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1.
Zhonghua Yan Ke Za Zhi ; 60(6): 528-536, 2024 Jun 11.
Article in Chinese | MEDLINE | ID: mdl-38825952

ABSTRACT

Objective: To explore the changes in gray matter volume of the cerebral cortex in patients with intermittent exotropia (IXT) using the voxel-based analysis and to analyze the correlation between these changes and clinical manifestations. Methods: This was a cross-sectional study. A collection of 15 consecutive patients diagnosed with IXT at Tianjin Eye Hospital from March 2021 to May 2022 formed the exotropia group, which comprised 8 males and 7 females, with an average age of (23.5±5.2) years. Ten healthy individuals, 3 males and 7 females, with an average age of (27.0±7.5) years, were selected as the control group. All participants underwent assessments of exotropia severity and Titmus stereoacuity. Three-dimensional high-resolution brain images were obtained through MRI scans. Voxel-based morphometry was employed to preprocess the MRI data, and the SPM toolbox in MATLAB was utilized to analyze differences of images between the two groups. Regions of interest (ROI) with structural abnormalities in the gray matter volume analysis were selected, and the ratio of gray matter voxel values in the ROI to the mean gray matter voxel values of the whole brain for each participant was calculated using the MarsBaR software. The correlation between this ratio and exotropia severity as well as the common logarithm of Titmus stereoacuity was analyzed. Results: The differences in age, gender distribution, and refractive error between the two groups were not statistically significant (all P>0.05). However, there were statistically significant differences in the degree of strabismus and Titmus stereoacuity (both P<0.001). Compared to the control group, patients in the strabismus group exhibited decreased gray matter volume in several brain regions, including the wedges of the medial surface of the cerebral hemisphere (decreased by 89 voxels), the left lingual gyrus (decreased by 176 voxels), the left calcarine sulcus V3 area (decreased by 30 voxels), the central anterior gyrus of the right frontal lobe (decreased by 192 voxels), the gray matter of the left hippocampal gyrus (decreased by 20 voxels), and the bilateral lateral geniculate nuclei (decreased by 100 and 40 voxels on the left and right sides, respectively). These differences were all statistically significant (all P<0.001). Additionally, there was an increase in gray matter volume in several brain regions, including the bilateral caudate nuclei (increased by 60 and 76 voxels on the left and right sides, respectively) and the left precentral gyrus (increased by 36 voxels). These differences were also statistically significant (all P<0.001). A group-level analysis identified 10 brain regions with structural differences between the two groups, which were used as ROI. The gray matter volume ratio was negatively correlated with the degree of exotropia (all P<0.05) in the ROI of the left wedges (r=-0.670), left calcarine sulcus V3 area (r=-0.610), and left lingual gyrus (r=-0.684). The gray matter volume ratio was negatively correlated with lgTS (all P<0.05) in the ROI of the left wedges (r=-0.568) and the central anterior gyrus of the right frontal lobe (r=-0.563). Conclusions: Patients with IXT exhibit decreased gray matter volume in the horizontal connection areas between the primary visual cortices V1 and V2. The reduction in gray matter volume of the lingual gyrus and the dorsal visual pathway V3 area becomes more pronounced with increasing exotropia severity, while the gray matter volume of the precentral gyrus (BA6 area) decreases with worsening stereoacuity.


Subject(s)
Cerebral Cortex , Exotropia , Gray Matter , Magnetic Resonance Imaging , Humans , Male , Female , Gray Matter/diagnostic imaging , Magnetic Resonance Imaging/methods , Exotropia/diagnostic imaging , Cross-Sectional Studies , Young Adult , Adult , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/pathology , Case-Control Studies
2.
Hum Brain Mapp ; 45(8): e26682, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38825977

