Structural-functional connectivity mapping of the insular cortex system: A combined data-driven and meta-analytic topic mapping approach

The insular cortex is an important anatomical integration hub and can serve as a suitable model for exploring structural-functional relationships. In this study, we examined structural and functional magnetic resonance correspondence via the diffusion tensor imaging (DTI) and resting-state functional connectivity (RSFC) profiles of the insular cortex and its mapping with functional networks (FNs) across the brain. We explored these associations primarily by using a data-driven method to independently estimate the structural-functional connectivity in the human insular cortex system. Data were obtained from the Human Connectome Project comprising 108 resting-state functional magnetic resonance neuroimaging (fMRI) and DTI. Brain networks were acquired and defined according to the seven Yeo FNs. In general, we observed moderate to high association between the structural and functional mapping results of three distinct insular subregions: the posterior insula (sensorimotor: RSFC, DTI = 50%, 72%, respectively), dorsal anterior insula (ventral attention: RSFC, DTI = 83%, 83%, respectively), and ventral anterior insula (frontoparietal: RSFC, DTI = 42%, 89%, respectively). We also examined the cognitive and behavioral domains associated with these three insular subregions using meta-analytic topic mapping and found cognitive and behavioral relations to affective processes, reflecting the core properties of the cytoarchitecture. In sum, given the core role of the insula in the human brain, our findings on the correspondence of the insular cortex system between DTI and RSFC mappings provide a novel approach and insight for clinical researchers to detect dysfunctional brain organization in various neurological disorders.

Loss of Calretinin in L5a impairs the formation of the barrel cortex leading to abnormal whisker-mediated behaviors

The rodent whisker-barrel cortex system has been established as an ideal model for studying sensory information integration. The barrel cortex consists of barrel and septa columns that receive information input from the lemniscal and paralemniscal pathways, respectively. Layer 5a is involved in both barrel and septa circuits and play a key role in information integration. However, the role of layer 5a in the development of the barrel cortex remains unclear. Previously, we found that calretinin is dynamically expressed in layer 5a. In this study, we analyzed calretinin KO mice and found that the dendritic complexity and length of layer 5a pyramidal neurons were significantly decreased after calretinin ablation. The membrane excitability and excitatory synaptic transmission of layer 5a neurons were increased. Consequently, the organization of the barrels was impaired. Moreover, layer 4 spiny stellate cells were not able to properly gather, leading to abnormal formation of barrel walls as the ratio of barrel/septum size obviously decreased. Calretinin KO mice exhibited deficits in exploratory and whisker-associated tactile behaviors as well as social novelty preference. Our study expands our knowledge of layer 5a pyramidal neurons in the formation of barrel walls and deepens the understanding of the development of the whisker-barrel cortex system.

Loss of Calretinin in L5a Impairs the Formation of the Barrel Cortex Leading to Abnormal Behaviors

The rodent whisker-barrel cortex system has been established as an ideal model for studying sensory information integration. The barrel cortex consists of barrel and septa columns that receive information input from the lemniscal and paralemniscal pathways, respectively. L5a is involved in both barrel and septa circuits and play a key role in information integration. However, the role of L5a in the development of the barrel cortex remains unclear. Previously, we found that Calretinin is dynamically expressed in L5a. In this study, we analyzed Cr KO mice and found that the dendritic complexity and length of L5a pyramidal neurons were significantly decreased after Cr ablation. The membrane excitability and excitatory synaptic transmission of L5a neurons were increased. Consequently, the organization of the barrels was impaired. Moreover, L4 spiny stellate cells were not able to properly gather, leading to abnormal formation of barrel walls as the ratio of barrel/septum size obviously decreased. Cr KO mice exhibited deficits in exploratory and whisker-associated tactile behaviors as well as social novelty preference. Our study expands our knowledge of L5a pyramidal neurons in the formation of barrel walls and deepens the understanding of the development of the whisker-barrel cortex system.

C3D data based on 2-dimensional images from video camera

The Human three-dimensional (3D) musculoskeletal model is based on motion analysis methods and can be obtained by particular motion capture systems that export 3D data with coordinate 3D (C3D) format. Unique cameras and specific software are essential for analyzing the data. This equipment is quite expensive, and using them is time-consuming. This research intends to use ordinary video cameras and open source systems to get 3D data and create a C3D format due to these problems. By capturing movements with two video cameras, marker coordination is obtainable using Skill-Spector. To create C3D data from 3D coordinates of the body points, MATLAB functions were used. The subject was captured simultaneously with both the Cortex system and two video cameras during each validation test. The mean correlation coefficient of datasets is 0.7. This method can be used as an alternative method for motion analysis due to a more detailed comparison. The C3D data collection, which we presented in this research, is more accessible and cost-efficient than other systems. In this method, only two cameras have been used.

Parallel Neural Multiprocessing with Gamma Frequency Latencies

The Poisson variability in cortical neural responses has been typically modeled using spike averaging techniques, such as trial averaging and rate coding, since such methods can produce reliable correlates of behavior. However, mechanisms that rely on counting spikes could be slow and inefficient and thus might not be useful in the brain for computations at timescales in the 10 millisecond range. This issue has motivated a search for alternative spike codes that take advantage of spike timing and has resulted in many studies that use synchronized neural networks for communication. Here we focus on recent studies that suggest that the gamma frequency may provide a reference that allows local spike phase representations that could result in much faster information transmission. We have developed a unified model (gamma spike multiplexing) that takes advantage of a single cycle of a cell's somatic gamma frequency to modulate the generation of its action potentials. An important consequence of this coding mechanism is that it allows multiple independent neural processes to run in parallel, thereby greatly increasing the processing capability of the cortex. System-level simulations and preliminary analysis of mouse cortical cell data are presented as support for the proposed theoretical model.

Anorexia, a First Sign of Diagnosis in Severe Pediatric Disorders

Anorexia, as a symptom, is part of the complex picture of a large pediatric pathology. Through attentive observation, anorexia as a single sign, may announce the onset of serious and particular affections. In all 4 cases, anorexia was a singular sign for a period of time before the complete illness was established. Whether adenoid cyst, cerebral abscess, pontocerebellar atrophy, Wilms tumor, neuroendocrine system of hunger regulation, satiety, complex control achieved through interactions of the limbic-hypothalamus-cortex system, come into operation with the occurrence of organic anorexia, different of the psychogenic anorexia (usually common in adolescents). The study is an alarm signal on the importance of a symptom in early diagnosis, and the rapid establishment of therapy in severe life threatening conditions.