An Electroencephalographic Analysis of the Functional Development of the Cortical Regions of the Brain in Children during the First Month of Life

1984 ◽  
Vol 22 (3) ◽  
pp. 47-60
Author(s):  
I. N. Posikera ◽  
T. A. Stroganova
Keyword(s):  
Functional Development ◽  
Cortical Regions ◽  
The Brain

scholarly journals Physical positioning markedly enhances brain transduction after intrathecal AAV9 infusion

2018 ◽  
Vol 4 (11) ◽  
pp. eaau9859 ◽  
Author(s):  
Michael J. Castle ◽  
Yuhsiang Cheng ◽  
Aravind Asokan ◽  
Mark H. Tuszynski
Keyword(s):  
Gene Expression ◽  
Gene Delivery ◽  
Neurological Disorders ◽  
Fold Increase ◽  
Brain Regions ◽  
Intrathecal Administration ◽  
Simple Method ◽  
Virus Serotype ◽  
Cortical Regions ◽  
The Brain

Several neurological disorders may benefit from gene therapy. However, even when using the lead vector candidate for intrathecal administration, adeno-associated virus serotype 9 (AAV9), the strength and distribution of gene transfer to the brain are inconsistent. On the basis of preliminary observations that standard intrathecal AAV9 infusions predominantly drive reporter gene expression in brain regions where gravity might cause cerebrospinal fluid to settle, we tested the hypothesis that counteracting vector “settling” through animal positioning would enhance vector delivery to the brain. When rats are either inverted in the Trendelenburg position or continuously rotated after intrathecal AAV9 infusion, we find (i) a significant 15-fold increase in the number of transduced neurons, (ii) a marked increase in gene delivery to cortical regions, and (iii) superior animal-to-animal consistency of gene expression. Entorhinal, prefrontal, frontal, parietal, hippocampal, limbic, and basal forebrain neurons are extensively transduced: 95% of transduced cells are neurons, and greater than 70% are excitatory. These findings provide a novel and simple method for broad gene delivery to the cortex and are of substantial relevance to translational programs for neurological disorders, including Alzheimer’s disease and related dementias, stroke, and traumatic brain injury.

scholarly journals Scale-Free Coupled Dynamics in Brain Networks Captured by Bivariate Focus-Based Multifractal Analysis

2021 ◽  
Vol 11 ◽  
Author(s):  
Orestis Stylianou ◽  
Frigyes Samuel Racz ◽  
Andras Eke ◽  
Peter Mukli
Keyword(s):  
Resting State ◽  
Functional Coupling ◽  
Dependent Manner ◽  
Coupled Dynamics ◽  
Scale Free ◽  
Neural Processes ◽  
Eeg Recordings ◽  
Cortical Regions ◽  
The Brain

While most connectivity studies investigate functional connectivity (FC) in a scale-dependent manner, coupled neural processes may also exhibit broadband dynamics, manifesting as power-law scaling of their measures of interdependence. Here we introduce the bivariate focus-based multifractal (BFMF) analysis as a robust tool for capturing such scale-free relations and use resting-state electroencephalography (EEG) recordings of 12 subjects to demonstrate its performance in reconstructing physiological networks. BFMF was employed to characterize broadband FC between 62 cortical regions in a pairwise manner, with all investigated connections being tested for true bivariate multifractality. EEG channels were also grouped to represent the activity of six resting-state networks (RSNs) in the brain, thus allowing for the analysis of within- and between- RSNs connectivity, separately. Most connections featured true bivariate multifractality, which could be attributed to the genuine scale-free coupling of neural dynamics. Bivariate multifractality showed a characteristic topology over the cortex that was highly concordant among subjects. Long-term autocorrelation was higher in within-RSNs, while the degree of multifractality was generally found stronger in between-RSNs connections. These results offer statistical evidence of the bivariate multifractal nature of functional coupling in the brain and validate BFMF as a robust method to capture such scale-independent coupled dynamics.

scholarly journals Distributed context-dependent choice information in mouse dorsal-parietal cortex

2021 ◽  
Author(s):  
Javier Orlandi ◽  
Mohammad Adbolrahmani ◽  
Ryo Aoki ◽  
Dmitry Lyamzin ◽  
Andrea Benucci
Keyword(s):  
Decision Making ◽  
Decision Variable ◽  
Visual Stream ◽  
Posterior Cortex ◽  
Neural Data ◽  
Context Dependent ◽  
Cortical Regions ◽  
Low Dimensional ◽  
Independent Decision ◽  
The Brain