ABSTRACT

Multivariate techniques better fit the anatomy of complex neuropsychiatric disorders which are characterized not by alterations in a single region, but rather by variations across distributed brain networks. Here, we used principal component analysis (PCA) to identify patterns of covariance across brain regions and relate them to clinical and demographic variables in a large generalizable dataset of individuals with bipolar disorders and controls. We then compared performance of PCA and clustering on identical sample to identify which methodology was better in capturing links between brain and clinical measures. Using data from the ENIGMA-BD working group, we investigated T1-weighted structural MRI data from 2436 participants with BD and healthy controls, and applied PCA to cortical thickness and surface area measures. We then studied the association of principal components with clinical and demographic variables using mixed regression models. We compared the PCA model with our prior clustering analyses of the same data and also tested it in a replication sample of 327 participants with BD or schizophrenia and healthy controls. The first principal component, which indexed a greater cortical thickness across all 68 cortical regions, was negatively associated with BD, BMI, antipsychotic medications, and age and was positively associated with Li treatment. PCA demonstrated superior goodness of fit to clustering when predicting diagnosis and BMI. Moreover, applying the PCA model to the replication sample yielded significant differences in cortical thickness between healthy controls and individuals with BD or schizophrenia. Cortical thickness in the same widespread regional network as determined by PCA was negatively associated with different clinical and demographic variables, including diagnosis, age, BMI, and treatment with antipsychotic medications or lithium. PCA outperformed clustering and provided an easy-to-use and interpret method to study multivariate associations between brain structure and system-level variables. PRACTITIONER POINTS: In this study of 2770 Individuals, we confirmed that cortical thickness in widespread regional networks as determined by principal component analysis (PCA) was negatively associated with relevant clinical and demographic variables, including diagnosis, age, BMI, and treatment with antipsychotic medications or lithium. Significant associations of many different system-level variables with the same brain network suggest a lack of one-to-one mapping of individual clinical and demographic factors to specific patterns of brain changes. PCA outperformed clustering analysis in the same data set when predicting group or BMI, providing a superior method for studying multivariate associations between brain structure and system-level variables.


Subject(s)
Bipolar Disorder , Magnetic Resonance Imaging , Obesity , Principal Component Analysis , Humans , Bipolar Disorder/diagnostic imaging , Bipolar Disorder/drug therapy , Bipolar Disorder/pathology , Adult , Female , Male , Magnetic Resonance Imaging/methods , Middle Aged , Obesity/diagnostic imaging , Schizophrenia/diagnostic imaging , Schizophrenia/pathology , Schizophrenia/drug therapy , Schizophrenia/physiopathology , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/pathology , Cluster Analysis , Young Adult , Brain/diagnostic imaging , Brain/pathology
4.
Transl Psychiatry ; 14(1): 235, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38830892

ABSTRACT

There is a lack of knowledge regarding the relationship between proneness to dimensional psychopathological syndromes and the underlying pathogenesis across major psychiatric disorders, i.e., Major Depressive Disorder (MDD), Bipolar Disorder (BD), Schizoaffective Disorder (SZA), and Schizophrenia (SZ). Lifetime psychopathology was assessed using the OPerational CRITeria (OPCRIT) system in 1,038 patients meeting DSM-IV-TR criteria for MDD, BD, SZ, or SZA. The cohort was split into two samples for exploratory and confirmatory factor analyses. All patients were scanned with 3-T MRI, and data was analyzed with the CAT-12 toolbox in SPM12. Psychopathological factor scores were correlated with gray matter volume (GMV) and cortical thickness (CT). Finally, factor scores were used for exploratory genetic analyses including genome-wide association studies (GWAS) and polygenic risk score (PRS) association analyses. Three factors (paranoid-hallucinatory syndrome, PHS; mania, MA; depression, DEP) were identified and cross-validated. PHS was negatively correlated with four GMV clusters comprising parts of the hippocampus, amygdala, angular, middle occipital, and middle frontal gyri. PHS was also negatively associated with the bilateral superior temporal, left parietal operculum, and right angular gyrus CT. No significant brain correlates were observed for the two other psychopathological factors. We identified genome-wide significant associations for MA and DEP. PRS for MDD and SZ showed a positive effect on PHS, while PRS for BD showed a positive effect on all three factors. This study investigated the relationship of lifetime psychopathological factors and brain morphometric and genetic markers. Results highlight the need for dimensional approaches, overcoming the limitations of the current psychiatric nosology.


Subject(s)
Bipolar Disorder , Depressive Disorder, Major , Genome-Wide Association Study , Gray Matter , Magnetic Resonance Imaging , Psychotic Disorders , Schizophrenia , Humans , Male , Female , Adult , Bipolar Disorder/genetics , Bipolar Disorder/pathology , Bipolar Disorder/diagnostic imaging , Depressive Disorder, Major/genetics , Depressive Disorder, Major/diagnostic imaging , Depressive Disorder, Major/pathology , Schizophrenia/genetics , Schizophrenia/pathology , Schizophrenia/diagnostic imaging , Psychotic Disorders/genetics , Psychotic Disorders/diagnostic imaging , Psychotic Disorders/pathology , Gray Matter/pathology , Gray Matter/diagnostic imaging , Middle Aged , Factor Analysis, Statistical , Brain/pathology , Brain/diagnostic imaging , Psychopathology , Multifactorial Inheritance/genetics , Cerebral Cortex/pathology , Cerebral Cortex/diagnostic imaging
5.
Rev. neurol. (Ed. impr.) ; 78(7): 199-207, Ene-Jun, 2024. ilus, graf
Article in Spanish | IBECS | ID: ibc-232186

