Sequence of forebrain activation induced by intraventricular injection of hypertonic NaCl detected by Mn2+ contrasted T1-weighted MRI

Morita, Hironobu; Ogino, Takashi; Fujiki, Nobuhiro; Tanaka, Kunihiko; Gotoh, Taro Miyahara; Seo, Yoshiteru; Takamata, Akira; Nakamura, Shun; Murakami, Masataka

doi:10.1016/j.autneu.2004.05.005

Cited by 23 publications

(19 citation statements)

References 34 publications

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“…A couple of reports on direct, interechal administration of MnCl 2 shows good promise in delivering large amounts of MnCl 2 to the brain without the complications of a large systemic dose. 22,49 The combination of clever ways to deliver Mn 2þ with further improvements in the ability to detect Mn 2þ would make it possible to use MEMRI in humans. …”

Section: Discussionmentioning

confidence: 99%

“…Whether the tonicity of the MnCl 2 solution will play an important effect on the experiment depends on the relative volume of infusion with respect to the target tissue. For systemic infusions, such as intravenous or intraperitoneal administration, the tonicity of the solution may be of little consequence, but for targeted injections, such as stereotaxic brain infusions, [12][13][14]22 it may have a strong local impact.…”

Section: Manganese Chloride As a Source Of Mn 2þ Preparation Of Mncl mentioning

confidence: 99%

“…A useful buffer to keep the pH within physiological levels for use with MnCl 2 solution is bicine (product number B3876, Sigma-Aldrich Co., St Louis, MO, USA) dissolved to 100 mM in deionized water and adjusted to pH 7.4 using NaOH. 22 MnCl 2 is then added to the bicine solution at 100 mM concentration. This recipe should provide the investigator with a solution of MnCl 2 at physiological pH, which is suitable for most MEMRI experiments.…”

Section: Manganese Chloride As a Source Of Mn 2þ Preparation Of Mncl mentioning

confidence: 99%

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Manganese‐enhanced magnetic resonance imaging (MEMRI): methodological and practical considerations

et al. 2004

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Manganese-enhanced MRI (MEMRI) is being increasingly used for MRI in animals due to the unique T 1 contrast that is sensitive to a number of biological processes. Three specific uses of MEMRI have been demonstrated: to visualize activity in the brain and the heart; to trace neuronal specific connections in the brain; and to enhance the brain cytoarchitecture after a systemic dose. Based on an ever-growing number of applications, MEMRI is proving useful as a new molecular imaging method to visualize functional neural circuits and anatomy as well as function in the brain in vivo. Paramount to the successful application of MEMRI is the ability to deliver Mn 2þ to the site of interest at an appropriate dose and in a time-efficient manner. A major drawback to the use of Mn 2þ as a contrast agent is its cellular toxicity. Therefore, it is critical to use as low a dose as possible. In the present work the different approaches to MEMRI are reviewed from a practical standpoint. Emphasis is given to the experimental methodology of how to achieve significant, yet safe, amounts of Mn 2þ to the target areas of interest.

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Section: Discussionmentioning

confidence: 99%

Section: Manganese Chloride As a Source Of Mn 2þ Preparation Of Mncl mentioning

confidence: 99%

Section: Manganese Chloride As a Source Of Mn 2þ Preparation Of Mncl mentioning

confidence: 99%

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Manganese‐enhanced magnetic resonance imaging (MEMRI): methodological and practical considerations

et al. 2004

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“…Use of BBB-disrupting agents, as in other MEMRI studies (Aoki et al, 2002;Morita et al, 2004), would result in loss of the differential access to CNS structures on which gut peptide activity depends (Batterham et al, 2002;Stanley et al, 2005). We have previously shown that intravenous administration of MnCl 2 causes significant T 1 shortening within 1 h in the hypothalamus, even when BBB integrity is preserved (Kuo et al, 2005;Chaudhri et al, 2006;Kuo et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

“…These channels are found on neurons, and therefore Mn 2ϩ accumulates in neurons in an activity-dependent manner. Thus, MEMRI is well suited to studies of neuroarchitecture and neuronal connections (Lin and Koretsky, 1997;Saleem et al, 2002;Pautler, 2004;Van der Linden et al, 2004;Watanabe et al, 2004) and to the monitoring of the neuronal response to stimuli such as somatosensory stimulation (Aoki et al, 2002) and injection of hypertonic saline (Morita et al, 2004) in rodents.…”

