Fingolimod as a Potential Cerebroprotectant Results From the Stroke Preclinical Assessment Network.

Background: Fingolimod is an immunomodulatory drug that has shown promising effects in stroke treatment, including improvements in neurofunctional recovery and a reduction in infarct size. Fingolimod modulates the sphingosine-1-phosphate receptors, which leads to the internalization of sphingosine-1-phosphate receptors on T and B lymphocytes, thereby preventing their egress from secondary lymphoid organs. Here, we report a secondary analysis from the Stroke Preclinical Assessment Network trial.

The Microglial TREM2 Receptor Programs Hippocampal Development in a Mouse Model of Childhood Deprivation.

Childhood neglect and deprivation are the most common forms of adversity, yet their biological impact on cognitive development-and how enrichment mitigates these effects-remains unclear. Using limited bedding (LB) as a mouse model of deprivation, we previously showed that abnormal microglial-mediated synaptic pruning during the second and third postnatal weeks leads to impaired synaptic connectivity and hippocampal dysfunction, particularly in males. Here, we demonstrate that LB reduces expression of Triggering Receptor Expressed on Myeloid cells 2 (TREM2) in different mouse strains and that TREM2 deficiency contributes to, but does not fully explain, impaired microglial pruning.

[F]SynVesT-1 PET Detects SV2A Changes in the Spinal Cord and Brain of Rats with Spinal Cord Injury.

Traumatic spinal cord injury (SCI) is a devastating neurologic condition lacking effective prognostic and treatment methods. PET imaging of synaptic vesicle glycoprotein 2A (SV2A) has been used in measuring synapse changes. We explore the feasibility of using [F]SynVesT-1 PET to detect the synaptic changes in a rat model of SCI.

Mapping of neurovascular and neurometabolic couplings by multimodal optical imaging.

Neurovascular coupling links calcium (Ca2+)-dependent neuronal activity to cerebral blood volume changes, whereas neurometabolic coupling describes alterations of neuronal activity and glucose uptake. While mesoscale optical imaging of neurovascular coupling is prevalent, neurometabolic coupling has been explored much less. We describe a multiplexed optical system with a closed cranial window setup for longitudinal studies in Thy1-jRGECO1a mice where neuronal activity is measured with Ca2+-dependent red fluorescence, glucose uptake with bolus injections of 2NBDG with green fluorescence, and cerebral blood volume (CBV) with near-infrared spectroscopy (NIRS).

Cysteine depletion triggers adipose tissue thermogenesis and weight loss.

Caloric restriction and methionine restriction-driven enhanced lifespan and healthspan induces 'browning' of white adipose tissue, a metabolic response that increases heat production to defend core body temperature. However, how specific dietary amino acids control adipose thermogenesis is unknown. Here, we identified that weight loss induced by caloric restriction in humans reduces thiol-containing sulfur amino acid cysteine in white adipose tissue.

Intranasal Leukemia Inhibitory Factor as a late-stage treatment for delayed white matter damage in concussive head injury.

Leukemia Inhibitory Factor (LIF) is an injury-induced cytokine that peaks 48 hours after a traumatic brain injury (TBI). Juvenile LIF haplodeficient mice exhibit desynchronized glial responses, increased neurodegeneration, decreased axonal conductivity and behavioral deficits after a concussive head injury. Given the necessity of LIF during the acute recovery phase after injury, we hypothesized that intranasal (IN) LIF treatment would prevent neurodegeneration when administered during the chronic recovery period from a mild TBI (mTBI).

Commentary to "Task activation results in regional C-lactate signal increase in the human brain".

Metabolism is fundamental to functional brain imaging. While functional MRI (fMRI) has greatly benefited neuroscience, C-MRS measures coupling between neuroenergetics and neurotransmission. However, a hyperpolarized C-MRI study in human brain shows increased C-lactate (i.

Reduced removal of waste products from energy metabolism takes center stage in human brain aging.

Despite extensive research on neuroimaging correlates of human brain aging, there is little mechanistic insight into how they are linked to loss of brain function. Previous studies on the role of cerebral blood flow (CBF) in supporting brain function have focused on delivery of nutrients, namely oxygen and glucose. However, CBF is required also to clear the byproducts of energy metabolism, namely CO and protons.