ABSTRACT

Introducción: El neurocientífico español Justo Gonzalo y Rodríguez-Leal (1910-1986) investiga la organización funcional de la corteza cerebral durante más de cuatro décadas. Sus hallazgos le llevan a formular una teoría neurofisiológica basada en las leyes de la excitabilidad nerviosa, que denomina dinámica cerebral. En el presente trabajo se expone de forma cronológica cómo surgen las principales ideas sobre las que se articula.Desarrollo: En 1939 Gonzalo observa los denominados fenómenos de acción dinámica: desfasamiento, facilitación y repercusión cerebral. Le siguen dos principios: efecto cerebral de la lesión según la magnitud y posición (1941), y organización sensorial, según un desarrollo espiral (1947). Paralelamente, caracteriza lo que llama el síndrome central de la corteza cerebral. En la década de los cincuenta desarrolla los conceptos de gradiente cortical, similitud y alometría. En contraposición a las concepciones modulares de la corteza cerebral, en las que una región es responsable de una función, Gonzalo expresa que ‘los gradientes corticales dan la localización de los sistemas mientras la similitud y alometría revelan su trama funcional’.Conclusiones: La teoría de dinámica cerebral se articula en dos etapas. La primera (de 1938 a 1950) se caracteriza por una importante base clínica con observación de nuevos fenómenos y formulación de nuevos conceptos. La segunda (de 1950 a 1960) incluye la introducción de conceptos de mayor alcance, como el gradiente funcional cortical, y leyes de alometría que se basan en un cambio de escala. Actualmente, varios autores consideran que el concepto de gradiente es clave para entender la organización cerebral.(AU)


Introduction: The Spanish neuroscientist Justo Gonzalo y Rodríguez-Leal (1910-1986) investigated the functional organisation of the cerebral cortex over more than four decades. His findings led him to formulate a neurophysiological theory based on the laws of nervous excitability, which he called brain dynamics. This paper presents in chronological order how the main ideas on which it is based arose.Development: In 1939, Gonzalo observed the phenomena of dynamic action: asynchrony or disaggregation, facilitation and cerebral repercussion. This was followed by two principles: the cerebral effect of lesions according to their magnitude and position (1941), and spiral development of the sensory field (1947). At the same time, he characterised what he called the central syndrome of the cerebral cortex. In the 1950s he developed the concepts of the cortical gradient, similarity and allometry. In contrast to modular conceptions of the cerebral cortex, in which one region is responsible for one function, Gonzalo argued that ‘cortical gradients provide the location of systems, while similarity and allometry reveal their functional mechanism.’Conclusions: The theory of brain dynamics was established in two stages. The first (between 1938 and 1950) had an important clinical foundation, involving the observation of new phenomena and the formulation of new concepts. The second (between 1950 and 1960) included the introduction of more far-reaching concepts, such as the functional cortical gradient, and allometry laws based on a change of scale. Today, various authors believe that the concept of the gradient is crucial for understanding how the brain is organised.(AU)


Subject(s)
Humans , Male , Female , Cerebral Cortex , Cerebral Cortex/anatomy & histology , Neurology/history , Cerebrum/anatomy & histology , Neurophysiology
6.
Neuron ; 112(9): 1373-1375, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38697018

ABSTRACT

Maternal well-being is important for the development of the fetus, with a key influence on its nervous system. In this issue of Neuron, Krontira et al.1 implicate glucocorticoids, the stress hormones, in the regulation of neural stem cell identity and proliferation, with long-lasting consequences on brain architecture and educational attainment.


