scholarly journals Human CA1 and subiculum activity forecast stroke chronicity

Author(s):  
Diogo Santos-Pata ◽  
Belén Rubio Ballester ◽  
Riccardo Zucca ◽  
Carlos Alberto Stefano Filho ◽  
Sara Regina Almeida ◽  
...  

ABSTRACTFollowing a stroke, the brain undergoes a process of neuronal reorganization to compensate for structural damage and cope with functionality loss. Increases in stroke-induced neurogenesis rates in the dentate gyrus and neural migration from the hippocampus towards the affected site have been observed, suggesting that the hippocampus is involved in functionality gains and neural reorganization. Despite the observed hippocampal contributions to structural changes, the hippocampal physiology for stroke recovery has been poorly characterized. To this end, we measured resting-state whole-brain activity from non-hippocampal stroke survivors (n=13) during functional MRI scanning. Analysis of multiple hippocampal subregions revealed that the voxel activity of hippocampal readout sites (CA1 and subiculum) forecast the patient’s chronicity stage stronger than early regions of the hippocampal circuit. Furthermore, we observed hemispheric-specific contributions to chronicity forecasting, raising the hypothesis that left and right hippocampus are functionally dissociable during recovery. In addition, we suggest that in contrast with whole-brain analysis, the monitoring of segregated and specialized sub-networks after stroke potentially reveals detailed aspects of stroke recovery. Altogether, our results shed light on the contribution of the subcortical-cortical interplay for neural reorganization and highlight new avenues for stroke rehabilitation.

1883 ◽  
Vol 29 (126) ◽  
pp. 188-205
Author(s):  
D. G. Thomson

Mental Exaltation, Mania.—The question of the Prognosis in Mental Exaltation—Mania—in its various forms, is a far more debatable and uncertain matter than in melancholia. The symptoms in melancholia being of a negative character due to a lowering or suspension of brain activity, we do not look for all those diversities, endless varieties and aspects which we may find in mania, be it simple, acute, or chronic. Generally there is an increased vitality, a state of hyperæsthesia, an increase in the activity of the brain, generally of the whole brain, and we must believe that these states will not so easily end in complete resolution as the condition of merely depressed action, or rather no action, which obtains in melancholia—I mean in melancholia generally, and not those states of acute melancholia which are supposed to be closely allied to the state which in other brains and under other subjective circumstances would give rise to mania from a pathological point of view. If this increased activity does not rapidly terminate in resolution, one of two things must occur—either exhaustion or atrophy, resulting in death or dementia, will supervene, or abnormal tissue will invade or replace healthy nerve paths or areas, and chronic aberration of mind ensue.


2019 ◽  
pp. 106-113 ◽  
Author(s):  
Parth Chholak ◽  
Alexander N. Pisarchik ◽  
Semen A. Kurkin ◽  
Vladimir A. Maksimenko ◽  
Alexander E. Hramov

The knowledge of the mechanisms of motor imagery (MI) is very important for the development of braincomputer interfaces. Depending on neurophysiological cortical activity, MI can be divided into two categories: visual imagery (VI) and kinesthetic imagery (KI). Our magnetoencephalography (MEG) experiments with ten untrained subjects provided evidences that inhibitory control plays a dominant role in KI. We found that communication between inferior parietal cortex and frontal cortex is realised in the mu-frequency range. We also pinpointed three gamma frequencies to be used for motor command communication. The use of artificial intelligence allowed us to classify MI of left and right hands with maximal classification accuracy using the brain activity encoded in the identified gamma frequencies which were then proposed to be used for communication of specifics. Mu-activity was identified as the carrier of gamma-activity between these areas by means of phase-amplitude coupling similar to the modern day radio wave transmission.


2021 ◽  
Vol 24 (1) ◽  
pp. 224-241
Author(s):  
Rosina Caterina Filimon

Abstract A new scientific discipline, neuromusicology, connects the scientific research of music and that of the nervous system, in particular of the brain. It studies the effects of music on the brain; the present paper relates to this particular field. Initially, the right hemisphere was associated with the process of music reception and it was considered that the activation of the left hemisphere was the responsibility of language. Neuroimaging, however, demonstrates that the elements of musical language activate various brain areas in both hemispheres, simultaneously generating the perception of music and emotions. Research in the field of psychoacoustics has revealed that listening to music triggers the production of neurotransmitters in the body that relieve pain, reduce stress and anxiety. Another effect determined by listening and studying music is the structural changes that occur at brain level due to brain neuroplasticity. Pathological changes at brain level have consequences in perception and influence all human activities. Disease alters the artistic creativity of people suffering from various pathologies, biographies of many artists proving that neurological diseases influenced their artistic activity. Decoding the functioning of the brain in the presence of music and its effects on brain activity make it possible to use music therapy as a complementary method to medical treatment. The harmful effects of the current Covid-19 pandemic on the brain are obvious and are already reported in completed or ongoing research studies. The adoption of music as a therapeutic tool in the current global epidemiological crisis highlights its undeniable qualities in multiple pathologies and updates its mental and somatic benefits, complementary to medicine. All this provides an important drive in the reassessment and reconfiguration of the need to amplify the interference strategies between the field of music and that of medicine, implicitly that of neurology.


Author(s):  
Yu. G. Khomenko ◽  
G. V. Kataeva ◽  
V. I. Kolomiec

PET study of cerebral glucose metabolism was performed in 73 children with epilepsy and mental retardation. Expressive speech disorders were associated with decrease of cerebral metabolism rate of glucose (CMRglu) in the upper frontal gyrus, caudate nucleus and thalamus of the left and right hemispheres. In the group with combined expressive and impressive speech disorders the significant CMRglu reduction in the middle temporal and supramarginal gyrus of the left hemisphere was observed. The obtained results confirm that the brain structures associated with the executive functions and complex association processes have a great significance in the speech development.