Molecular MRI of T-cell immune response to cryoablation in immunologically hot . cold hepatocellular carcinoma.

Background & Aims: Increasing enthusiasm around integrating locoregional therapy with systemic immunotherapy in primary liver cancer underscores the need for non-invasive imaging biomarkers. In this study, we aimed to establish advanced molecular MRI tools for monitoring T-cell responses to cryoablation in murine models, distinguishing between immunologically "hot" and "cold" hepatocellular carcinoma (HCC).

Methods: Immunocompetent 7-10-week-old C57BL/6J and BALB/cJ mice (n = 18 each) received carbon tetrachloride for 12 weeks to induce cirrhosis.

Autism-associated variant causes macrocephaly and social-cognitive deficits in mice.

In autism spectrum disorder (ASD), a neurodevelopmental disorder with social-cognitive deficits, macrocephaly occurs in 20% of patients with severe symptoms. However, the role of macrocephaly in ASD pathogenesis remains unclear. Here, we address the mechanistic link between macrocephaly and ASD by investigating a novel ASD-associated gain-of-function A1877T mutation in ( ).

Sorafenib Alters Interstitial Proton and Sodium Levels in the Tumor Microenvironment: A H/Na Spectroscopic Imaging Study.

Cellular metabolism is inextricably linked to transmembrane levels of proton (H), sodium (Na), and potassium (K) ions. Although reduced sodium-potassium pump (Na-K ATPase) activity in tumors directly disturbs transmembrane Na and K levels, this dysfunction is a result of upregulated aerobic glycolysis generating excessive cytosolic H (and lactate) which are extruded to acidify the interstitial space. These oncogene-directed metabolic changes, affecting intracellular Na and H, can be further exacerbated by upregulation of ion exchangers/transporters.

Complexes of Iron(II), Cobalt(II), and Nickel(II) with DOTA-Tetraglycinate for pH and Temperature Imaging Using Hyperfine Shifts of an Amide Moiety.

Paramagnetic complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) derivatives have shown potential for molecular imaging with magnetic resonance. DOTA-tetraglycinate (DOTA-4AmC) coordinated with lanthanide metal ions (Ln) demonstrates pH/temperature sensing with Biosensor Imaging of Redundant Deviation in Shifts (BIRDS) and Chemical Exchange Saturation Transfer (CEST), respectively, detecting nonexchangeable (e.g.

Transient impairment in microglial function causes sex-specific deficits in synaptic maturity and hippocampal function in mice exposed to early adversity.

Abnormal development and function of the hippocampus are two of the most consistent findings in humans and rodents exposed to early-life adversity (ELA), with males often being more affected than females. Using the limited bedding (LB) paradigm as a rodent model of ELA, we found that male adolescent mice that had been exposed to LB exhibit significant deficits in contextual fear conditioning and synaptic connectivity in the hippocampus, which are not observed in females. This is linked to altered developmental refinement of connectivity, with LB severely impairing microglial-mediated synaptic pruning in the hippocampus of male and female pups on postnatal day 17 (P17), but not in adolescent P33 mice when levels of synaptic engulfment by microglia are substantially lower.

mTOR inhibition enhances synaptic and mitochondrial function in Alzheimer's disease in an APOE genotype-dependent manner.

Apolipoprotein ε4 (APOE4) carriers develop brain metabolic dysfunctions decades before the onset of Alzheimer's disease (AD). A goal of the study is to identify if rapamycin, an inhibitor for the mammalian target of rapamycin (mTOR) inhibitor, would enhance synaptic and mitochondrial function in asymptomatic mice with human APOE4 gene (E4FAD) before they showed metabolic deficits. A second goal is to determine whether there may be genetic-dependent responses to rapamycin when compared to mice with human APOE3 alleles (E3FAD), a neutral AD genetic risk factor.

In vivo neuropil density from anatomical MRI and machine learning.

