Age-related decrease in axonal transport measured by MR imaging in vivo

Cross, Donna; Flexman, Jennifer A.; Anzai, Yoshimi; Maravilla, Kenneth R.; Minoshima, Shinsei

doi:10.1016/j.neuroimage.2007.08.036

Cited by 47 publications

(48 citation statements)

References 44 publications

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“…Few studies have used SPM techniques in rats with different imaging modalities: autoradiographic iodoantipyrine [30][31][32][33][34], fMRI [35][36][37][38][39][40], and FDG-PET [20,41,42]. Two PET studies used a standardization according to a custom digital template matched to a highresolution microMRI image in Paxinos orientation [41,42].…”

Section: Discussionmentioning

confidence: 99%

Detection of Visual Activation in the Rat Brain Using 2-deoxy-2-[18F]fluoro-d-glucose and Statistical Parametric Mapping (SPM)

et al. 2008

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Purpose: This study was designed to assess changes in brain glucose metabolism in rats after visual stimulation. Materials and methods: We sought to determine whether visual activation in the rat brain could be detected using a small-animal positron emission tomography (PET) scanner and 2-deoxy-2-[ 18 F]fluoro-D-glucose (FDG). Eleven rats were divided into two groups: (a) five animals exposed to ambient light and (b) six animals stimulated by stroboscopic light (10 Hz) with one eye covered. Rats were injected with FDG and, after 45 min of visual stimulation, were sacrificed and scanned for 90 min in a dedicated PET tomograph. Images were reconstructed by a threedimensional ordered subset expectation maximization algorithm (1.8 mm full width at half maximum). A region-of-interest (ROI) analysis was performed on 14 brain structures drawn on coronal sections. Statistical parametric mapping (SPM) adapted for small animals was also carried out. Additionally, the brains of three rats were sliced into 20-μm sections for autoradiography. Results: Analysis of ROI data revealed significant differences between groups in the right superior colliculus, right thalamus, and brainstem (p≤0.05). SPM detected the same areas as the ROI approach. Autoradiographs confirmed the existence of hyperactivation in the left superior colliculus and auditory cortex. Conclusions: To our knowledge, this is the first report that uses FDG-PET and SPM analysis to show changes in rat brain glucose metabolism after a visual stimulus.

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Section: Discussionmentioning

confidence: 99%

Detection of Visual Activation in the Rat Brain Using 2-deoxy-2-[18F]fluoro-d-glucose and Statistical Parametric Mapping (SPM)

et al. 2008

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“…Since then, MEMRI has become an established technique for in vivo anatomical CNS tract-tracing in various animal models (9)(10)(11)(12)(13) and has recently been extended to dynamic tracing (14)(15)(16). MEMRI utilizes the paramagnetic property of the manganese ion (Mn 2þ ) and takes advantage of Mn 2þ being a calcium (Ca 2þ ) analog in biological systems.…”

mentioning

confidence: 99%

“…Even though Mn 2þ CNS axonal transport rates have been reported in various studies (9)(10)(11)(12)(13)16), a more thorough investigation of Mn 2þ transport that addresses issues like entering of Mn 2þ into axons, multiple transport rates, and axonal clearance are needed before MEMRI has application in in vivo studies of neurodegenerative diseases. The previous studies used two timepoints and positions to estimate transport rates, while several positions and timepoints are needed to reveal multiple transport rates.…”

mentioning

confidence: 99%

Manganese transport in the rat optic nerve evaluated with spatial‐ and time‐resolved magnetic resonance imaging