Subject(s)
Glucocorticoids , Neurogenesis , Humans , Glucocorticoids/pharmacology , Neurogenesis/drug effects , Neurogenesis/physiology , Neurons/drug effects , Neurons/physiology , Cerebral Cortex/drug effects , Cerebral Cortex/cytology , Neural Stem Cells/drug effects
7.
Hum Brain Mapp ; 45(7): e26703, 2024 May.
Article in English | MEDLINE | ID: mdl-38716714

ABSTRACT

The default mode network (DMN) lies towards the heteromodal end of the principal gradient of intrinsic connectivity, maximally separated from the sensory-motor cortex. It supports memory-based cognition, including the capacity to retrieve conceptual and evaluative information from sensory inputs, and to generate meaningful states internally; however, the functional organisation of DMN that can support these distinct modes of retrieval remains unclear. We used fMRI to examine whether activation within subsystems of DMN differed as a function of retrieval demands, or the type of association to be retrieved, or both. In a picture association task, participants retrieved semantic associations that were either contextual or emotional in nature. Participants were asked to avoid generating episodic associations. In the generate phase, these associations were retrieved from a novel picture, while in the switch phase, participants retrieved a new association for the same image. Semantic context and emotion trials were associated with dissociable DMN subnetworks, indicating that a key dimension of DMN organisation relates to the type of association being accessed. The frontotemporal and medial temporal DMN showed a preference for emotional and semantic contextual associations, respectively. Relative to the generate phase, the switch phase recruited clusters closer to the heteromodal apex of the principal gradient-a cortical hierarchy separating unimodal and heteromodal regions. There were no differences in this effect between association types. Instead, memory switching was associated with a distinct subnetwork associated with controlled internal cognition. These findings delineate distinct patterns of DMN recruitment for different kinds of associations yet common responses across tasks that reflect retrieval demands.


Subject(s)
Default Mode Network , Emotions , Magnetic Resonance Imaging , Mental Recall , Semantics , Humans , Male , Female , Adult , Young Adult , Emotions/physiology , Default Mode Network/physiology , Default Mode Network/diagnostic imaging , Mental Recall/physiology , Cerebral Cortex/physiology , Cerebral Cortex/diagnostic imaging , Nerve Net/physiology , Nerve Net/diagnostic imaging , Brain Mapping , Pattern Recognition, Visual/physiology
8.
Cereb Cortex ; 34(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38706137

ABSTRACT

Schizophrenia has been considered to exhibit sex-related clinical differences that might be associated with distinctly abnormal brain asymmetries between sexes. One hundred and thirty-two antipsychotic-naïve first-episode patients with schizophrenia and 150 healthy participants were recruited in this study to investigate whether cortical asymmetry would exhibit sex-related abnormalities in schizophrenia. After a 1-yr follow-up, patients were rescanned to obtain the effect of antipsychotic treatment on cortical asymmetry. Male patients were found to show increased lateralization index while female patients were found to exhibit decreased lateralization index in widespread regions when compared with healthy participants of the corresponding sex. Specifically, the cortical asymmetry of male and female patients showed contrary trends in the cingulate, orbitofrontal, parietal, temporal, occipital, and insular cortices. This result suggested male patients showed a leftward shift of asymmetry while female patients showed a rightward shift of asymmetry in these above regions that related to language, vision, emotion, and cognition. Notably, abnormal lateralization indices remained stable after antipsychotic treatment. The contrary trends in asymmetry between female and male patients with schizophrenia together with the persistent abnormalities after antipsychotic treatment suggested the altered brain asymmetries in schizophrenia might be sex-related disturbances, intrinsic, and resistant to the effect of antipsychotic therapy.


Subject(s)
Antipsychotic Agents , Cerebral Cortex , Functional Laterality , Magnetic Resonance Imaging , Schizophrenia , Sex Characteristics , Humans , Female , Male , Schizophrenia/drug therapy , Schizophrenia/pathology , Schizophrenia/diagnostic imaging , Schizophrenia/physiopathology , Adult , Cerebral Cortex/diagnostic imaging , Young Adult , Antipsychotic Agents/therapeutic use , Functional Laterality/physiology , Adolescent , Brain Mapping
9.
Commun Biol ; 7(1): 550, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719883

ABSTRACT

Perceptual and cognitive processing relies on flexible communication among cortical areas; however, the underlying neural mechanism remains unclear. Here we report a mechanism based on the realistic spatiotemporal dynamics of propagating wave patterns in neural population activity. Using a biophysically plausible, multiarea spiking neural circuit model, we demonstrate that these wave patterns, characterized by their rich and complex dynamics, can account for a wide variety of empirically observed neural processes. The coordinated interactions of these wave patterns give rise to distributed and dynamic communication (DDC) that enables flexible and rapid routing of neural activity across cortical areas. We elucidate how DDC unifies the previously proposed oscillation synchronization-based and subspace-based views of interareal communication, offering experimentally testable predictions that we validate through the analysis of Allen Institute Neuropixels data. Furthermore, we demonstrate that DDC can be effectively modulated during attention tasks through the interplay of neuromodulators and cortical feedback loops. This modulation process explains many neural effects of attention, underscoring the fundamental functional role of DDC in cognition.


