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Nature Communications Jun 2024While human vision spans 220°, traditional functional MRI setups display images only up to central 10-15°. Thus, it remains unknown how the brain represents a scene...
While human vision spans 220°, traditional functional MRI setups display images only up to central 10-15°. Thus, it remains unknown how the brain represents a scene perceived across the full visual field. Here, we introduce a method for ultra-wide angle display and probe signatures of immersive scene representation. An unobstructed view of 175° is achieved by bouncing the projected image off angled-mirrors onto a custom-built curved screen. To avoid perceptual distortion, scenes are created with wide field-of-view from custom virtual environments. We find that immersive scene representation drives medial cortex with far-peripheral preferences, but shows minimal modulation in classic scene regions. Further, scene and face-selective regions maintain their content preferences even with extreme far-periphery stimulation, highlighting that not all far-peripheral information is automatically integrated into scene regions computations. This work provides clarifying evidence on content vs. peripheral preferences in scene representation and opens new avenues to research immersive vision.
Topics: Humans; Visual Cortex; Magnetic Resonance Imaging; Male; Adult; Female; Young Adult; Visual Perception; Photic Stimulation; Brain Mapping; Neuroimaging; Visual Fields; Pattern Recognition, Visual
PubMed: 38942766
DOI: 10.1038/s41467-024-49669-0 -
Science Advances Jun 2024Declined memory is a hallmark of Alzheimer's disease (AD). Experiments in rodents and human postmortem studies suggest that serotonin (5-hydroxytryptamine, 5-HT) plays a...
Declined memory is a hallmark of Alzheimer's disease (AD). Experiments in rodents and human postmortem studies suggest that serotonin (5-hydroxytryptamine, 5-HT) plays a role in memory, but the underlying mechanisms are unknown. Here, we investigate the role of 5-HT 2C receptor (5-HTR) in regulating memory. Transgenic mice expressing a humanized mutation exhibit impaired plasticity of hippocampal ventral CA1 (vCA1) neurons and reduced memory. Further, 5-HT neurons project to and synapse onto vCA1 neurons. Disruption of 5-HT synthesis in vCA1-projecting neurons or deletion of 5-HTRs in the vCA1 impairs neural plasticity and memory. We show that a selective 5-HTR agonist, lorcaserin, improves synaptic plasticity and memory in an AD mouse model. Cumulatively, we demonstrate that hippocampal 5-HTR signaling regulates memory, which may inform the use of 5-HTR agonists in the treatment of dementia.
Topics: Animals; Humans; Receptor, Serotonin, 5-HT2C; Memory; Mice; Mice, Transgenic; Neuronal Plasticity; Alzheimer Disease; Hippocampus; Serotonin; Disease Models, Animal; CA1 Region, Hippocampal; Neurons; Serotonin 5-HT2 Receptor Agonists
PubMed: 38941473
DOI: 10.1126/sciadv.adl2675 -
Science Advances Jun 2024Functional deficits in basal ganglia (BG) circuits contribute to cognitive and motor dysfunctions in alcohol use disorder. Chronic alcohol exposure alters synaptic...
Functional deficits in basal ganglia (BG) circuits contribute to cognitive and motor dysfunctions in alcohol use disorder. Chronic alcohol exposure alters synaptic function and neuronal excitability in the dorsal striatum, but it remains unclear how it affects BG output that is mediated by the substantia nigra pars reticulata (SNr). Here, we describe a neuronal subpopulation-specific synaptic organization of striatal and subthalamic (STN) inputs to the medial and lateral SNr. Chronic alcohol exposure (CIE) potentiated dorsolateral striatum (DLS) inputs but did not change dorsomedial striatum and STN inputs to the SNr. Chemogenetic inhibition of DLS direct pathway neurons revealed an enhanced role for DLS direct pathway neurons in execution of an instrumental lever-pressing task. Overall, we reveal a subregion-specific organization of striatal and subthalamic inputs onto the medial and lateral SNr and find that potentiated DLS-SNr inputs are accompanied by altered BG control of action execution following CIE.
Topics: Animals; Neuronal Plasticity; Basal Ganglia; Substantia Nigra; Ethanol; Corpus Striatum; Male; Mice; Neurons; Alcoholism; Neural Pathways
PubMed: 38941461
DOI: 10.1126/sciadv.adm6951 -
PLoS Biology Jun 2024Comparative research suggests that the hypothalamus is critical in switching between survival behaviors, yet it is unclear if this is the case in humans. Here, we...