Brain energy budgets specify metabolic costs emerging from underlying mechanisms of cellular and synaptic activities. While current bottom-up energy budgets use prototypical values of cellular density and synaptic density, predicting metabolism from a person's individualized neuropil density would be ideal. We hypothesize that in vivo neuropil density can be derived from magnetic resonance imaging (MRI) data, consisting of longitudinal relaxation (T1) MRI for gray/white matter distinction and diffusion MRI for tissue cellularity (apparent diffusion coefficient, ADC) and axon directionality (fractional anisotropy, FA).

Macro- and microvascular contributions to cerebral structural alterations in patients with asymptomatic carotid artery stenosis.

Atherosclerosis can underly internal carotid artery stenosis (ICAS), a major risk factor for ischemic stroke, as well as small vessel disease (SVD). This study aimed to investigate hemodynamics and structural alterations associated with SVD in ICAS patients. 28 patients with unilateral asymptomatic ICAS and 30 age-matched controls underwent structural (T1-/T2-weighted and diffusion tensor imaging [DTI]) and hemodynamic (pseudo-continuous arterial spin labeling and dynamic susceptibility contrast) magnetic resonance imaging.

High-resolution extracellular pH imaging of liver cancer with multiparametric MR using Deep Image Prior.

Noninvasive extracellular pH (pH) mapping with Biosensor Imaging of Redundant Deviation in Shifts (BIRDS) using MR spectroscopic imaging (MRSI) has been demonstrated on 3T clinical MR scanners at 8  mm spatial resolution and applied to study various liver cancer treatments. Although pH imaging at higher resolution can be achieved by extending the acquisition time, a postprocessing method to increase the resolution is preferable, to minimize the duration spent by the subject in the MR scanner. In this work, we propose to improve the spatial resolution of pH mapping with BIRDS by incorporating anatomical information in the form of multiparametric MRI and using an unsupervised deep-learning technique, Deep Image Prior (DIP).

VEGF-C prophylaxis favors lymphatic drainage and modulates neuroinflammation in a stroke model.

Meningeal lymphatic vessels (MLVs) promote tissue clearance and immune surveillance in the central nervous system (CNS). Vascular endothelial growth factor-C (VEGF-C) regulates MLV development and maintenance and has therapeutic potential for treating neurological disorders. Herein, we investigated the effects of VEGF-C overexpression on brain fluid drainage and ischemic stroke outcomes in mice.

Transmembrane pH gradient imaging in rodent glioma models.

A unique feature of the tumor microenvironment is extracellular acidosis in relation to intracellular milieu. Metabolic reprogramming in tumors results in overproduction of H ions (and lactate), which are extruded from the cells to support tumor survival and progression. As a result, the transmembrane pH gradient (ΔpH), representing the difference between intracellular pH (pH) and extracellular pH (pH), is posited to be larger in tumors compared with normal tissue.

Multimodal measures of spontaneous brain activity reveal both common and divergent patterns of cortical functional organization.

Large-scale functional networks have been characterized in both rodent and human brains, typically by analyzing fMRI-BOLD signals. However, the relationship between fMRI-BOLD and underlying neural activity is complex and incompletely understood, which poses challenges to interpreting network organization obtained using this technique. Additionally, most work has assumed a disjoint functional network organization (i.

Cross-hemicord spinal fiber reorganization associates with cortical sensory and motor network expansion in the rat model of hemicontusion cervical spinal cord injury.

Magnetic resonance imaging plays an important role in characterizing microstructural changes and reorganization after traumatic injuries to the nervous system. In this study, we tested the feasibility of ex-vivo spinal cord diffusion tensor imaging (DTI) in combination with in vivo brain functional MRI to characterize spinal reorganization and its supraspinal association after a hemicontusion cervical spinal cord injury (SCI). DTI parameters (fractional anisotropy [FA], mean diffusion [MD]) and fiber orientation changes related to reorganization in the contused cervical spinal cord were compared to sham specimens.

[WITHDRAWN] Activation of transsulfuration pathway to maintain cysteine is a thermogenic checkpoint for the conservation of energy.

The authors have requested that this preprint be removed from Research Square.