Subject(s)
Attention , Models, Neurological , Attention/physiology , Humans , Cerebral Cortex/physiology , Animals , Nerve Net/physiology , Visual Perception/physiology , Neurons/physiology , Cognition/physiology
10.
Neurosci Lett ; 832: 137814, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38723760

ABSTRACT

Galanin (Gal) is a neuropeptide with the potential to ameliorate cortical spreading depolarization (CSD), an electrophysiological phenomenon occurring after brain injury or in migraine aura. Gal is expressed in all cortical neurons both in rat and in mouse cortices. Here we investigated whether the effect of Gal on CSD previously described in the rat is conserved in the mouse cortex. In rats, the topical application of Gal to the cortex for 1 h did not induce any change in CSD amplitudes, propagation velocity, or threshold of elicitation. Rather, topical application of Gal for 3 h was necessary to obtain a significant decrease in these CSD parameters and to develop a remarkable increase in the KCl threshold to elicit a CSD in rat cortex. In contrast, the topical application of Gal on cortical surface for 1 h in mice was sufficient to significantly attenuate CSD amplitudes and increase threshold. A thinner cortex, a faster diffusion or different affinity/expression of receptors for Gal are possible reasons to explain this difference in the time course between rats and mice. Our data are relevant to postulate Gal as a potential target for inhibition of CSD under pathological situations such as stroke or ischemia. SIGNIFICANCE STATEMENT: The neuropeptide Galanin (Gal) is expressed in all neurons throughout the cerebral cortex, both in rats and mice, and is able to reduce or even inhibit Cortical Spreading Depolarization, thus, Gal has the potential to control neuronal excitability that may identify Gal as a target in drug development against CSD.


Subject(s)
Cerebral Cortex , Cortical Spreading Depression , Galanin , Animals , Galanin/pharmacology , Galanin/metabolism , Cortical Spreading Depression/drug effects , Cortical Spreading Depression/physiology , Male , Mice , Rats , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Mice, Inbred C57BL , Neurons/drug effects , Neurons/metabolism , Rats, Wistar
11.
J Affect Disord ; 345: 410-418, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38706461

ABSTRACT

A persistent and influential barrier to effective cognitive-behavioral therapy (CBT) for patients with hoarding disorder (HD) is treatment retention and compliance. Recent research has suggested that HD patients have abnormal brain activity identified by functional magnetic resonance (fMRI) in regions often engaged for executive functioning (e.g., right superior frontal gyrus, anterior insula, and anterior cingulate), which raises questions about whether these abnormalities could relate to patients' ability to attend, understand, and engage in HD treatment. We examined data from 74 HD-diagnosed adults who completed fMRI-measured brain activity during a discarding task designed to elicit symptom-related brain dysfunction, exploring which regions' activity might predict treatment compliance variables, including treatment engagement (within-session compliance), homework completion (between-session compliance), and treatment attendance. Brain activity that was significantly related to within- and between-session compliance was found largely in insula, parietal, and premotor areas. No brain regions were associated with treatment attendance. The results add to findings from prior research that have found prefrontal, cingulate, and insula activity abnormalities in HD by suggesting that some aspects of HD brain dysfunction might play a role in preventing the engagement needed for therapeutic benefit.


Subject(s)
Cognitive Behavioral Therapy , Hoarding Disorder , Magnetic Resonance Imaging , Psychotherapy, Group , Humans , Hoarding Disorder/therapy , Hoarding Disorder/physiopathology , Male , Female , Middle Aged , Adult , Brain/physiopathology , Brain/diagnostic imaging , Patient Compliance/statistics & numerical data , Cerebral Cortex/physiopathology , Cerebral Cortex/diagnostic imaging , Aged , Executive Function/physiology , Gyrus Cinguli/physiopathology , Gyrus Cinguli/diagnostic imaging
12.
PeerJ ; 12: e17313, 2024.
Article in English | MEDLINE | ID: mdl-38708344