Comparative research suggests that the hypothalamus is critical in switching between survival behaviors, yet it is unclear if this is the case in humans. Here, we investigate the role of the human hypothalamus in survival switching by introducing a paradigm where volunteers switch between hunting and escape in response to encounters with a virtual predator or prey. Given the small size and low tissue contrast of the hypothalamus, we used deep learning-based segmentation to identify the individual-specific hypothalamus and its subnuclei as well as an imaging sequence optimized for hypothalamic signal acquisition. Across 2 experiments, we employed computational models with identical structures to explain internal movement generation processes associated with hunting and escaping. Despite the shared structure, the models exhibited significantly different parameter values where escaping or hunting were accurately decodable just by computing the parameters of internal movement generation processes. In experiment 2, multi-voxel pattern analyses (MVPA) showed that the hypothalamus, hippocampus, and periaqueductal gray encode switching of survival behaviors while not encoding simple motor switching outside of the survival context. Furthermore, multi-voxel connectivity analyses revealed a network including the hypothalamus as encoding survival switching and how the hypothalamus is connected to other regions in this network. Finally, model-based fMRI analyses showed that a strong hypothalamic multi-voxel pattern of switching is predictive of optimal behavioral coordination after switching, especially when this signal was synchronized with the multi-voxel pattern of switching in the amygdala. Our study is the first to identify the role of the human hypothalamus in switching between survival behaviors and action organization after switching.
Topics: Humans; Hypothalamus; Magnetic Resonance Imaging; Male; Adult; Female; Young Adult; Hippocampus; Escape Reaction; Deep Learning; Brain Mapping; Periaqueductal Gray
PubMed: 38941452
DOI: 10.1371/journal.pbio.3002624 -
ELife Jun 2024How human prefrontal and insular regions interact while maximizing rewards and minimizing punishments is unknown. Capitalizing on human intracranial recordings, we...
How human prefrontal and insular regions interact while maximizing rewards and minimizing punishments is unknown. Capitalizing on human intracranial recordings, we demonstrate that the functional specificity toward reward or punishment learning is better disentangled by interactions compared to local representations. Prefrontal and insular cortices display non-selective neural populations to rewards and punishments. Non-selective responses, however, give rise to context-specific interareal interactions. We identify a reward subsystem with redundant interactions between the orbitofrontal and ventromedial prefrontal cortices, with a driving role of the latter. In addition, we find a punishment subsystem with redundant interactions between the insular and dorsolateral cortices, with a driving role of the insula. Finally, switching between reward and punishment learning is mediated by synergistic interactions between the two subsystems. These results provide a unifying explanation of distributed cortical representations and interactions supporting reward and punishment learning.
Topics: Humans; Punishment; Reward; Male; Adult; Female; Prefrontal Cortex; Learning; Young Adult; Insular Cortex; Frontal Lobe
PubMed: 38941238
DOI: 10.7554/eLife.92938 -
Cerebral Cortex (New York, N.Y. : 1991) Jun 2024Nonpainful tactile sensory stimuli are processed in the cortex, subcortex, and brainstem. Recent functional magnetic resonance imaging studies have highlighted the value...
Nonpainful tactile sensory stimuli are processed in the cortex, subcortex, and brainstem. Recent functional magnetic resonance imaging studies have highlighted the value of whole-brain, systems-level investigation for examining sensory processing. However, whole-brain functional magnetic resonance imaging studies are uncommon, in part due to challenges with signal to noise when studying the brainstem. Furthermore, differentiation of small sensory brainstem structures such as the cuneate and gracile nuclei necessitates high-resolution imaging. To address this gap in systems-level sensory investigation, we employed a whole-brain, multi-echo functional magnetic resonance imaging acquisition at 3T with multi-echo independent component analysis denoising and brainstem-specific modeling to enable detection of activation across the entire sensory system. In healthy participants, we examined patterns of activity in response to nonpainful brushing of the right hand, left hand, and right foot (n = 10 per location), and found the expected lateralization, with distinct cortical and subcortical responses for upper and lower limb stimulation. At the brainstem level, we differentiated the adjacent cuneate and gracile nuclei, corresponding to hand and foot stimulation respectively. Our findings demonstrate that simultaneous cortical, subcortical, and brainstem mapping at 3T could be a key tool to understand the sensory system in both healthy individuals and clinical cohorts with sensory deficits.
Topics: Humans; Brain Stem; Female; Male; Magnetic Resonance Imaging; Adult; Brain Mapping; Young Adult; Cerebral Cortex; Touch Perception; Physical Stimulation; Hand
PubMed: 38940832
DOI: 10.1093/cercor/bhae273 -
Journal of Integrative Neuroscience Jun 2024Neurofeedback is a non-invasive brain training technique used to enhance and treat hyperactivity disorder by altering the patterns of brain activity. Nonetheless, the...
