Lower Locus Coeruleus Integrity Signals Elevated Entorhinal Tau and Clinical Progression in Asymptomatic Older Individuals.

Objective: Elevated entorhinal cortex (EC) tau in low beta-amyloid individuals can predict accumulation of pathology and cognitive decline. We compared the accuracy of magnetic resonance imaging (MRI)-derived locus coeruleus integrity, neocortical beta-amyloid burden by positron emission tomography (PET), and hippocampal volume in identifying elevated entorhinal tau signal in asymptomatic individuals who are considered beta-amyloid PET-negative.

Methods: We included 188 asymptomatic individuals (70.

Effects of Low-Level Light Therapy on Resting-State Connectivity Following Moderate Traumatic Brain Injury: Secondary Analyses of a Double-blinded Placebo-controlled Study.

Background Low-level light therapy (LLLT) has been shown to modulate recovery in patients with traumatic brain injury (TBI). However, the impact of LLLT on the functional connectivity of the brain when at rest has not been well studied. Purpose To use functional MRI to assess the effect of LLLT on whole-brain resting-state functional connectivity (RSFC) in patients with moderate TBI at acute (within 1 week), subacute (2-3 weeks), and late-subacute (3 months) recovery phases.

Success Rate of Transcranial Doppler Scanning of Cerebral Arteries at Different Transtemporal Windows in Healthy Elderly Individuals.

This study measured the rates of success in applying transcranial Doppler (TCD) scanning at the middle, posterior and anterior temporal windows (MTW, PTW and ATW) in the elderly. A hand-held 1.6-MHz pulsed-wave TCD transducer was used to search for cerebral arteries at MTW, PTW and ATW locations.

Impaired Cerebrovascular Reactivity in Huntington's Disease.

There is increasing evidence that impairments of cerebrovascular function and/or abnormalities of the cerebral vasculature might contribute to early neuronal cell loss in Huntington's disease (HD). Studies in both healthy individuals as well as in patients with other neurodegenerative disorders have used an exogenous carbon dioxide (CO) challenge in conjunction with functional magnetic resonance imaging (fMRI) to assess regional cerebrovascular reactivity (CVR). In this study, we explored potential impairments of CVR in HD.

Persistent CO reactivity deficits are associated with neurological dysfunction up to one year after repetitive mild closed head injury in adolescent mice.

Cerebrovascular reactivity (CVR) deficits in adolescents with concussion may persist after resolution of neurological symptoms. Whether or not CVR deficits predict long term neurological function is unknown. We used adolescent mice closed head injury (CHI) models (54 g, 107 cm or 117 cm drop height), followed by blood oxygenation level dependent (BOLD)-functional MRI with CO challenge to assess CVR and brain connectivity.

Cerebrovascular Responses to O-CO Exchange Ratio under Brief Breath-Hold Challenge in Patients with Chronic Mild Traumatic Brain Injury.

Breath-by-breath oxygen-carbon dioxide (O-CO exchange ratio (bER) is a respiratory gas exchange (RGE) metric, which is the ratio of the changes in the partial pressure of O (ΔPO) to CO (ΔPCO) between end-inspiration and end-expiration, has been demonstrated to characterize the cerebrovascular responses to breath-hold challenge in healthy individuals. We aimed to explore whether bER could characterize cerebrovascular responses in patients with chronic mild traumatic brain injury (mTBI) under breath-hold challenge. We also investigated the correlation between bER and the severity of post-concussion symptoms.

Dynamic brain-body coupling of breath-by-breath O2-CO2 exchange ratio with resting state cerebral hemodynamic fluctuations.

Background: The origin of low frequency cerebral hemodynamic fluctuations (CHF) in the resting state remains unknown. Breath-by breath O2-CO2 exchange ratio (bER) has been reported to correlate with the cerebrovascular response to brief breath hold challenge at the frequency range of 0.008-0.

The role of carbon monoxide and heme oxygenase-1 in COVID-19.

