Brain homeostasis run amok

This chapter elucidates how normal homeostatic brain mechanisms may run amok and how this process explains the presently unexplained symptoms of long-COVID syndrome. It describes how reorganizations in brain connectivity, referred to as neuroplasticity, provide us with a framework for the brain independently perpetuating symptoms such as fatigue, pain, cognitive problems, sleep disturbances, and headaches in the absence of peripheral organ damage, and reviews supporting studies done in chronic fatigue syndrome/Myalgic encephalomyelitis and fibromyalgia. The chapter provides evidence from recent reports that such neuroplasticity is associated with the persistent symptoms of long-COVID syndrome. The brain's automatic responses, those not engaged in consciousness, work via the autonomic nervous system, which controls breathing, heart rate, blood pressure, hormone secretions, and bowel functions, among other things. The human nervous system consists of many, highly interconnected circuits or networks that control everything the body does, from simple reflexes to higher order thinking, and everything in between. © 2023 John Wiley & Sons Ltd. All rights reserved.

Effects of hyperbaric oxygen therapy on functional and structural connectivity in post-COVID-19 condition patients: A randomized, sham-controlled trial.

INTRODUCTION: Post-COVID-19 condition refers to a range of persisting physical, neurocognitive, and neuropsychological symptoms after SARS-CoV-2 infection. Abnormalities in brain connectivity were found in recovered patients compared to non-infected controls. This study aims to evaluate the effect of hyperbaric oxygen therapy (HBOT) on brain connectivity in post-COVID-19 patients. METHODS: In this randomized, sham-controlled, double-blind trial, 73 patients were randomized to receive 40 daily sessions of HBOT (n = 37) or sham treatment (n = 36). We examined pre- and post-treatment resting-state brain functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) scans to evaluate functional and structural connectivity changes, which were correlated to cognitive and psychological distress measures. RESULTS: The ROI-to-ROI analysis revealed decreased internetwork connectivity in the HBOT group which was negatively correlated to improvements in attention and executive function scores (p < 0.001). Significant group-by-time interactions were demonstrated in the right hippocampal resting state function connectivity (rsFC) in the medial prefrontal cortex (PFWE = 0.002). Seed-to-voxel analysis also revealed a negative correlation in the brief symptom inventory (BSI-18) score and in the rsFC between the amygdala seed, the angular gyrus, and the primary sensory motor area (PFWE = 0.012, 0.002). Positive correlations were found between the BSI-18 score and the left insular cortex seed and FPN (angular gyrus) (PFWE < 0.0001). Tractography based structural connectivity analysis showed a significant group-by-time interaction in the fractional anisotropy (FA) of left amygdala tracts (F = 7.81, P = 0.007). The efficacy measure had significant group-by-time interactions (F = 5.98, p = 0.017) in the amygdala circuit. CONCLUSIONS: This study indicates that HBOT improves disruptions in white matter tracts and alters the functional connectivity organization of neural pathways attributed to cognitive and emotional recovery in post-COVID-19 patients. This study also highlights the potential of structural and functional connectivity analysis as a promising treatment response monitoring tool.

Connectivity and innovation activities in global cities: Local, global, and infrastructural perspectives