BACKGROUND
Neurofeedback is a non-invasive brain training technique used to enhance and treat hyperactivity disorder by altering the patterns of brain activity. Nonetheless, the extent of enhancement by neurofeedback varies among individuals/patients and many of them are irresponsive to this treatment technique. Therefore, several studies have been conducted to predict the effectiveness of neurofeedback training including the theta/beta protocol with a specific emphasize on slow cortical potential (SCP) before initiating treatment, as well as examining SCP criteria according to age and sex criteria in diverse populations. While some of these studies failed to make accurate predictions, others have demonstrated low success rates. This study explores functional connections within various brain lobes across different frequency bands of electroencephalogram (EEG) signals and the value of phase locking is used to predict the potential effectiveness of neurofeedback treatment before its initiation.
METHODS
This study utilized EEG data from the Mendelian database. In this database, EEG signals were recorded during neurofeedback sessions involving 60 hyperactive students aged 7-14 years, irrespective of sex. These students were categorized into treatable and non-treatable. The proposed method includes a five-step algorithm. Initially, the data underwent preprocessing to reduce noise using a multi-stage filtering process. The second step involved extracting alpha and beta frequency bands from the preprocessed EEG signals, with a particular emphasis on the EEG recorded from sessions 10 to 20 of neurofeedback therapy. In the third step, the method assessed the disparity in brain signals between the two groups by evaluating functional relationships in different brain lobes using the phase lock value, a crucial data characteristic. The fourth step focused on reducing the feature space and identifying the most effective and optimal electrodes for neurofeedback treatment. Two methods, the probability index (-value) via a -test and the genetic algorithm, were employed. These methods showed that the optimal electrodes were in the frontal lobe and central cerebral cortex, notably channels C3, FZ, F4, CZ, C4, and F3, as they exhibited significant differences between the two groups. Finally, in the fifth step, machine learning classifiers were applied, and the results were combined to generate treatable and non-treatable labels for each dataset.
RESULTS
Among the classifiers, the support vector machine and the boosting method demonstrated the highest accuracy when combined. Consequently, the proposed algorithm successfully predicted the treatability of individuals with hyperactivity in a short time and with limited data, achieving an accuracy of 90.6% in the neurofeedback method. Additionally, it effectively identified key electrodes in neurofeedback treatment, reducing their number from 32 to 6.
CONCLUSIONS
This study introduces an algorithm with a 90.6% accuracy for predicting neurofeedback treatment outcomes in hyperactivity disorder, significantly enhancing treatment efficiency by identifying optimal electrodes and reducing their number from 32 to 6. The proposed method enables the prediction of patient responsiveness to neurofeedback therapy without the need for numerous sessions, thus conserving time and financial resources.
Topics: Humans; Neurofeedback; Attention Deficit Disorder with Hyperactivity; Adolescent; Male; Female; Child; Electroencephalography; Cerebral Cortex; Brain Waves; Treatment Outcome
PubMed: 38940096
DOI: 10.31083/j.jin2306121 -
Journal of Integrative Neuroscience May 2024In this study, we used electroencephalogram (EEG) to investigate the activity pattern of the cerebral cortex related to visual pursuit and saccade strategies to predict...
BACKGROUND
In this study, we used electroencephalogram (EEG) to investigate the activity pattern of the cerebral cortex related to visual pursuit and saccade strategies to predict the arrival position of a visual target. In addition, we clarified the differences in the EEG of those who could predict the arrival position well using the saccade strategy compared to those who were not proficient.
METHODS
Sixteen participants performed two tasks: the "Pursuit Strategy Task (PST)" and the "Saccade Strategy Task (SST)" while undergoing EEG. For the PST, the participants were instructed to follow the target with their eyes throughout its trajectory and indicate when it reached the final point. For the SST, the participants were instructed to shift their gaze to the end point of arrival once they had predicted it.
RESULTS
Low beta EEG activity at the Oz, Cz, and CP2 electrodes was significantly higher during the SST than during the PST. In addition, low beta EEG activity at P7 electrode was significantly higher in the group showing a small position error (PE) than in the group showing a large PE at response.
CONCLUSIONS
EEG activity at the Oz, Cz, and CP2 electrodes during the SST may reflect visuospatial attention to the moving target, the tracking of moving targets, and the focus on the final destination position. In addition, EEG activity at P7 electrode may more accurately detect the speed and direction of the moving target by the small PE group at response.
Topics: Humans; Saccades; Male; Female; Young Adult; Electroencephalography; Adult; Cerebral Cortex; Attention; Pursuit, Smooth; Visual Perception; Psychomotor Performance; Space Perception
PubMed: 38940093
DOI: 10.31083/j.jin2306108 -
Journal of Integrative Neuroscience Jun 2024root, cataloged as "" in the Korean Pharmacopeia, is rich in various anthraquinones known for their anti-inflammatory and antioxidant properties. Formulations...
