scholarly journals Global dissociation of the amygdala from the rest of the brain during REM sleep

Author(s):  
Marta Matei ◽  
Antoine Bergel ◽  
Sophie Pezet ◽  
Mickael Tanter

Abstract Rapid-eye-movement sleep (REMS) or paradoxical sleep is associated with intense neuronal activity, fluctuations in autonomic control, body paralysis and brain-wide hyperemia. The mechanisms and functions of these energy-demanding patterns remain elusive and a global picture of brain activation during REMS is currently missing. In the present work, we performed functional ultrasound (fUS) imaging at the whole-brain scale during hundreds of REMS episodes to provide the spatiotemporal dynamics of vascular activity in 259 brain regions spanning more than 2/3 of the total brain volume. We first demonstrate a dissociation between basal/midbrain and cortical structures, the first ones sustaining tonic activation during REMS while the others are activated in phasic bouts. Second, we isolated the vascular compartment in our recordings and identified arteries in the anterior part of the brain as strongly involved in the blood supply during REMS episodes. Finally, we report a peculiar activation pattern in the amygdala, which is strikingly disconnected from the rest of the brain during most but not all REMS episodes. This last finding shows that amygdala undergoes specific processing during REMS and may be linked to the regulation of emotions and the creation of dream content during this very state.

2021 ◽  
Author(s):  
Marta Matei ◽  
Antoine Bergel ◽  
Sophie Pezet ◽  
Mickael Tanter

Abstract Rapid-eye-movement sleep (REMS) or paradoxical sleep is associated with intense neuronal activity, fluctuations in autonomic control, body paralysis and brain-wide hyperemia. The mechanisms and functions of these energy-demanding patterns remain elusive and a global picture of brain activation during REMS is currently missing. In the present work, we performed functional ultrasound (fUS) imaging at the whole-brain scale during hundreds of REMS episodes to provide the spatiotemporal dynamics of vascular activity in 259 brain regions spanning more than 2/3 of the total brain volume. We first demonstrate a dissociation between basal/midbrain and cortical structures, the first ones sustaining tonic activation during REMS while the others are activated in phasic bouts. Second, we isolated the vascular compartment in our recordings and identified arteries in the anterior part of the brain as strongly involved in the blood supply during REMS episodes. Finally, we report a peculiar activation pattern in the amygdala, which is strikingly disconnected from the rest of the brain during most but not all REMS episodes. This last finding shows that amygdala undergoes specific processing during REMS and may be linked to the regulation of emotions and the creation of dream content during this very state.


Author(s):  
Ian J. Deary

‘What do more intelligent brains look like?’ considers a study that used data from the Lothian Birth Cohort 1936 to test the strength of the correlation between the general intelligence scores of the participants and different measures of their brain’s structure. Magnetic resonance imaging was used to measure total brain volume, brain cortical thickness, brain white matter integrity (or health), and brain white matter hyperintensities. The study showed that people who have higher general intelligence tend to have larger brains, thicker grey matter on the surface of the brain, and healthier white matter brain connections. The associations are not strong, but some aspects of brain structure do relate to intelligence test scores.


2009 ◽  
Vol 110 (2) ◽  
pp. 289-299 ◽  
Author(s):  
Carlo Giussani ◽  
Franck-Emmanuel Roux ◽  
Lorenzo Bello ◽  
Valérie Lauwers-Cances ◽  
Costanza Papagno ◽  
...  

Object It has been hypothesized that specific brain regions involved in face naming may exist in the brain. To spare these areas and to gain a better understanding of their organization, the authors studied patients who underwent surgery by using direct electrical stimulation mapping for brain tumors, and they compared an object-naming task to a famous face–naming task. Methods Fifty-six patients with brain tumors (39 and 17 in the left and right hemispheres, respectively) and with no significant preoperative overall language deficit were prospectively studied over a 2-year period. Four patients who had a partially selective famous face anomia and 2 with prosopagnosia were not included in the final analysis. Results Face-naming interferences were exclusively localized in small cortical areas (< 1 cm2). Among 35 patients whose dominant left hemisphere was studied, 26 face-naming specific areas (that is, sites of interference in face naming only and not in object naming) were found. These face naming–specific sites were significantly detected in 2 regions: in the left frontal areas of the superior, middle, and inferior frontal gyri (p < 0.001) and in the anterior part of the superior and middle temporal gyri (p < 0.01). Variable patterns of interference were observed (speech arrest, anomia, phonemic, or semantic paraphasia) probably related to the different stages in famous face processing. Only 4 famous face–naming interferences were found in the right hemisphere. Conclusions Relative anatomical segregation of naming categories within language areas was detected. This study showed that famous face naming was preferentially processed in the left frontal and anterior temporal gyri. The authors think it is necessary to adapt naming tasks in neurosurgical patients to the brain region studied.


