New rat model of spinal cord infarction with long-lasting functional disabilities generated by intraspinal injection of endothelin-1.

Background: The current method for generating an animal model of spinal cord (SC) infarction is highly invasive and permits only short-term observation, typically limited to 28 days.

Objective: We aimed to establish a rat model characterised by long-term survival and enduring SC dysfunction by inducing selective ischaemic SC damage.

Methods: In 8-week-old male Wistar rats, a convection-enhanced delivery technique was applied to selectively deliver endothelin-1 (ET-1) to the anterior horn of the SC at the Th13 level, leading to SC infarction.

Structural alterations in the amygdala and impaired social incentive learning in a mouse model of a genetic variant associated with neurodevelopmental disorders.

Copy number variants (CNVs) are robustly associated with psychiatric disorders and their dimensions and changes in brain structures and behavior. However, as CNVs contain many genes, the precise gene-phenotype relationship remains unclear. Although various volumetric alterations in the brains of 22q11.

Tbx1, a gene encoded in 22q11.2 copy number variant, is a link between alterations in fimbria myelination and cognitive speed in mice.

Copy number variants (CNVs) have provided a reliable entry point to identify the structural correlates of atypical cognitive development. Hemizygous deletion of human chromosome 22q11.2 is associated with impaired cognitive function; however, the mechanisms by which the CNVs contribute to cognitive deficits via diverse structural alterations in the brain remain unclear.

Convection-enhanced delivery of a hydrophilic nitrosourea ameliorates deficits and suppresses tumor growth in experimental spinal cord glioma models.

Background: Convection-enhanced delivery (CED) is a technique allowing local infusion of therapeutic agents into the central nervous system, circumventing the blood-brain or spinal cord barrier.

Objective: To evaluate the utility of nimustine hydrochloride (ACNU) CED in controlling tumor progression in an experimental spinal cord glioma model.

Methods: Toxicity studies were performed in 42 rats following the administration of 4 μl of ACNU CED into the mid-thoracic spinal cord at concentrations ranging from 0.

Sexual differentiation of the adolescent rat brain: A longitudinal voxel-based morphometry study.

The sexual differentiation of the rat brain during the adolescent period has been well documented in post-mortem histological studies. However, to further understand the morphological changes occurring in the entire brain, a noninvasive neuroimaging method allowing an unbiased, comprehensive, and longitudinal investigation of brain morphology should be used. In this study, we investigated the sexual differentiation of the rat brain during the adolescent period using longitudinal voxel-based morphometry (VBM) analysis.

Regional Volume Decreases in the Brain of Pax6 Heterozygous Mutant Rats: MRI Deformation-Based Morphometry.

Pax6 is a transcription factor that pleiotropically regulates various developmental processes in the central nervous system. In a previous study, we revealed that Pax6 heterozygous mutant (rSey2/+) adult rats exhibit abnormalities in social interaction. However, the brain malformations underlying the behavioral abnormality are unknown.

Intraparenchymal ultrasound application and improved distribution of infusate with convection-enhanced delivery in rodent and nonhuman primate brain.

OBJECT Convection-enhanced delivery (CED) is an effective drug delivery method that delivers high concentrations of drugs directly into the targeted lesion beyond the blood-brain barrier. However, the drug distribution attained using CED has not satisfactorily covered the entire targeted lesion in tumors such as glioma. Recently, the efficacy of ultrasound assistance was reported for various drug delivery applications.

Prevention of cancer recurrence in tumor margins by stopping microcirculation in the tumor and tumor-host interface.

Combretastatins interrupt blood flow of solid tumor vascular networks and lead to necrosis by blocking nutrients. However, tumors recover from tumor blood flow interruption-induced damage and develop viable rims. To investigate why cancer recurs and its prevention, we used a combretastatin derivative, Cderiv (=AC7700), and analyzed changes in tumor-host interface (T-HI) vessels, which were closest to cancer cells in the tumor margin after tumor vessel disruption, and the microenvironment surrounding them.

Specific regions display altered grey matter volume in μ-opioid receptor knockout mice: MRI voxel-based morphometry.

Background And Purpose: μ Opioid receptor knockout (MOP-KO) mice display several behavioural differences from wild-type (WT) littermates including differential responses to nociceptive stimuli. Brain structural changes have been tied to behavioural alterations noted in transgenic mice with targeting of different genes. Hence, we assess the brain structure of MOP-KO mice.

Regional gray matter volume increases following 7days of voluntary wheel running exercise: a longitudinal VBM study in rats.

The effects of physical exercise on brain morphology in rodents have been well documented in histological studies. However, to further understand when and where morphological changes occur in the whole brain, a noninvasive neuroimaging method allowing an unbiased, comprehensive, and longitudinal investigation of brain morphology should be used. In this study, we investigated the effects of 7days of voluntary wheel running exercise on regional gray matter volume (rGMV) using longitudinal voxel-based morphometry (VBM) in rats.

Pitfalls in the dipolar model for the neocortical EEG sources.

For about six decades, primary current sources of the electroencephalogram (EEG) have been assumed dipolar in nature. In this study, we used electrophysiological recordings from anesthetized Wistar rats undergoing repeated whisker deflections to revise the biophysical foundations of the EEG dipolar model. In a first experiment, we performed three-dimensional recordings of extracellular potentials from a large portion of the barrel field to estimate intracortical multipolar moments generated either by single spiking neurons (i.