BACKGROUND
root, cataloged as "" in the Korean Pharmacopeia, is rich in various anthraquinones known for their anti-inflammatory and antioxidant properties. Formulations containing are traditionally employed for treating neurological conditions. This study aimed to substantiate the antiepileptic and neuroprotective efficacy of root extract (RTE) against trimethyltin (TMT)-induced epileptic seizures and hippocampal neurodegeneration.
METHODS
The constituents of RTE were identified by ultra-performance liquid chromatography (UPLC). Experimental animals were grouped into the following five categories: control, TMT, and three TMT+RTE groups with dosages of 10, 30, and 100 mg/kg. Seizure severity was assessed daily for comparison between the groups. Brain tissue samples were examined to determine the extent of neurodegeneration and neuroinflammation using histological and molecular biology techniques. Network pharmacology analysis involved extracting herbal targets for and disease targets for epilepsy from multiple databases. A protein-protein interaction network was built using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and pivotal targets were determined by topological analysis. Enrichment analysis was performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool to elucidate the underlying mechanisms.
RESULTS
The RTE formulation was found to contain sennoside A, sennoside B, chrysophanol, emodin, physcion, (+)-catechin, and quercetin-3-O-glucuronoid. RTE effectively inhibited TMT-induced seizures at 10, 30, and 100 mg/kg dosages and attenuated hippocampal neuronal decay and neuroinflammation at 30 and 100 mg/kg dosages. Furthermore, RTE significantly reduced mRNA levels of tumor necrosis factor (), glial fibrillary acidic protein (), and in hippocampal tissues. Network analysis revealed TNF, Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), Protein c-fos (FOS), RAC-alpha serine/threonine-protein kinase (AKT1), and Mammalian target of rapamycin (mTOR) as the core targets. Enrichment analysis demonstrated significant involvement of components in neurodegeneration ( = 4.35 × 10-5) and TNF signaling pathway ( = 9.94 × 10-5).
CONCLUSIONS
The and analyses performed in this study suggests that RTE can potentially modulate TMT-induced epileptic seizures and neurodegeneration. Therefore, root is a promising herbal treatment option for antiepileptic and neuroprotective applications.
Topics: Animals; Neuroprotective Agents; Trimethyltin Compounds; Plant Extracts; Rheum; Plant Roots; Male; Anticonvulsants; Epilepsy; Hippocampus; Disease Models, Animal; Neurodegenerative Diseases; Computer Simulation; Network Pharmacology; Protein Interaction Maps; Rats
PubMed: 38940090
DOI: 10.31083/j.jin2306122 -
Journal of Integrative Neuroscience Jun 2024The effects of heat acclimation (HA) on the hypothalamus after exertional heatstroke (EHS) and the specific mechanism have not been fully elucidated, and this study...
BACKGROUND
The effects of heat acclimation (HA) on the hypothalamus after exertional heatstroke (EHS) and the specific mechanism have not been fully elucidated, and this study aimed to address these questions.
METHODS
In the present study, rats were randomly assigned to the control, EHS, HA, or HA + EHS groups (n = 9). Hematoxylin and eosin (H&E) staining was used to examine pathology. Tandem mass tag (TMT)-based proteomic analysis was utilized to explore the impact of HA on the protein expression profile of the hypothalamus after EHS. Bioinformatics analysis was used to predict the functions of the differentially expressed proteins. The differential proteins were validated by western blotting. An enzyme-linked immunosorbent assay was used to measure the expression levels of inflammatory cytokines in the serum.
RESULTS
The H&E staining (n = 5) results revealed that there were less structural changes in hypothalamus in the HA + EHS group compared with the EHS group. Proteomic analysis (n = 4) revealed that proinflammatory proteins such as argininosuccinate synthetase (ASS1), high mobility group protein B2 (HMGB2) and vimentin were evidently downregulated in the HA + EHS group. The levels of interleukin (IL)-1β, IL-1, and IL-8 were decreased in the serum samples (n = 3) from HA + EHS rats.
CONCLUSIONS
HA may alleviate hypothalamic damage caused by heat attack by inhibiting inflammatory activities, and ASS1, HMGB2 and vimentin could be candidate factors involved in the exact mechanism.
Topics: Animals; Hypothalamus; Heat Stroke; Rats; Proteomics; Male; Rats, Sprague-Dawley; Physical Exertion; Disease Models, Animal
PubMed: 38940089
DOI: 10.31083/j.jin2306116