2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
G. Tan ◽  
D. Arnone ◽  
A.M. McIntosh ◽  
K.P. Ebmeier

Introduction:Velocardiofacial syndrome (VCFS) is a common genetic disorder due to a micro deletion on chromosome 22q11. This region includes several risk-associated genetic variants, including COMT, and VCFS is associated with a substantially increased risk for schizophrenia. As such, VCFS may serve as a valuable model for clarifying the neuroanatomical changes associated with genetic risk for psychosis.Methods:A systematic literature search was conducted. Studies were included if they presented original data and were published by March 2008, compared subjects with VCFS and healthy controls and reported measures of brain regions according to SI units as mean and standard deviation. Data extracted from the studies included diagnosis, demographic variables and IQ. Statistical analysis was conducted using STATA 8.0 supplemented by ‘Metan’ software.Results:Twenty studies were retrieved. All measures were expressed in volumes apart from the corpus callosum (area). Subjects with VCFS showed reduced total brain volume (N=156 versus N=138), ([ES]=1.04, 95% CI:1.40, -0.67), with no significant heterogeneity or publication bias. This reduction was reflected in total hemisphere grey and white matter. Prefrontal, parieto-occipital and temporal cortices appeared to be particularly affected. A number of sub-cortical areas also showed decreased volumes including the hippocampus and putamen. In contrast, callosal areas were increased in VCFS.Conclusion:In relation to controls, subjects with VCFS present with an overall reduction in brain volumes and specific abnormalities in multiple cortical and subcortical brain regions. These abnormalities may explain partly why VCFS is associated with a greatly increased risk of psychosis and other psychiatric disorders.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young-Sil An ◽  
Jung Han Yoon ◽  
Sang Joon Son ◽  
Chang Hyung Hong ◽  
Su Jin Lee ◽  
...  

AbstractLittle is known about whether early-phase PET images of 18F-FP-CIT match those of amyloid PET. Here, we compared early-phase 18F-FP-CIT and 18F-flutemetamol PET images in patients who underwent both within a 1-month interval. The SUVR on early-phase 18F-FP-CIT PET (median, 0.86) was significantly lower than that of 18F-flutemetamol PET (median, 0.91, p < 0.001) for total brain regions including all cerebral lobes and central structures. This significant difference persisted for each brain region except central structures (p = 0.232). The SUVR of total brain regions obtained from early 18F-FP-CIT PET showed a very strong correlation with that of 18F-flutemetamol PET (rho = 0.80, p < 0.001). Among the kinetic parameters, only R1 showed a statistically significant correlation between the two techniques for all brain regions (rho = 0.89, p < 0.001). R1 from 18F-FP-CIT (median, 0.77) was significantly lower in all areas of the brain compared to R1 from 18F-flutemetamol PET (median, 0.81, p < 0.001).18F-FP-CIT demonstrated lower uptake in cortical brain regions than 18F-flutemetamol on early-phase PET. However, both early-phase PETs demonstrated significant correlation of uptake.


Author(s):  
Andrew C. Papanicolaou

This chapter focuses on the search for mnemonic traces of concepts that are thought to exist in the form of neuronal circuits in the brain. It begins with a review of the evidence derived from observations of the effects of focal brain lesions suggesting that there are several brain regions specialized for recognizing objects belonging to different categories. It then considers brain areas that have been identified through functional neuroimaging, including the fusiform face area, the parahippocampal place area, and the extra-striate body area. It also examines the specialization of the anterior part of the temporal lobes, especially the left, for naming, and whether these and other brain areas contain mnemonic traces of concepts or traces of cardinal concept features. Finally, it discusses the “top-down” activation of category-specific areas and the idea of distributed storage of concept features.


2020 ◽  
Vol 3 ◽  
Author(s):  
Jonathan Dietrich ◽  
Zoe Guckien ◽  
MaKayla Picklesimer ◽  
Christina Sparks ◽  
David Haas ◽  
...  