Olsen

Kristoffersen

Thuen

et al. 2010

Magnetic Resonance Imaging

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Purpose: 1) To evaluate a novel theoretical model for in vivo axonal Mn 2þ transport with MRI data from the rat optic nerve (ON); and 2) to compare predictions from the new model with previously reported experimental data. Materials and Methods:Time-resolved in vivo T 1 -weighted magnetic resonance imaging (MRI) of adult female Sprague-Dawley rat (n ¼ 9) ON was obtained at different timepoints after intravitreal MnCl 2 injection. A concentration-dependent and a rate-dependent function for the Mn 2þ retinal ganglion cell (RGC) axon entrance was convolved with three different transport functions and each model system was optimized to fit the ON data.Results: The rate-limited input function gave a better fit to the data than the concentration-limited input. Simulations showed that the rate-limited input leads to a semilogarithmic relationship between injected dose and Mn 2þ concentration in the ON, which is in agreement with previously reported in vivo experiments. A random walk transport model and an anterograde predominant slow model gave a similar fit to the data, both better than an anterograde predominant fast model. Conclusion:The results indicate that Mn 2þ input into RGC axons is limited by a maximum entrance rate into the axons. Also, a wide range of apparent Mn 2þ transport rates seems to be involved, different from synaptic vesicle transport rates, meaning that manganese does not depict synaptic vesicle transport rates directly.

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“…[13][14][15][16][17][18] With these techniques, spatial normalization of the brain permits voxel-based analysis of the entire brain and more objective results than those of conventional ROI/VOI analysis. The results are less susceptible to changes in subject shape and size, and position, shape, and size of the ROI/VOI do not vary between observers.…”

Section: Magnetic Resonance In Medical Sciencesmentioning

confidence: 99%

“…[13][14][15] These methods using MEMRI are expected to become a basic and important method for rat brain research, so their applicability for such investigation requires validation. We applied Statistical Parametric Mapping 8 software (SPM8; Wellcome Department of Cognitive Neurology, London, UK [http://www.ˆl.ion.…”

Section: Magnetic Resonance In Medical Sciencesmentioning

confidence: 99%

Statistical Parametric Mapping for Effects of Verapamil on Olfactory Connections of Rat Brain in Vivo using Manganese-enhanced MR Imaging

et al. 2011

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Purpose: We investigated the eŠect of verapamil on the transport of manganese in the olfactory connections of rat brains in vivo using statistical parametric mapping and manganese-enhanced magnetic resonance (MR) imaging.Methods: We divided 12 7-week-old male Sprague-Dawley rats into 2 groups of six and injected 10 mL of saline into the right nasal cavities of theˆrst group and 10 mL of verapamil (2.5 mg/mL) into the other group. Twenty minutes after the initial injection, we injected 10 mL of MnCl 2 (1 mol/L) into the right nasal cavities of both groups. We obtained serial T 1 -weighted MR images before administering the verapamil or saline and at 0.5, one, 24, 48, and 72 hours and 7 days after administering the MnCl 2 , spatially normalized the MR images on the rat brain atlas, and analyzed the data using voxel-based statistical comparison.Results: Statistical parametric maps demonstrated the transport of manganese. Manganese ions created signiˆcant enhancement (t-score＝36.6) 24 hours after MnCl 2 administration in the group administered saline but not at the same time point in the group receiving verapamil. The extent of signiˆcantly enhanced regions peaked at 72 hours in both groups and both sides of the brain. The peak of extent in the right side brain in the group injected with saline was 70.2 mm 3 and in the group with verapamil, 92.4 mm 3 . The extents in the left side were 64.0 mm 3 for the group with saline and 53.2 mm 3 for the group with verapamil.Conclusion: We applied statistical parametric mapping using manganese-enhanced MR imaging to demonstrate in vivo the transport of manganese in the olfactory connections of rat brains with and without verapamil and found that verapamil did aŠect this transport.

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Age-related decrease in axonal transport measured by MR imaging in vivo

Cited by 47 publications

References 44 publications

Detection of Visual Activation in the Rat Brain Using 2-deoxy-2-[18F]fluoro-d-glucose and Statistical Parametric Mapping (SPM)

Detection of Visual Activation in the Rat Brain Using 2-deoxy-2-[18F]fluoro-d-glucose and Statistical Parametric Mapping (SPM)

Manganese transport in the rat optic nerve evaluated with spatial‐ and time‐resolved magnetic resonance imaging

Statistical Parametric Mapping for Effects of Verapamil on Olfactory Connections of Rat Brain in Vivo using Manganese-enhanced MR Imaging

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