• Low level carbon monoxide (CO) and heme oxygenase-1 (HO-1) may play a role on the effect of smoking on COVID-19. • CO and HO-1 are anti-inflammatory and cytoprotective and HO-1 is most protective if it is induced before the occurrence of an oxidative insult. • COVID-19 may by itself induce HO-1 and CO which may be potential markers of inflammation or cytokine storm.

Cerebrovascular reactivity assessment with O2-CO2 exchange ratio under brief breath hold challenge.

Background: Hypercapnia during breath holding is believed to be the dominant driver behind the modulation of cerebral blood flow (CBF). However, increasing evidence show that mild hypoxia and mild hypercapnia in breath hold (BH) could work synergistically to enhance CBF response. We hypothesized that breath-by-breath O2-CO2 exchange ratio (bER), defined as the ratio of the change in partial pressure of oxygen (ΔPO2) to that of carbon dioxide (ΔPCO2) between end inspiration and end expiration, would be able to better correlate with the global and regional cerebral hemodynamic responses (CHR) to BH challenge.

Cerebral vasomotor reactivity in reversible cerebral vasoconstriction syndrome.

Background Altered cerebrovascular tone is implicated in reversible cerebral vasoconstriction syndrome (RCVS). We evaluated vasomotor reactivity using bedside transcranial Doppler in RCVS patients. Methods In this retrospective case-control study, middle cerebral artery (MCA) blood flow velocities were compared at rest and in response to breath-hold in RCVS ( n = 8), Migraineurs ( n = 10), and non-headache Controls ( n = 10).

A case study of magnetic resonance imaging of cerebrovascular reactivity: a powerful imaging marker for mild traumatic brain injury.

Primary Objective: To use breath-hold functional magnetic resonance imaging (fMRI) to localize the brain regions with impaired cerebrovascular reactivity (CVR) in a female patient diagnosed with mild traumatic brain injury (mTBI). The extent of impaired CVR was evaluated 2 months after concussion. Follow-up scan was performed 1 year post-mTBI using the same breath-hold fMRI technique.

The challenge of connecting the dots in the B.R.A.I.N.

The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative has focused scientific attention on the necessary tools to understand the human brain and mind. Here, we outline our collective vision for what we can achieve within a decade with properly targeted efforts and discuss likely technological deliverables and neuroscience progress.

Neural encoding of acupuncture needling sensations: evidence from a FMRI study.

Deqi response, a psychophysical response characterized by a spectrum of different needling sensations, is essential for Chinese acupuncture clinical efficacy. Previous neuroimaging research works have investigated the neural correlates of an overall deqi response by summating the scores of different needling sensations. However, the roles of individual sensations in brain activity and how they interact with each other remain to be clarified.

Measurement of human brown adipose tissue volume and activity using anatomic MR imaging and functional MR imaging.

Unlabelled: The aim of this study was to assess the volume and function of human brown adipose tissue (BAT) in vivo using MR imaging.

Methods: BAT volumes under thermoneutral conditions in the cervical areas were assessed via water-fat contrast using the Dixon method and via water-saturation efficiency using fast spin-echo and T2-weighted images. The existence of cervical BAT was also assessed by (18)F-FDG PET/CT scans in the same subjects.

Analysis of maternal and fetal cardiovascular systems during hyperglycemic pregnancy in the nonobese diabetic mouse.

Preconception or gestationally induced diabetes increases morbidities and elevates long-term cardiovascular disease risks in women and their children. Spontaneously hyperglycemic (d)-NOD/ShiLtJ female mice, a type 1 diabetes model, develop bradycardia and hypotension after midpregnancy compared with normoglycemic, age- and gestational day (GD)-matched control (c-NOD) females. We hypothesized that onset of the placental circulation at GD 9-10 and rapid fetal growth from GD 14 correlate with aberrant hemodynamic outcomes in d-NOD females.

Does guasha offer hepatoprotective effect to chronic inactive hepatitis B carriers? A built-in design to control subject expectation.

Background: A previous case study showed that Guasha, an ancient manual therapeutic technique, could exert hepatoprotective effect in a human chronic active hepatitis B carrier (active-CHB) by modulating the liver enzymes, cytokines, and heme oxygenase-1 (HO-1). The present study serves as a control to the aforementioned case report. The controls were chronic inactive carriers (inactive-CHB) and noncarriers of hepatitis B (NCs).

