Effects of temporarily disrupting BBB on activity-induced manganese-dependent functional MRI

Fa, Zhiqiang; Zhang, Run; Zhang, Jing; Zhang, Peng; Zhu, Shaofang; Qu, Wenyu; Huang, Fanheng; Liu, Yanping; Yang, Lüjun; Chang, Haigang; Wen, Zhibo; Gao, Dingguo; Zeng, Yanjun; Jiang, Xiao-dan

doi:10.1007/s11682-011-9122-7

Cited by 4 publications

(3 citation statements)

References 21 publications

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“…BBB disruption in the visual cortex has been shown previously in a rat model to alter the functional MRI response to different visual stimuli . We hypothesise that increased BBB permeability (ie, BBB disruption) in the occipital lobe might have a negative impact on visual acuity in type 2 diabetics with established BRB leakage.…”

Section: Discussionmentioning

confidence: 84%

Occipital blood‐brain barrier permeability is an independent predictor of visual outcome in type 2 diabetes, irrespective of the retinal barrier: A longitudinal study

Abuhaiba

Cordeiro

Amorim

et al. 2018

J Neuroendocrinology

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Blood‐brain barrier (BBB) permeability in type 2 diabetic patients has been previously shown to be altered in certain brain regions such as the basal ganglia and the hippocampus. Because of the histological and functional similarities between the BBB) and the blood‐retinal barrier (BRB), we aimed to investigate how the permeability of both barriers predicts visual outcome. We included 2 control groups (acute unilateral stroke patients, n = 9; type 2 diabetics without BRB leakage n = 10) and a case study group of type 2 diabetics with established BRB leakage (n = 17). We evaluated sex, age, disease duration, metabolic impairment, retinopathy grade and BBB permeability as predictors of visual acuity at baseline, 12 and 24 months in the type 2 diabetics without BRB leakage group and the case study group. We have also explored differences in BBB permeability in the occipital lobe and frontal lobe in the 3 different groups. Ktrans (volume transfer coefficient) and Vp (fractional plasma volume) were estimated. The BBB permeability parameter Vp was higher in the case study group compared to the unaffected hemisphere of the stroke patient control group, suggesting vascular dynamics were changed in the occipital lobe of type 2 diabetics with established BRB leakage. These patients showed a significant correlation between glycated hemoglobin (HbA1C) levels and occipital and frontal Ktrans. We report for the first time that occipital BBB permeability is an independent predictor of visual acuity at baseline, as well as at 12 and 24 months, in type 2 diabetics with established BRB leakage. Our results suggest that occipital BBB permeability might be an independent biomarker for visual impairment in patients with established BRB leakage.

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Section: Discussionmentioning

confidence: 84%

Occipital blood‐brain barrier permeability is an independent predictor of visual outcome in type 2 diabetes, irrespective of the retinal barrier: A longitudinal study

Abuhaiba

Cordeiro

Amorim

et al. 2018

J Neuroendocrinology

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“…However, the blood–brain and blood–retinal barriers pose a challenge when it comes to standardizing doses of systemic Mn 2+ administration to maximize bioavailability and neuroenhancement while avoiding systemic toxicity. Hyperosmolar agents can be used to temporarily breach the blood–brain barrier to improve Mn 2+ entry in the visual cortex and other brain regions after systemic Mn 2+ infusion (Aoki et al, 2002; Fa et al, 2011). Alternatively, low MnCl 2 concentrations have been successfully administered intravenously in fractionated doses to enhance the primary visual cortex in marmosets (Bock et al, 2009), as well as the periventricular areas in rodents without compromising the blood–brain barrier (Talley Watts et al, 2015; Alaverdashvili et al, 2017).…”

Section: Routes Of Administrationmentioning

confidence: 99%

“…Cortical activity mediated through visual stimuli in awake and free-moving rats can also be imaged by MEMRI after systemic MnCl 2 injection with or without temporarily opening the blood–brain barrier (Bissig and Berkowitz, 2009; Fa et al, 2011). Rats that received visual stimulation demonstrated significantly higher MEMRI signal intensities in layers IV and V of the primary visual cortex relative to the dark-adapted rats (Bissig and Berkowitz, 2009) (Figure 3C).…”