Background/Objective: Previous small studies have shown that prenatal opioid-exposed (POE) infants and older children display decreased cerebral, cerebellar, or subcortical brain volumes. However, these studies are plagued by suboptimal reference standards or were unable to correct for the influence of other environmental factors in older children. Therefore, our goal was to study differences in brain volume of POE infants when compared to a geographically matched population. We hypothesized that there will be a significant decrease in total brain volume of the POE infants in comparison to the non-opioid exposed control infants, including a reduction in the cerebellar volume.    Methods: This was an IRB approved prospective study of mothers and infants with POE and controls without POE. All recruited infants underwent MRI scans of the brain before they reached a corrected age of 2 months. The T1-weighted MRI images were analyzed by Infant FreeSurfer and segmented into ROIs. The segmentations were manually checked and edited. An ANOVA analysis was performed to compare the cerebellar and total brain volume datasets. We corrected for gender, corrected gestational age at MRI scan, and total brain volume where necessary.     Results: 42 infants were included in the study, 21 with POE and 21 control infants. There was a significant difference in the mean gestational age of POE infants (38.28±2.13) compared to control infants (39.42±0.72). On quantitative analysis, the POE group had a significantly reduced total brain and supratentorial volume in comparison to the controls. The cerebellar volume was also significantly smaller in POE, but this significance did not persist when the total brain volume was included in the model.     Conclusion: The supratentorial region is affected disproportionately more than the cerebellum in POE. Specific reductions in cortical, subcortical, and white matter volume need to be further investigated and their influence on developmental outcomes need to be studied. 


2021 ◽  
Author(s):  
Zhuoting Zhu ◽  
Wenyi Hu ◽  
Huan Liao ◽  
Danli Shi ◽  
Zachary Tan ◽  
...  

AbstractObjectiveTo investigate the association of visual impairment (VI) with brain structures in the UK Biobank Study.MethodsThe UK Biobank Study is a large prospective study that recruited more than 500,000 participants aged 40-69 from 2006 to 2010 across the UK. Visual acuity (VA) of worse than 0.3 LogMAR units (Snellen 20/40) was defined as VI. Structural magnetic resonance imaging (MRI) data were obtained using a 3.0-T MRI imager. Volumetric measures of five global brain volumes (total brain volume, total grey matter, total white matter, cerebrospinal fluid (CSF), brain stem) and the volumes of seven specific brain region (thalamus, caudate nucleus, basal ganglia, pallidum, hippocampus, amygdala and nucleus accumbens) were included in the present analysis. Multivariable linear regression was used to investigate the association of VI with global and specific brain volumes.ResultsA total of 8976 participants free of neurological disorders at baseline assessment were included for the present analysis. The prevalence of VI was 0.02% (n=181). After adjusting for a range of cofounding factors, VI was significantly associated with decreased volumes of the total brain (β = -0.12, 95% confidence interval (CI) -0.23 to 0.00, P = 0.049), thalamus (β = -0.16, 95% CI -0.18 to -0.04, P = 0.010), caudatenucleus (β = -0.14, 95% CI -0.27 to 0.00, P = 0.046), pallidum (β = -0.15, 95% CI-0.27 to -0.02, P = 0.028) and amygdala (β = -0.18, 95% CI -0.31 to -0.04, P = 0.012).InterpretationWe found that VI is associated with a decrease in total brain volumes and the volumes of specific brain regions implicated in neurodegenerative diseases.


2020 ◽  
Vol 21 ◽  
Author(s):  
Sayed Md Mumtaz ◽  
Gautam Bhardwaj ◽  
Shikha Goswami ◽  
Rajiv Kumar Tonk ◽  
Ramesh K. Goyal ◽  
...  

: The Glioblastoma Multiforme (GBM; grade IV astrocytoma) exhort tumor of star-shaped glial cell in the brain. It is a fast-growing tumor that spreads to nearby brain regions specifically to cerebral hemispheres in frontal and temporal lobes. The etiology of GBM is unknown, but major risk factors are genetic disorder like neurofibromatosis and schwanomatosis which develop the tumor in the nervous system. The management of GBM with chemo-radio therapy leads to resistance and current drug regimen like Temozolomide (TMZ) is less efficacious. The reasons behind failure of drugs are due to DNA alkylation in cell cycle by enzyme DNA guanidase and mitochondrial dysfunction. Naturally occurring bio-active compounds from plants known as phytochemicals, serve as vital sources for anti-cancer drugs. Some typical examples include taxol analogs, vinca alkaloids such as vincristine, vinblastine, podophyllotoxin analogs, camptothecin, curcumin, aloe emodin, quercetin, berberine e.t.c. These phytochemicals often act via regulating molecular pathways which are implicated in growth and progression of cancers. However the challenges posed by the presence of BBB/BBTB to restrict passage of these phytochemicals, culminates in their low bioavailability and relative toxicity. In this review we integrated nanotech as novel drug delivery system to deliver phytochemicals from traditional medicine to the specific site within the brain for the management of GBM.


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