Rat Head Research Articles

Selective β2-Adrenoceptor Blockade Rescues Mandibular Growth Retardation in Adolescent Rats Exposed to Chronic Intermittent Hypoxia

Activation of the sympathoadrenal system is associated with sleep apnea-related symptoms and metabolic dysfunction induced by chronic intermittent hypoxia (IH). IH can induce hormonal imbalances and growth retardation of the craniofacial bones. However, the relationship between IH and β2-adrenergic receptor signaling in the context of skeletal growth regulation is unclear. This study aimed to investigate the role of β2-adrenergic receptors in IH-induced mandibular growth retardation and bone metabolic alterations. Male 7-week-old Sprague–Dawley rats were subjected to IH for 3 weeks. IH conditions were established using original customized hypoxic chambers; IH was induced at a rate of 20 cycles per hour (oxygen levels changed from 4 to 21% in one cycle) for 8 h per day during the 12 h “lights on” period. The rats received intraperitoneal administration of a β2-adrenergic antagonist (butoxamine) or saline. To exclude dietary effects on general growth, the normoxic rats with saline, normoxic rats with butoxamine, and IH rats with butoxamine were subjected to food restriction to match the body weight gains between IH and other three groups. Body weight, heart rate, blood pressure, and plasma concentrations of leptin, serotonin, and growth hormone were measured. Bone growth and metabolism were evaluated using radiography, microcomputed tomography, and immunohistochemical staining. Plasma leptin levels were significantly increased, whereas that of serotonin and growth hormone were significantly decreased following IH exposure. Leptin levels recovered following butoxamine administration. Butoxamine rescued IH-induced mandibular growth retardation, with alterations in bone mineral density at the condylar head of the mandible. Immunohistochemical analysis revealed significantly lower expression levels of receptor activator of nuclear factor-kappa B ligand (RANKL) in the condylar head of IH-exposed rats. Conversely, recovery of RANKL expression was observed in IH-exposed rats administered with butoxamine. Collectively, our findings suggest that the activation of β2-adrenergic receptors and leptin signaling during growth may be involved in IH-induced skeletal growth retardation of the mandible, which may be mediated by concomitant changes in RANKL expression at the growing condyle.

The effects of the conditioned medium of fetal neural cell culture on the apoptosis in the rat brain after traumatic brain injury

A promising treatment method of the traumatic brain injury (TBI) may be stem cell therapy. However, the question of the nature and mechanisms of action of humoral factors produced by stem cells on apoptotic and reparative processes in the brain after trauma remains open. The purpose of the study was to research the effect of conditioned media of fetal neural cell cultures on the number of apoptotic cells in the cortex and subcortical structures of the rat brain after TBI. Materials and methods. TBI was modelled by dropping a metal cylinder on rat's head. Rat fetuses (E17-18) brain was used to obtain cultures of neural stem/progenitor cells. Conditioned media from cell cultures with high adhesive properties (HA-CM) and low adhesive properties (LA-CM) were used to treat the experimental TBI in rats. The presence of p53-positive cells in the cortex and subcortical structures was investigated by immunohistochemistry. Results. Immunohistochemical analysis of brain sections showed that on the 5th day after TBI in rats there was an increase in the number of p53-positive cells in both the cortex and subcortical structures of the brain. Injection of HA-CM and LA-CM to animals on the 2nd, 3rd, 4th days after TBI was found to reduce the number of p53-positive cells in the cortex, hippocampus and thalamus by approximately half compared to the TBI group. A significant difference in the inhibitory effect of two different conditioned media (HA-CM and LA-CM) on apoptosis in the brain of rats after TBI was not detected. Conclusions. The administration of conditioned media of rat fetal neural cell cultures caused a significant decrease in the number of p53-positive cells in both the cortex and subcortical structures on the 5th day after the brain injury.