Abstract Choice information appears in the brain as distributed signals with top-down and bottom-up components that together support decision-making computations. In sensory and associative cortical regions, the presence of choice signals, their strength, and area specificity are known to be elusive and changeable, limiting a cohesive understanding of their computational significance. In this study, examining the mesoscale activity in mouse posterior cortex during a complex visual discrimination task, we found that broadly distributed choice signals defined a decision variable in a low-dimensional embedding space of multi-area activations, particularly along the ventral visual stream. The subspace they defined was near-orthogonal to concurrently represented sensory and motor-related activations, and it was modulated by task difficulty and contextually by the animals’ attention state. To mechanistically relate choice representations to decision-making computations, we trained recurrent neural networks with the animals’ choices and found an equivalent decision variable whose context-dependent dynamics agreed with that of the neural data. In conclusion, our results demonstrated an independent decision variable broadly represented in the posterior cortex, controlled by task features and cognitive demands. Its dynamics reflected decision computations, possibly linked to context-dependent feedback signals used for probabilistic-inference computations in variable animal-environment interactions.

scholarly journals Investigation of Delayed Response during Real-Time Cursor Control Using Electroencephalography

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Hyeonseok Kim ◽  
Natsue Yoshimura ◽  
Yasuharu Koike
Keyword(s):  
Real Time ◽  
High Accuracy ◽  
Delayed Response ◽  
Cursor Control ◽  
Parietal Lobes ◽  
Delay Times ◽  
Cortical Regions ◽  
Occipital Lobes ◽  
Response Classification ◽  
The Brain

Error-related brain activation has been investigated for advanced brain-machine interfaces (BMI). However, how a delayed response of cursor control in BMI systems should be handled is not clear. Therefore, the purpose of this study was to investigate how participants responded to delayed cursor control. Six subjects participated in the experiment and performed a wrist-bending task. For three distinct delay intervals (an interval where participants could not perceive the delay, an interval where participants could not be sure whether there was a delay or not, and an interval where participants could perceive the delay), we assessed two types of binary classifications (“Yes + No” vs. “I don’t know” and “Yes” vs. “No”) based on participants’ responses and applied delay times (thus, four types of classification, overall). For most participants, the “Yes vs. No” classification had higher accuracy than “Yes + No” vs. “I don’t know” classification. For the “Yes + No” vs. “I don’t know” classification, most participants displayed higher accuracy based on response classification than delay classification. Our results demonstrate that a class only for “I don’t know” largely contributed to these differences. Many independent components (ICs) that exhibited high accuracy in “Yes + No” vs. “I don’t know” response classification were associated with activation of areas from the frontal to parietal lobes, while many ICs that showed high accuracy in the “Yes vs. No” classification were associated with activation of an area ranging from the parietal to the occipital lobes and were more broadly localized in cortical regions than was seen for the “Yes + No” vs. “I don’t know” classification. Our results suggest that small and large delays in real-time cursor control differ not only in the magnitude of the delay but should be handled as distinct information in different ways and might involve differential processing in the brain.

Oxidative damage to DNA in plaques of MS brains

1998 ◽  
Vol 4 (5) ◽  
pp. 413-418 ◽  
Author(s):  
Olga Vladimirova ◽  
John O'Connor ◽  
Alan Cahill ◽  
Hansjuerg Alder ◽  
Catalin Butunoi ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Degenerative Process ◽  
Oxidative Markers ◽  
Normal Appearing White Matter ◽  
The Central Nervous System ◽  
Cortical Regions ◽  
Tissue Alterations ◽  
Oxidative Damage To Dna ◽  
The Brain ◽  
Cerebellar Symptoms

A major cause of clinical disability in multiple sclerosis (MS) is related to a degenerative process in the central nervous system (CNS) which ultimately develops from a potentially reversible inflammation and demyelination. The mechanism of this degenerative process within MS lesions is not completely understood. We hypothesize that oxidative damage to DNA secondary to inflammation may contribute to irreversible tissue alterations in a plaque. To test this assumption, we determined the level of a DNA oxidative marker, 8-hydroxy-deoxy-guanosine (8-OH-dG) in the normal appearing white matter (NAWM), plaque and cortical regions of cerebella from MS patients who suffered from severe cerebellar symptoms during the course of the disease, and in NAWM and cortical regions of cerebella from non-neurological controls. We found a significant increase in DNA oxidation within plaques compared to NAWM specimens in MS cerebella. A tendency for increase of oxidative markers in normal appearing cortical tissues located in the proximity of MS plaques was also observed when compared to those in control cortical specimens. Oxidative damage to DNA in MS lesions, and in neuron rich areas located in the proximity of these lesions is likely related to the release of reactive oxygen species (ROS) and nitric oxide (NO) during inflammation in the brain. This biochemical impairment of DNA and of other macromolecules may contribute to the development of severe clinical disability through the induction of degenerative changes within and outside of plaques in MS brains.

scholarly journals Facephenes and rainbows: Causal evidence for functional and anatomical specificity of face and color processing in the human brain

2017 ◽  
Vol 114 (46) ◽  
pp. 12285-12290 ◽  
Author(s):  
Gerwin Schalk ◽  
Christoph Kapeller ◽  
Christoph Guger ◽  
Hiroshi Ogawa ◽  
Satoru Hiroshima ◽  
...  
Keyword(s):  
Human Brain ◽  
Mental Process ◽  
Color Processing ◽  
Face Area ◽  
Neurosurgical Patient ◽  
Patient Reported ◽  
Stimulus Classes ◽  
Cortical Regions ◽  
The Brain