An in vivo MRI Template Set for Morphometry, Tissue Segmentation, and fMRI Localization in Rats.

Over the last decade, several papers have focused on the construction of highly detailed mouse high field magnetic resonance image (MRI) templates via non-linear registration to unbiased reference spaces, allowing for a variety of neuroimaging applications such as robust morphometric analyses. However, work in rats has only provided medium field MRI averages based on linear registration to biased spaces with the sole purpose of approximate functional MRI (fMRI) localization. This precludes any morphometric analysis in spite of the need of exploring in detail the neuroanatomical substrates of diseases in a recent advent of rat models.

Large-scale heterogeneous representation of sound attributes in rat primary auditory cortex: from unit activity to population dynamics.

Recent evidence indicates the existence of pyramidal cells (PCs) and interneurons with nontrivial tuning characteristics for sound attributes in the primary auditory cortex (A1) of mammals. These neurons are functionally distributed into layers and sparsely organized at a small scale. However, their topological locations at a large scale in A1 have not yet been investigated.

A case of adult-onset type II citrullinemia with comorbid epilepsy even after liver transplantation.

The current study using single case voxel-based morphometry (VBM) of magnetic resonance imaging (MRI) and ¹H-MR-spectroscopy (¹H-MRS) explores the neural background of unexplained seizure attacks and electroencephalography (EEG) abnormalities persisting even after liver transplantation in a patient with adult-onset type II citrullinemia (CTLN2). Although the MRI had shown no gross abnormality, the VBM revealed significantly smaller-than-normal regional volume in the left hippocampus of the patient as compared with 111 age-matched controls. ¹H-MRS further indicated reduction of all metabolite concentrations in the left hippocampus compared with those in the right homolog region, with the single exception of elevated glutamate concentration.

Specific metabolites in the medial prefrontal cortex are associated with the neurocognitive deficits in schizophrenia: a preliminary study.

We measured brain metabolites in the medial prefrontal cortex of 19 schizophrenic patients and 18 healthy controls by 3 T proton magnetic resonance spectroscopy ((1)H MRS), and examined the relationship between prefrontal cortex-related neurocognitive functions and brain metabolites in the medial prefrontal cortex. The patients with schizophrenia exhibited deficits on the verbal fluency, Wisconsin card sorting test (WCST), trail making test, Stroop test and digit span distraction test (DSDT), but not on the Iowa gambling test. The patients showed statistical significant changes in the ratio of glutamine/glutamate, the ratio of N-acetyl-l-aspartate (NAA)/glycerophosphorylcholine plus phosphorylcholine (GPC+PC) and the levels of taurine in the medial prefrontal cortex compared with normal controls.

A multi-compartmental SE-BOLD interpretation for stimulus-related signal changes in diffusion-weighted functional MRI.

A new interpretation is proposed for stimulus-induced signal changes in diffusion-weighted functional MRI. T(2)-weighted spin-echo echo-planar images were acquired at different diffusion-weightings while visual stimulation was presented to human volunteers. The amplitudes of the positive stimulus-correlated response and post-stimulus undershoot (PSU) in the functional time-courses were found to follow different trends as a function of b-value.

Analgesic effect of milnacipran is associated with c-Fos expression in the anterior cingulate cortex in the rat neuropathic pain model.

The objective of the present study was to examine whether milnacipran, a serotonin-noradrenaline reuptake inhibitor, has an analgesic effect in rats with neuropathic pain. In addition, the c-Fos expression was investigated in the supraspinal sites of the brain and in the spinal dorsal horn in association with the nociceptive processing in rats with neuropathic pain produced by chronic constriction injury (CCI) in the sciatic nerve. In the CCI-induced neuropathic rats, behavioral testing for determining the change in the withdrawal threshold to mechanical stimulation and immunohistochemical detection of c-Fos were both performed.

A new approach for diagnosis of hepatolithiasis: magnetic resonance cholangiopancreatography: potential usefulness of dehydrocholic acid (DHCA) administration in the evaluation of hepatolithiasis.

Background/aims: The aim of this study was to investigate whether exogenous dehydrocholic acid (DHCA) was useful to enhance the delineation of hepatolithiasis.

Methodology: Our study population comprised 9 patients. Magnetic resonance cholangiopancreatography (MRCP) was acquired before and after the administration of DHCA.

Monitoring of liver glycogen synthesis in diabetic patients using carbon-13 MR spectroscopy.

To investigate the relationship between liver glucose, glycogen, and plasma glucose in diabetic patients, in vivo liver carbon-13 magnetic resonance spectroscopy ((13)C MRS) with a clinical 3.0T MR system was performed. Subjects were healthy male volunteers (n=5) and male type-2 diabetic patients (n=5).

Functional difference between rat perirhinal cortex and hippocampus in object and place discrimination tasks.

The present study was designed to determine the degree of functional dissociation between the rat perirhinal cortex and hippocampus for reference memory performance on object and place discrimination tasks. In one experiment, 30 rats were trained on a two-pair concurrent object discrimination task in an elevated radial arm maze. Rats with a perirhinal cortex lesion needed significantly more days to attain the criterion in the relearning of a pre-operatively acquired object discrimination task than the control rats and rats with a hippocampal lesion.