Section: Introductionmentioning

confidence: 99%

The Temporal Sequence of Gut Peptide–CNS Interactions TrackedIn Vivoby Magnetic Resonance Imaging

Kuo

Parkinson²,

Chaudhri³

et al. 2007

J. Neurosci.

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Hormonal satiety signals secreted by the gut play a pivotal role in the physiological control of appetite. However, therapeutic exploitation of the gut-brain axis requires greater insight into the interaction of gut hormones with CNS circuits of appetite control. Using the manganese ion (Mn 2ϩ ) as an activity-dependent magnetic resonance imaging (MRI) contrast agent, we showed an increase in signal intensity (SI) in key appetite-regulatory regions of the hypothalamus, including the arcuate, paraventricular, and ventromedial nuclei, after peripheral injection of the orexigenic peptide ghrelin. Conversely, administration of the anorexigenic hormone peptide YY 3-36 caused a reduction in SI. In both cases, the changes in SI recorded in the hypothalamic arcuate nucleus preceded the effect of these peptides on food intake. Intravenous Mn 2ϩ itself did not significantly alter ghrelin-mediated expression of the immediate early gene product c-Fos, nor did it cause abnormalities of behavior or metabolic parameters. We conclude that manganese-enhanced MRI constitutes a powerful tool for the future investigation of the effects of drugs, hormones, and environmental influences on neuronal activity.

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Mn‐citrate and Mn‐HIDA: intermediate‐affinity chelates for manganese‐enhanced MRI

Seo

Satoh

Morita³

et al. 2012

Contrast Media & Molecular

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In this study we investigated two manganese chelates in order to improve the image enhancement of manganese-enhanced MRI and decrease the toxicity of free manganese ions. Since both MnCl₂ and a low-affinity chelate were associated with a slow continuous decrease of cardiac functions, we investigated intermediate-affinity chelates: manganese N-(2-hydroxyethyl)iminodiacetic acid (Mn-HIDA) and Mn-citrate. The T₁ relaxivity values for Mn-citrate (4.4 m m⁻¹ s⁻¹) and Mn-HIDA (3.3 m m⁻¹ s⁻¹) in artificial cerebrospinal fluid (CSF) were almost constant in a concentration range from 0.5 to 5 m m at 37 °C and 4.7 T. In human plasma, the relaxivity values increased when the concentrations of these Mn chelates were decreased, suggesting the presence of free Mn²⁺ bound with serum albumin. Mn-HIDA and Mn-citrate demonstrated a tendency for better contractility when employed with an isolated perfused frog heart, compared with MnCl₂. Only minimal changes were demonstrated after a venous infusion of 100 m m Mn-citrate or Mn-HIDA (8.3 µmol kg⁻¹ min⁻¹) in rats and a constant heart rate, arterial pressure and sympathetic nerve activity were maintained, even after breaking the blood-brain barrier (BBB). Mn-citrate and Mn-HIDA could not cross the intact BBB and appeared in the CSF, and then diffused into the brain parenchyma through the ependymal layer. The responses in the supraoptic nucleus induced by the hypertonic stimulation were detectable. Therefore, Mn-citrate and Mn-HIDA appear to be better choices for maintaining the vital conditions of experimental animals, and they may improve the reproducibility of manganese-enhanced MRI of the small nuclei in the hypothalamus and thalamus.

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Sequence of forebrain activation induced by intraventricular injection of hypertonic NaCl detected by Mn2+ contrasted T1-weighted MRI

Cited by 23 publications

References 34 publications

Manganese‐enhanced magnetic resonance imaging (MEMRI): methodological and practical considerations

Manganese‐enhanced magnetic resonance imaging (MEMRI): methodological and practical considerations

The Temporal Sequence of Gut Peptide–CNS Interactions TrackedIn Vivoby Magnetic Resonance Imaging

Mn‐citrate and Mn‐HIDA: intermediate‐affinity chelates for manganese‐enhanced MRI

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