Neuroscientists have long debated whether some regions of the human brain are exclusively engaged in a single specific mental process. Consistent with this view, fMRI has revealed cortical regions that respond selectively to certain stimulus classes such as faces. However, results from multivoxel pattern analyses (MVPA) challenge this view by demonstrating that category-selective regions often contain information about “nonpreferred” stimulus dimensions. But is this nonpreferred information causally relevant to behavior? Here we report a rare opportunity to test this question in a neurosurgical patient implanted for clinical reasons with strips of electrodes along his fusiform gyri. Broadband gamma electrocorticographic responses in multiple adjacent electrodes showed strong selectivity for faces in a region corresponding to the fusiform face area (FFA), and preferential responses to color in a nearby site, replicating earlier reports. To test the causal role of these regions in the perception of nonpreferred dimensions, we then electrically stimulated individual sites while the patient viewed various objects. When stimulated in the FFA, the patient reported seeing an illusory face (or “facephene”), independent of the object viewed. Similarly, stimulation of color-preferring sites produced illusory “rainbows.” Crucially, the patient reported no change in the object viewed, apart from the facephenes and rainbows apparently superimposed on them. The functional and anatomical specificity of these effects indicate that some cortical regions are exclusively causally engaged in a single specific mental process, and prompt caution about the widespread assumption that any information scientists can decode from the brain is causally relevant to behavior.

Temporal Processing by Intrinsic Neural Network Dynamics

2016 ◽  
Vol 4 (4) ◽  
pp. 399-410 ◽  
Author(s):  
Elijah A. Petter ◽  
Hugo Merchant
Keyword(s):  
Temporal Processing ◽  
Temporal Dynamics ◽  
Brain Structures ◽  
Temporal Perception ◽  
Neural Network Dynamics ◽  
Central Clock ◽  
Cortical Regions ◽  
Local Circuits ◽  
The Brain

It is becoming more apparent that there are rich contributions to temporal processing across the brain. Temporal dynamics have been found from lower brain structures all the way to cortical regions. Specifically,in vitrocortical preparations have been extremely useful in understanding how local circuits can time. While many of these results depict vastly different processing than a traditional central clock metaphor they still leave questions as to how this information is integrated. We therefore review evidence to place the results pertaining to local circuit timers into the larger context of temporal perception and generalization.

Precocious ovarian stimulation following hypothalamic and amygdaloid lesions in rats

1960 ◽  
Vol 198 (2) ◽  
pp. 381-385 ◽  
Author(s):  
Mildred Elwers ◽  
Vaughn Critchlow
Keyword(s):  
Ovarian Stimulation ◽  
Histological Study ◽  
Amygdaloid Complex ◽  
Female Rats ◽  
Gonadotropin Secretion ◽  
Functional Development ◽  
Electrolytic Lesions ◽  
Basal Septum ◽  
The Brain ◽  
Hypothalamic Mechanism

The effects of neural lesions on the functional development of the reproductive system were studied in prepubertal female rats. Small electrolytic lesions were placed bilaterally in 66 female rats at 18–20 days of age; 42 littermates served as controls, and 7 rats were blank-operated. All animals were weighed two to three times a week and examined daily for vaginal opening. At 33 days of age the uteri, ovaries and adrenals were weighed and prepared for histological study. All brains were examined histologically for lesion localization. Lesions in the anterior hypothalamus or in the medial portion of the amygdaloid complex were associated with precocious ovarian stimulation. With the exception of one lesion in the basal septum and one in caudate-putamen, bilaterally symmetrical lesions in other parts of the brain and asymmetrical lesions have been ineffective. These results are compatible with an anterior hypothalamic mechanism involved in the inhibition of gonadotropin secretion and suggest the inclusion of the medial portion of the amygdaloid complex in this mechanism.

Changes in TMS Measures induced by repetitive TMS

2012 ◽  
Author(s):  
Joseph Classen ◽  
Katja Stefan
Keyword(s):  
Neural Plasticity ◽  
Therapeutic Potential ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Stimulus Frequency ◽  
Physiological Properties ◽  
Stimulation Period ◽  
Ischemic Nerve Block ◽  
Cortical Regions ◽  
The Brain ◽  
Insight Into

This article reviews several protocols of repetitive transcranial magnetic stimulation (rTMS)-induced plasticity. rTMS, when applied to the motor cortex or other cortical regions of the brain, may induce effects that outlast the stimulation period. The neural plasticity, which emerges as a result of such interventions, has been studied to gain insight into plasticity mechanisms of the brain. In two protocols the structure of rTMS trains is modified, informed by the knowledge of the physiological properties of the corticospinal system. Pulse configuration, stimulus frequency, stimulus intensity, the duration of the application period, and the total number of stimuli are some variables that have to be taken into account when reviewing the physiological effects of rTMS. This article also introduces the concept of patterned rTMS pulses and rTMS with ischemic nerve block. In addition, rTMS has raised considerable interest because of its therapeutic potential; however, much needs to be done in this field.

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