ABSTRACT

Background: Humans continuously maintain and adjust posture during gait, standing, and sitting. The difficulty of postural control is reportedly increased during unstable stances, such as unipedal standing and with closed eyes. Although balance is slightly impaired in healthy young adults in such unstable stances, they rarely fall. The brain recognizes the change in sensory inputs and outputs motor commands to the musculoskeletal system. However, such changes in cortical activity associated with the maintenance of balance following periods of instability require further clarified. Methods: In this study, a total of 15 male participants performed two postural control tasks and the center of pressure displacement and electroencephalogram were simultaneously measured. In addition, the correlation between amplitude of center of pressure displacement and power spectral density of electroencephalogram was analyzed. Results: The movement of the center of pressure was larger in unipedal standing than in bipedal standing under both eye open and eye closed conditions. It was also larger under the eye closed condition compared with when the eyes were open in unipedal standing. The amplitude of high-frequency bandwidth (1-3 Hz) of the center of pressure displacement was larger during more difficult postural tasks than during easier ones, suggesting that the continuous maintenance of posture was required. The power spectral densities of the theta activity in the frontal area and the gamma activity in the parietal area were higher during more difficult postural tasks than during easier ones across two postural control tasks, and these correlate with the increase in amplitude of high-frequency bandwidth of the center of pressure displacement. Conclusions: Taken together, specific activation patterns of the neocortex are suggested to be important for the postural maintenance during unstable stances.


Subject(s)
Electroencephalography , Postural Balance , Humans , Postural Balance/physiology , Male , Young Adult , Adult , Posture/physiology , Cerebral Cortex/physiology , Standing Position
13.
Biomed Khim ; 70(2): 83-88, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38711407

ABSTRACT

The toxic effect of ethanol on the cerebral cortex and protective effects of omega-3 fatty acids against this neurotoxicity were investigated. Twenty eight male Wistar-albino rats were divided into 4 groups. Rats of the ethanol and ethanol withdrawal groups were treated with ethanol (6 g/kg/day) for 15 days. Animals of the ethanol+omega-3 group received omega-3 fatty acids (400 mg/kg daily) and ethanol. In rats of the ethanol group SOD activity was lower than in animals of the control group. In rats treated with omega-3 fatty acids along with ethanol SOD, activity increased. GSH-Px activity and MDA levels in animals of all groups were similar. In ethanol treated rats NO levels significantly decreased as compared to the animals of the control group (6.45±0.24 nmol/g vs 11.05±0.53 nmol/g, p.


Subject(s)
Cerebral Cortex , Ethanol , Fatty Acids, Omega-3 , Nitric Oxide , Rats, Wistar , Superoxide Dismutase , Animals , Male , Rats , Fatty Acids, Omega-3/pharmacology , Cerebral Cortex/metabolism , Cerebral Cortex/drug effects , Nitric Oxide/metabolism , Superoxide Dismutase/metabolism , Glutathione Peroxidase/metabolism , Antioxidants/pharmacology , Malondialdehyde/metabolism
14.
Neuron ; 112(10): 1611-1625, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38754373

ABSTRACT

Consciousness can be conceptualized as varying along at least two dimensions: the global state of consciousness and the content of conscious experience. Here, we highlight the cellular and systems-level contributions of the thalamus to conscious state and then argue for thalamic contributions to conscious content, including the integrated, segregated, and continuous nature of our experience. We underscore vital, yet distinct roles for core- and matrix-type thalamic neurons. Through reciprocal interactions with deep-layer cortical neurons, matrix neurons support wakefulness and determine perceptual thresholds, whereas the cortical interactions of core neurons maintain content and enable perceptual constancy. We further propose that conscious integration, segregation, and continuity depend on the convergent nature of corticothalamic projections enabling dimensionality reduction, a thalamic reticular nucleus-mediated divisive normalization-like process, and sustained coherent activity in thalamocortical loops, respectively. Overall, we conclude that the thalamus plays a central topological role in brain structures controlling conscious experience.