Section: Evaluation Of Neuronal Activitymentioning

confidence: 99%

Applications of Manganese-Enhanced Magnetic Resonance Imaging in Ophthalmology and Visual Neuroscience

Deng

Faiq

Liu

et al. 2019

Front. Neural Circuits

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Understanding the mechanisms of vision in health and disease requires knowledge of the anatomy and physiology of the eye and the neural pathways relevant to visual perception. As such, development of imaging techniques for the visual system is crucial for unveiling the neural basis of visual function or impairment. Magnetic resonance imaging (MRI) offers non-invasive probing of the structure and function of the neural circuits without depth limitation, and can help identify abnormalities in brain tissues in vivo . Among the advanced MRI techniques, manganese-enhanced MRI (MEMRI) involves the use of active manganese contrast agents that positively enhance brain tissue signals in T1-weighted imaging with respect to the levels of connectivity and activity. Depending on the routes of administration, accumulation of manganese ions in the eye and the visual pathways can be attributed to systemic distribution or their local transport across axons in an anterograde fashion, entering the neurons through voltage-gated calcium channels. The use of the paramagnetic manganese contrast in MRI has a wide range of applications in the visual system from imaging neurodevelopment to assessing and monitoring neurodegeneration, neuroplasticity, neuroprotection, and neuroregeneration. In this review, we present four major domains of scientific inquiry where MEMRI can be put to imperative use — deciphering neuroarchitecture, tracing neuronal tracts, detecting neuronal activity, and identifying or differentiating glial activity. We deliberate upon each category studies that have successfully employed MEMRI to examine the visual system, including the delivery protocols, spatiotemporal characteristics, and biophysical interpretation. Based on this literature, we have identified some critical challenges in the field in terms of toxicity, and sensitivity and specificity of manganese enhancement. We also discuss the pitfalls and alternatives of MEMRI which will provide new avenues to explore in the future.

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Quantitative activity-induced manganese-dependent MRI for characterizing cortical layers in the primary somatosensory cortex of the rat

et al. 2014

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The ability of Mn 2? to follow Ca 2? pathways upon stimulation transform them into remarkable surrogate markers of neuronal activity using activity-induced manganese-dependent MRI (AIM-MRI). In the present study, a precise follow-up of physiological parameters during MnCl 2 and mannitol infusions improved the reproducibility of AIM-MRI allowing in-depth evaluation of the technique. Pixel-by-pixel T 1 data were investigated using histogram distributions in the barrel cortex (BC) and the thalamus before and after Mn 2? infusion, after blood brain barrier opening and after BC activation. Mean BC T 1 values dropped significantly upon trigeminal nerve (TGN) stimulation (-38 %, P = 0.02) in accordance with previous literature findings. T 1 histogram distributions showed that 34 % of T 1s in the range 600-1500 ms after Mn 2? ? mannitol infusions shifted to 50-350 ms after TGN stimulation corresponding to a twofold increase of the percentage of pixels with the lowest T 1s in BC. Moreover, T 1 changes in response to stimulation increased significantly from superficial cortical layers (I-III) to deeper layers (V-VI). Cortical cytoarchitecture detection during a functional paradigm was performed extending the potential of AIM-MRI. Quantitative AIM-MRI could thus offer a means to interpret local neural activity across cortical layers while identification of the role of calcium dynamics in vivo during brain activation could play a key role in resolving neurovascular coupling mechanisms.

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Effects of temporarily disrupting BBB on activity-induced manganese-dependent functional MRI

Cited by 4 publications

References 21 publications

Occipital blood‐brain barrier permeability is an independent predictor of visual outcome in type 2 diabetes, irrespective of the retinal barrier: A longitudinal study

Occipital blood‐brain barrier permeability is an independent predictor of visual outcome in type 2 diabetes, irrespective of the retinal barrier: A longitudinal study

Applications of Manganese-Enhanced Magnetic Resonance Imaging in Ophthalmology and Visual Neuroscience

Quantitative activity-induced manganese-dependent MRI for characterizing cortical layers in the primary somatosensory cortex of the rat

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