2020 ◽  
Author(s):  
Carlos Coronel-Oliveros ◽  
Rodrigo Cofré ◽  
Patricio Orio

AbstractSegregation and integration are two fundamental principles of brain structural and functional organization. Neuroimaging studies have shown that the brain transits between different functionally segregated and integrated states, and neuromodulatory systems have been proposed as key to facilitate these transitions. Although computational models have reproduced the effect of neuromodulation at the whole-brain level, the role of local inhibitory circuits and their cholinergic modulation has not been studied. In this article, we consider a Jansen & Rit whole-brain model in a network interconnected using a human connectome, and study the influence of the cholinergic and noradrenergic neuromodulatory systems on the segregation/integration balance. In our model, a newly introduced local inhibitory feedback enables the integration of whole-brain activity, and its modulation interacts with the other neuromodulatory influences to facilitate the transit between different functional states. Moreover, the new proposed model is able to reproduce an inverted-U relationship between noradrenergic modulation and network integration. Our work proposes a new possible mechanism behind segregation and integration in the brain.


2017 ◽  
Vol 25 (3) ◽  
pp. 399-403
Author(s):  
V. V. Sychev ◽  
V. N. Sychev ◽  
N. V. Shatrova

According to some authors, changes in the electroencephalogram (EEG) in the absence of clinical paroxysmal manifestations should be considered as subclinical epileptic manifestations. Verification of this hypothesis on the basis of the auto-spectral Fourier analysis of the EEG was the purpose of this work. Were examined in 27 women, mean age of 35.4±2.48 years, right-handed, without paroxysmal clinical and EEG manifestations (first group) and 25 women, mean age of 36.2±2.17 years, right-handed, without paroxysmal clinical manifestations, but with epileptiform activity on EEG (second group). In the second group were registered the increase in faverage of the brain EEG (p<0.001), while was increased faverage both of the left and right hemisphere (p<0.01). Zonal peculiarities of bioelectric activity of a brain of the second group surveyed was a significant increase in faverage EEG in all investigated leads (p<0.01), resulting in total liquidation of zonal differences (p>0.05). The results of the analysis allowed to conclude that the registration of the EEG epileptiform paroxysmal phenomena without clinical manifestations should be considered as a subclinical stage of epilepsy.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Lv Han ◽  
Liu Zhaohui ◽  
Yan Fei ◽  
Li Ting ◽  
Zhao Pengfei ◽  
...  

Numerous investigations studying the brain functional activity of the tinnitus patients have indicated that neurological changes are important findings of this kind of disease. However, the pulsatile tinnitus (PT) patients were excluded in previous studies because of the totally different mechanisms of the two subtype tinnitus. The aim of this study is to investigate whether altered baseline brain activity presents in patients with PT using resting-state functional magnetic resonance imaging (rs-fMRI) technique. The present study used unilateral PT patients (n=42) and age-, sex-, and education-matched normal control subjects (n=42) to investigate the changes in structural and amplitude of low-frequency (ALFF) of the brain. Also, we analyzed the relationships between these changes with clinical data of the PT patients. Compared with normal controls, PT patients did not show any structural changes. PT patients showed significant increased ALFF in the bilateral precuneus, and bilateral inferior frontal gyrus (IFG) and decreased ALFF in multiple occipital areas. Moreover, the increased THI score and PT duration was correlated with increased ALFF in precuneus and bilateral IFG. The abnormalities of spontaneous brain activity reflected by ALFF measurements in the absence of structural changes may provide insights into the neural reorganization in PT patients.


2021 ◽  
Author(s):  
Jaakko Paasonen ◽  
Petteri Stenroos ◽  
Hanne Laakso ◽  
Tiina Pirttimaki ◽  
Ekaterina Paasonen ◽  
...  

Understanding the link between the brain activity and behavior is a key challenge in modern neuroscience. Behavioral neuroscience, however, lacks tools to record whole-brain activity in complex behavioral settings. Here we demonstrate that a novel Multi-Band SWeep Imaging with Fourier Transformation (MB-SWIFT) functional magnetic resonance imaging (fMRI) approach enables whole-brain studies in spontaneously behaving head-fixed rats. First, we show anatomically relevant functional parcellation. Second, we show sensory, motor, exploration, and stress-related brain activity in relevant networks during corresponding spontaneous behavior. Third, we show odor-induced activation of olfactory system with high correlation between the fMRI and behavioral responses. We conclude that the applied methodology enables novel behavioral study designs in rodents focusing on tasks, cognition, emotions, physical exercise, and social interaction. Importantly, novel zero echo time and large bandwidth approaches, such as MB-SWIFT, can be applied for human behavioral studies, allowing more freedom as body movement is dramatically less restricting factor.


2021 ◽  
Vol 17 (2) ◽  
pp. e1008737
Author(s):  
Carlos Coronel-Oliveros ◽  
Rodrigo Cofré ◽  
Patricio Orio

Segregation and integration are two fundamental principles of brain structural and functional organization. Neuroimaging studies have shown that the brain transits between different functionally segregated and integrated states, and neuromodulatory systems have been proposed as key to facilitate these transitions. Although whole-brain computational models have reproduced this neuromodulatory effect, the role of local inhibitory circuits and their cholinergic modulation has not been studied. In this article, we consider a Jansen & Rit whole-brain model in a network interconnected using a human connectome, and study the influence of the cholinergic and noradrenergic neuromodulatory systems on the segregation/integration balance. In our model, we introduce a local inhibitory feedback as a plausible biophysical mechanism that enables the integration of whole-brain activity, and that interacts with the other neuromodulatory influences to facilitate the transition between different functional segregation/integration regimes in the brain.


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