Subject(s)
Consciousness , Thalamus , Thalamus/physiology , Consciousness/physiology , Humans , Animals , Neural Pathways/physiology , Neurons/physiology , Cerebral Cortex/physiology , Wakefulness/physiology
15.
Hum Brain Mapp ; 45(7): e26666, 2024 May.
Article in English | MEDLINE | ID: mdl-38726831

ABSTRACT

Advanced meditation such as jhana meditation can produce various altered states of consciousness (jhanas) and cultivate rewarding psychological qualities including joy, peace, compassion, and attentional stability. Mapping the neurobiological substrates of jhana meditation can inform the development and application of advanced meditation to enhance well-being. Only two prior studies have attempted to investigate the neural correlates of jhana meditation, and the rarity of adept practitioners has largely restricted the size and extent of these studies. Therefore, examining the consistency and reliability of observed brain responses associated with jhana meditation can be valuable. In this study, we aimed to characterize functional magnetic resonance imaging (fMRI) reliability within a single subject over repeated runs in canonical brain networks during jhana meditation performed by an adept practitioner over 5 days (27 fMRI runs) inside an ultra-high field 7 Tesla MRI scanner. We found that thalamus and several cortical networks, that is, the somatomotor, limbic, default-mode, control, and temporo-parietal, demonstrated good within-subject reliability across all jhanas. Additionally, we found that several other relevant brain networks (e.g., attention, salience) showed noticeable increases in reliability when fMRI measurements were adjusted for variability in self-reported phenomenology related to jhana meditation. Overall, we present a preliminary template of reliable brain areas likely underpinning core neurocognitive elements of jhana meditation, and highlight the utility of neurophenomenological experimental designs for better characterizing neuronal variability associated with advanced meditative states.


Subject(s)
Magnetic Resonance Imaging , Meditation , Nerve Net , Humans , Reproducibility of Results , Nerve Net/physiology , Nerve Net/diagnostic imaging , Adult , Male , Female , Brain/physiology , Brain/diagnostic imaging , Cerebral Cortex/physiology , Cerebral Cortex/diagnostic imaging
16.
Hum Brain Mapp ; 45(7): e26700, 2024 May.
Article in English | MEDLINE | ID: mdl-38726799

ABSTRACT

The post-movement beta rebound has been studied extensively using magnetoencephalography (MEG) and is reliably modulated by various task parameters as well as illness. Our recent study showed that rebounds, which we generalise as "post-task responses" (PTRs), are a ubiquitous phenomenon in the brain, occurring across the cortex in theta, alpha, and beta bands. Currently, it is unknown whether PTRs following working memory are driven by transient bursts, which are moments of short-lived high amplitude activity, similar to those that drive the post-movement beta rebound. Here, we use three-state univariate hidden Markov models (HMMs), which can identify bursts without a priori knowledge of frequency content or response timings, to compare bursts that drive PTRs in working memory and visuomotor MEG datasets. Our results show that PTRs across working memory and visuomotor tasks are driven by pan-spectral transient bursts. These bursts have very similar spectral content variation over the cortex, correlating strongly between the two tasks in the alpha (R2 = .89) and beta (R2 = .53) bands. Bursts also have similar variation in duration over the cortex (e.g., long duration bursts occur in the motor cortex for both tasks), strongly correlating over cortical regions between tasks (R2 = .56), with a mean over all regions of around 300 ms in both datasets. Finally, we demonstrate the ability of HMMs to isolate signals of interest in MEG data, such that the HMM probability timecourse correlates more strongly with reaction times than frequency filtered power envelopes from the same brain regions. Overall, we show that induced PTRs across different tasks are driven by bursts with similar characteristics, which can be identified using HMMs. Given the similarity between bursts across tasks, we suggest that PTRs across the cortex may be driven by a common underlying neural phenomenon.


Subject(s)
Magnetoencephalography , Memory, Short-Term , Humans , Memory, Short-Term/physiology , Adult , Male , Female , Young Adult , Markov Chains , Psychomotor Performance/physiology , Cerebral Cortex/physiology , Movement/physiology , Beta Rhythm/physiology
17.
Article in English | MEDLINE | ID: mdl-38748531

ABSTRACT

Brain-heart interactions (BHI) are critical for generating and processing emotions, including anxiety. Understanding specific neural correlates would be instrumental for greater comprehension and potential therapeutic interventions of anxiety disorders. While prior work has implicated the pontine structure as a central processor in cardiac regulation in anxiety, the distributed nature of anxiety processing across the cortex remains elusive. To address this, we performed a whole-brain-heart analysis using the full frequency directed transfer function to study resting-state spectral differences in BHI between high and low anxiety groups undergoing fMRI scans. Our findings revealed a hemispheric asymmetry in low-frequency interplay (0.05 Hz - 0.15 Hz) characterized by ascending BHI to the left insula and descending BHI from the right insula. Furthermore, we provide evidence supporting the "pacemaker hypothesis", highlighting the pons' function in regulating cardiac activity. Higher frequency interplay (0.2 Hz - 0.4Hz) demonstrate a preference for ascending interactions, particularly towards ventral prefrontal cortical activity in high anxiety groups, suggesting the heart's role in triggering a cognitive response to regulate anxiety. These findings highlight the impact of anxiety on BHI, contributing to a better understanding of its effect on the resting-state fMRI signal, with further implications for potential therapeutic interventions in treating anxiety disorders.