In this dissertation, I evaluate questions related to the role of connectivity in economic and innovation-related processes. Specifically, I utilize conceptual frameworks from the economic geography literature to study the relevance of internal, external, and infrastructural connectivity at a city level.In the first essay, I examine the role of intra-metropolitan connectivity of inventors and evaluate the quality of the associated innovation outputs. I focus on the fact that there exist meaningful demographic differences between people domiciled in city centers and the suburban areas and claim that these heterogeneities serve as sources of diversity and creativity. I suggest empirical evidence that the collaboration of inventors from the two different sub-regions is associated with higher quality innovation outcomes. I further study how firm heterogeneity moderates the effects of this intra-metropolitan connectivity. The findings suggest that local firms and small to mid-sized firms (SMEs) enjoy more benefits because foreign firms and large firms are exploiting their own global network. This paper provides both managerial and practical implications that a metropolitan area may improve its quality of innovation outputs by taking advantage of the urban-suburban connectivity among the inventors. In the second essay, I provide specific guidelines to city planners to evaluate the external connectivity of the associated city. Cities are industry hotspots, playing vital roles as centers of economic development. Each city has different location-specific advantages that can foster different core industries and firms, participating in diverse activities within a global value chain system. Given the increasing rate of globalization at the metro level, it has become paramount for cities to establish and develop economic partnerships with other cities to further growing their regional economies. However, few city planners have clear directions in choosing partner cities, and the decisions are rarely based on appropriate data analysis. Based on the Brookings Institution's Global City Initiative 2.0 project, and after enhancing it with additional data analyses, I introduce a set of step-by-step guidelines to city planners for finding global partner cities. To provide an actual case, I share our own anecdote regarding how Philadelphia chose potential partner cities in order to attract more FDI in its biopharmaceutical sector and foster innovation activities. I also present evidence that the inadequate ability of local firms to source knowledge from international markets associates with relatively weak economic performance. The comprehensive analyses of the city's role in the global value chain include from the upstream (Research and Development) and the midstream (FDI, imports, international joint ventures) to the downstream (exports). This case-based paper provides practical implications to city planners by providing ways of understanding the broad global value chain with which the city is involved.In the third essay, I assess the relationship between soft networks and hard networks of global cities. Public transportation systems (PTS) have been developed along with the associated metropolitan area. Scholars in urban studies have emphasized the important roles of PTS in connecting diverse people, regions, activities, and socio-economic consequences. In this paper, I examine the relationship between public transportation systems and the innovation network in four major U.S. cities in the northeast - New York, Boston, Philadelphia, and Pittsburgh. I graphically show that inventor locations, as well as their connectivity, are established along with the city's public transportation networks. I further stipulate that this relationship has been seriously undermined by the recent pandemic - COVID-19. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

Olfactory loss and brain connectivity after COVID-19.

To address the impact of COVID-19 olfactory loss on the brain, we analyzed the neural connectivity of the central olfactory system in recently SARS-CoV-2 infected subjects with persisting olfactory impairment (hyposmia). Twenty-seven previously SARS-CoV-2 infected subjects (10 males, mean age ± SD 40.0 ± 7.6 years) with clinically confirmed COVID-19 related hyposmia, and eighteen healthy, never SARS-CoV-2 infected, normosmic subjects (6 males, mean age ± SD 36.0 ± 7.1 years), were recruited in a 3 Tesla MRI study including high angular resolution diffusion and resting-state functional MRI acquisitions. Specialized metrics of structural and functional connectivity were derived from a standard parcellation of olfactory brain areas and a previously validated graph-theoretic model of the human olfactory functional network. These metrics were compared between groups and correlated to a clinical index of olfactory impairment. On the scanning day, all subjects were virus-free and cognitively unimpaired. Compared to control, both structural and functional connectivity metrics were found significantly increased in previously SARS-CoV-2 infected subjects. Greater residual olfactory impairment was associated with more segregated processing within regions more functionally connected to the anterior piriform cortex. An increased neural connectivity within the olfactory cortex was associated with a recent SARS-CoV-2 infection when the olfactory loss was a residual COVID-19 symptom. The functional connectivity of the anterior piriform cortex, the largest cortical recipient of afferent fibers from the olfactory bulb, accounted for the inter-individual variability in the sensory impairment. Albeit preliminary, these findings could feature a characteristic brain connectivity response in the presence of COVID-19 related residual hyposmia.

Effect of a Brain-Computer Interface Based on Pedaling Motor Imagery on Cortical Excitability and Connectivity.

Recently, studies on cycling-based brain-computer interfaces (BCIs) have been standing out due to their potential for lower-limb recovery. In this scenario, the behaviors of the sensory motor rhythms and the brain connectivity present themselves as sources of information that can contribute to interpreting the cortical effect of these technologies. This study aims to analyze how sensory motor rhythms and cortical connectivity behave when volunteers command reactive motor imagery (MI) BCI that provides passive pedaling feedback. We studied 8 healthy subjects who performed pedaling MI to command an electroencephalography (EEG)-based BCI with a motorized pedal to receive passive movements as feedback. The EEG data were analyzed under the following four conditions: resting, MI calibration, MI online, and receiving passive pedaling (on-line phase). Most subjects produced, over the foot area, significant event-related desynchronization (ERD) patterns around Cz when performing MI and receiving passive pedaling. The sharpest decrease was found for the low beta band. The connectivity results revealed an exchange of information between the supplementary motor area (SMA) and parietal regions during MI and passive pedaling. Our findings point to the primary motor cortex activation for most participants and the connectivity between SMA and parietal regions during pedaling MI and passive pedaling.