Commonality and specificity of acupuncture action at three acupoints as evidenced by FMRI.

Previous work from our team and others has shown that manual acupuncture at LI4 (hegu), ST36 (zusanli), and LV3 (taichong) deactivates a limbic-paralimbic-neocortical brain network, and at the same time activates somatosensory regions of the brain. The objective of the present study was to explore the specificity and commonality of the brain response to manual acupuncture at LI4, ST36, and LV3, acupoints that are located on different meridians and are used to treat pain disorders. We used functional magnetic resonance imaging (fMRI) to monitor the brain responses to acupuncture at three different acupoints; we examined 46 healthy subjects who, according to their psychophysical responses, experienced deqi sensation during acupuncture.

Dynamic functional cerebral blood volume responses to normobaric hyperoxia in acute ischemic stroke.

Studies suggest that neuroprotective effects of normobaric oxygen (NBO) therapy in acute stroke are partly mediated by hemodynamic alterations. We investigated cerebral hemodynamic effects of repeated NBO exposures. Serial magnetic resonance imaging (MRI) was performed in Wistar rats subjected to focal ischemic stroke.

Anatomical and functional assessment of brown adipose tissue by magnetic resonance imaging.

Brown adipose tissue (BAT) is the primary tissue responsible for nonshivering thermogenesis in mammals. The amount of BAT and its level of activation help regulate the utilization of excessive calories for thermogenesis as opposed to storage in white adipose tissue (WAT) which would lead to weight gain. Over the past several years, BAT activity in vivo has been primarily assessed by positron emission tomography-computed tomography (PET-CT) scan using 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) to measure glucose utilization associated with BAT mitochondrial respiration.

Restoring cerebral dopamine homeostasis by electrical forepaw stimulation: an FMRI study.

Deviation of dopamine homeostasis is known to be associated with disorders like drug addiction and Parkinson's disease. As dopamine function is tightly regulated within the basal ganglia circuitry, cortical perturbation would lead to modulation of dopaminergic activity in the striatum. We proposed and tested if somatosensory activity such as forepaw stimulation could modulate dopaminergic function.

Record of a single fMRI experiment in May of 1991.

The discovery of BOLD fMRI at MGH in May 1991 was 1) built on the ongoing effort to develop new MR techniques for perfusion measurement with intrinsic blood contrast, 2) supported by the critical MGH expertise and experience on magnetic susceptibility and deoxyhemoglobin research, 3) inspired by the breakthrough in brain fMRI using dynamic susceptibility contrast (DSC) of the external contrast agent Gd-DTPA, 4) facilitated by the flow-BOLD insight of a hypoxia experiment, and 5) made possible by the availability of clinical echo planar imaging (EPI). The simultaneous demonstration of flow-weighted fMRI derived its intellectual origin from work on steady state arterial spin labeling (ASL). The free-wheeling and fertile intellectual environment structured by Dr.

Guasha-induced hepatoprotection in chronic active hepatitis B: a case study.

Background: Heme oxygenase-1 (HO-1) has demonstrated hepatoprotective effect in animal hepatitis models. HO-1 was also reported to be upregulated with Guasha, an ancient therapeutic technique which applies instrument assisted press-stroking to treat many disorders.

Methods: We report a case on the changes of liver function, plasma HO-1 and T-helper (Th) cytokine balance in a chronic active hepatitis B carrier before and after Guasha.

Early time points perfusion imaging: relative time of arrival, maximum derivatives and fractional derivatives.

Time of arrival (TOA) of a bolus of contrast agent to the tissue voxel is a reference time point critical for the Early Time Points Perfusion Imaging Method (ET) to make relative cerebral blood flow (rCBF) maps. Due to the low contrast to noise (CNR) condition at TOA, other useful reference time points known as relative time of arrival data points (rTOA) are investigated. Candidate rTOA's include the time to reach the maximum derivative, the maximum second derivative, and the maximum fractional derivative.