Subject(s)
Anxiety , Brain , Magnetic Resonance Imaging , Humans , Male , Female , Adult , Anxiety/psychology , Anxiety/physiopathology , Young Adult , Brain/diagnostic imaging , Brain/physiopathology , Heart/diagnostic imaging , Heart Rate/physiology , Functional Laterality/physiology , Prefrontal Cortex/diagnostic imaging , Prefrontal Cortex/physiopathology , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/physiopathology , Anxiety Disorders/diagnostic imaging , Anxiety Disorders/physiopathology , Anxiety Disorders/psychology
19.
Nat Commun ; 15(1): 4071, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38778078

ABSTRACT

Adaptive behavior requires integrating prior knowledge of action outcomes and sensory evidence for making decisions while maintaining prior knowledge for future actions. As outcome- and sensory-based decisions are often tested separately, it is unclear how these processes are integrated in the brain. In a tone frequency discrimination task with two sound durations and asymmetric reward blocks, we found that neurons in the medial prefrontal cortex of male mice represented the additive combination of prior reward expectations and choices. The sensory inputs and choices were selectively decoded from the auditory cortex irrespective of reward priors and the secondary motor cortex, respectively, suggesting localized computations of task variables are required within single trials. In contrast, all the recorded regions represented prior values that needed to be maintained across trials. We propose localized and global computations of task variables in different time scales in the cerebral cortex.


Subject(s)
Auditory Cortex , Choice Behavior , Reward , Animals , Male , Choice Behavior/physiology , Mice , Auditory Cortex/physiology , Neurons/physiology , Prefrontal Cortex/physiology , Acoustic Stimulation , Mice, Inbred C57BL , Cerebral Cortex/physiology , Motor Cortex/physiology , Auditory Perception/physiology
20.
BMC Oral Health ; 24(1): 599, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38778294

ABSTRACT

BACKGROUND: A change in professionals' perspectives on the value of general anesthesia (GA) for pediatric patients, including those with disabilities, medical conditions, severe oral issues, and challenging behaviors. Full-mouth rehabilitation under GA allows for the comprehensive treatment of all oral health problems in a single visit, without requiring the child's active participation. Extensive dental problems are often associated with severe dental pain, which can impact cognitive function, including perception, attention, memory, reasoning, language, communication, and executive functions. Individuals experiencing pain tend to perform less optimally cognitively. AIM: This study aimed to investigate changes in cognition, brain function, and cortical alterations in children who underwent extensive dental rehabilitation under GA. PATIENTS ANDMETHODS: Thirty uncooperative, healthy children aged 6-12 with extensive dental issues were enrolled. Pain levels were assessed using the FLACC and WBFPS scales before treatment, one week after, and three months later. Cognitive assessments, including the WCST, processing speed, digit span, and Trail Making Test, as well as EEG measurements, were also performed. RESULTS: The results showed a significant improvement in pain levels reported by the children or their caregivers after the dental procedures, both at one week and three months. All cognitive measures, such as digit span, processing speed, and WCST performance, demonstrated substantial improvements after the treatment. The Trail Making Test also exhibited statistically significant variations before and after the dental procedures. Additionally, the MOCA test revealed a notable improvement in cognitive skills following the treatment. Furthermore, the EEG power ratio, an indicator of changes in the power balance within each frequency band, showed a statistically significant difference after the dental procedures. CONCLUSION: the findings of this study suggest that full-mouth rehabilitation under GA can lead to improved pain management, as well as enhanced cognitive and brain functions in children. FUTURE PERSPECTIVES: More clinical studies with a longer follow-up period and a different age range of children are required to investigate the connection between brain function and oral rehabilitation involving restorations or occlusion issues.


Subject(s)
Cognition , Pain Measurement , Humans , Child , Male , Female , Cognition/physiology , Mouth Rehabilitation/methods , Anesthesia, General , Electroencephalography , Cerebral Cortex/physiopathology
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