aggregation. Although numerous studies have sought to better understand the correlation between BMAA exposure and onset of ND symptoms, no definitive link has been identified. One prevailing hypothesis is that BMAA acts a small molecule ligand, complexing with critical proteins in the brain and reducing their function. The objective of this research was to investigate the effects of BMAA exposure on the native structure of ubiquitin. We hypothesized that formation of a Ubiquitin+BMAA noncovalent complex would alter the protein’s structure and folding and ultimately affect the ubiquitinproteasome system (UPS) and the unfolded protein response (UPR). Ion mobility-mass spectrometry revealed that at sufficiently high concentrations BMAA did in fact form a noncovalent complex with ubiquitin, however similar complexes were identified for a range of additional amino acids. Collision induced unfolding (CIU) was used to interrogate the unfolding dynamics of native ubiquitin and these Ubq-amino acid complexes and it was determined that complexation with BMAA led to a significant alteration in native protein size and conformation, and this complex required considerably more energy to unfold. This indicates that the complex remains more stable under native conditions and this may indicate that BMAA has attached to a critical binding location.

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Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

Scientific Reports ◽

10.1038/s41598-021-89843-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Florian Bitsch ◽

Philipp Berger ◽

Andreas Fink ◽

Arne Nagels ◽

Benjamin Straube ◽

...

Keyword(s):

Cognitive Control ◽

Positive Emotions ◽

Emotional Memory ◽

Brain Regions ◽

Neural Mechanisms ◽

Functional Magnetic Resonance ◽

Frontal Brain ◽

Successful Resolution ◽

Neural Underpinnings ◽

The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

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The association between biomarkers in cerebrospinal fluid and structural changes in the brain in patients with Alzheimer's disease

Journal of Internal Medicine ◽

10.1111/joim.12164 ◽

2013 ◽

Vol 275 (4) ◽

pp. 418-427 ◽

Cited By ~ 31

Author(s):

X. Li ◽

T.-Q. Li ◽

N. Andreasen ◽

M. K. Wiberg ◽

E. Westman ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cerebrospinal Fluid ◽

Structural Changes ◽

The Brain

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Ultrastructural changes of Basolateral Amygdaloid nuclei in the Sprague Dawley rats brain following exposure to naphthalene balls

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v12i2.4676 ◽

2021 ◽

Vol 12 (2) ◽

pp. 1272-1275

Author(s):

Angu Bala Ganesh K S V ◽

Sujeet Shekhar Sinha ◽

Kesavi Durairaj ◽

Abdul Sahabudeen K

Keyword(s):

Structural Changes ◽

Corn Oil ◽

Chromatin Condensation ◽

Ultrastructural Changes ◽

High Dose ◽

Model Group ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

The Brain ◽

Amygdaloid Nuclei

Naphthalene is a bicyclic aromatic constituent commonly used in different domestic and marketable applications comprising soil fumigants, lavatory scent disks and mothballs. Accidentally, workers, children and animals are exposed to naphthalene mothballs, so there is a need to study the pathology behind this chemical toxicity. The current study was carried out to assess the ultra structural changes of basolateral amygdaloid nuclei in the Sprague Dawley rats brain in association to naphthalene toxicity. The toxicity model group was administered with naphthalene (200 and 400mg) using corn oil as a vehicle for 28 days. The post delayed toxicity of naphthalene high dose ingestion was also assessed in rats. After the experimental period, the brain tissue was processed to observe the ultra structural changes using a transmission electron microscope. The alterations in cell organelles, nuclei damage, mitochondrial swelling, chromatin condensation suggested naphthalene induced damage in the neurons of the basolateral amygdala of the brain in the toxicity model group. These experimental trials provide information about the alert of mothball usage in the home and identify risks linked with accidental exposure and misuse.

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Neural Mechanisms of Negative Symptoms

The British Journal of Psychiatry ◽

10.1192/s0007125000291599 ◽

1989 ◽

Vol 155 (S7) ◽

pp. 93-98 ◽

Cited By ~ 40

Author(s):

Nancy C. Andreasen

Keyword(s):

Frontal Cortex ◽

Negative Symptoms ◽

Neural Mechanism ◽

Brain Regions ◽

Brain Dysfunction ◽

Neural Mechanisms ◽

Dementia Praecox ◽

Intellectual Abilities ◽

The Brain ◽

Psychic Mechanisms

When Kraepelin originally defined and described dementia praecox, he assumed that it was due to some type of neural mechanism. He hypothesised that abnormalities could occur in a variety of brain regions, including the prefrontal, auditory, and language regions of the cortex. Many members of his department, including Alzheimer and Nissl, were actively involved in the search for the neuropathological lesions that would characterise schizophrenia. Although Kraepelin did not use the term ‘negative symptoms', he describes them comprehensively and states explicitly that he believes the symptoms of schizophrenia can be explained in terms of brain dysfunction:“If it should be confirmed that the disease attacks by preference the frontal areas of the brain, the central convolutions and central lobes, this distribution would in a certain measure agree with our present views about the site of the psychic mechanisms which are principally injured by the disease. On various grounds, it is easy to believe that the frontal cortex, which is specially well developed in man, stands in closer relation to his higher intellectual abilities, and these are the faculties which in our patients invariably suffer profound loss in contrast to memory and acquired ability.” Kraepelin (1919, p. 219)

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Representation of Grammatical Categories of Words in the Brain

Journal of Cognitive Neuroscience ◽

10.1162/jocn.1995.7.3.396 ◽

1995 ◽

Vol 7 (3) ◽

pp. 396-407 ◽

Cited By ~ 129

Author(s):

Argye E. Hillis ◽

Alfonso Caramazza

Keyword(s):

Neural Mechanisms ◽

Single Patient ◽

Grammatical Category ◽

Lexical Knowledge ◽

Double Dissociation ◽

Category Information ◽

Orthographic Representations ◽

Organizational Principle ◽

The Brain ◽

Verbal Output

We report the performance of a patient who, as a consequence of left frontal and temporoparietal strokes, makes far more errors on nouns than on verbs in spoken output tasks, but makes far more errors on verbs than on nouns in written input tasks. This double dissociation within a single patient with respect to grammatical category provides evidence for the hypothesis that phonological and orthographic representations of nouns and verbs are processed by independent neural mechanisms. Furthermore, the opposite dissociation in the verbal output modality, an advantage for nouns over verbs in spoken tasks, by a different patient using the same stimuli has also been reported (Caramazza & Hillis, 1991). This double dissociation across patients on the same task indicates that results cannot be ascribed to "greater difficulty" with one type of stimulus, and provides further evidence for the view that grammatical category information is an important organizational principle of lexical knowledge in the brain.

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