Mild blast wave exposure produces intensity-dependent changes in MMP2 expression patches in rat brains – Findings from different blast severities

Matrix metalloproteinase 2 (MMP2) is a gelatinase with multiple functions at the neurovascular interface, including local modification of the glia limitans to facilitate access of immune cells into the brain and amyloid-beta degradation during responses to injury or disease. This study examines regional changes in immunoreactive MMP2 in the rat brain after a single mild (2.7–7.9 psi peak) or moderate (13–17.5 psi peak) blast overpressure (BOP) exposure. Immunopositive MMP2 expression was examined quantitatively in histological sections of decalcified rat heads as a marker at 2, 24, and 72 h after BOP. The MMP2 immunoreactivity was isolated to patchy deposits in brain parenchyma surrounding blood vessels. Separate analyses were conducted for the cerebellum, brain stem caudal to the thalamo-mesencephalic junction, and the cerebrum (including diencephalon). The deposits varied in number, size, staining homogeneity (standard deviation of immunopositive region), and a cumulative measure, the product of size, average intensity and number, as a function of blast intensity and time. The sequences of changes in MMP2 spots from sham control animals suggested that the mild BOP exposure differences normalized within 72 h. However, the responses to moderate exposure revealed a delayed response at 72 h in the subtentorial brain stem and the cerebrum, but not the cerebellum. Hence, local MMP2 responses may be a contextual biomarker for locally regulated responses to widely distributed brain injury foci.

The role of biomechanical forces and MALAT1/miR-329-5p/PRIP signalling on glucocorticoid-induced osteonecrosis of the femoral head.

Glucocorticoid‐induced osteonecrosis of the femoral head (GIONFH) is a common orthopaedic disease. GIONFH primarily manifests clinically as hip pain in the early stages, followed by the collapse of the femoral head, narrowing of the hip joint space and damage to the acetabulum, resulting in severely impaired mobility. However, the pathogenesis of GIONFH is not clearly understood. Recently, biomechanical forces and non‐coding RNAs have been suggested to play important roles in the pathogenesis of GIONFH. This study aimed to evaluate the role of biomechanical forced and non‐coding RNAs in GIONFH. We utilized an in vivo, rat model of GIONFH and used MRI, μCT, GIONFH‐TST (tail suspension test), GIONFH‐treadmill, haematoxylin and eosin staining, qRT‐PCR and Western blot analysis to analyse the roles of biomechanical forces and non‐coding RNAs in GIONFH. We used RAW264.7 cells and MC3T3E1 cells to verify the role of MALAT1/miR‐329‐5p/PRIP signalling using a dual luciferase reporter assay, qRT‐PCR and Western blot analysis. The results demonstrated that MALAT1 and PRIP were up‐regulated in the femoral head tissues of GIONFH rats, RAW264.7 cells, and MC3T3E1 cells exposed to dexamethasone (Dex). Knockdown of MALAT1 decreased PRIP expression in rats and cultured cells and rescued glucocorticoid‐induced osteonecrosis of femoral head in rats. The dual luciferase reporter gene assay revealed a targeting relationship for MALAT1/miR‐329‐5p and miR‐329‐5p/PRIP in MC3T3E1 and RAW264.7 cells. In conclusion, MALAT1 played a vital role in the pathogenesis of GIONFH by binding to (‘sponging’) miR‐329‐5p to up‐regulate PRIP. Also, biomechanical forces aggravated the pathogenesis of GIONFH through MALAT1/miR‐329‐5p/PRIP signalling.

Impact of Extended Access Methamphetamine, Cocaine, and MDPV Self‐administration on Recognition Memory in Rats

Over 18 million people in the United States alone are classified as having an untreated substance use disorder. Given that substance use disorders are chronic by nature, with significant negative impacts on quality of life, it is crucial to gain a better understanding of the consequences of prolonged use in an effort to prevent or reverse deficits in afflicted individuals. Regarding stimulants, monoamine releasers (e.g., methamphetamine) rather than monoamine uptake inhibitors (e.g., cocaine) are associated with greater degrees of neurodegeneration and neuroinflammation, often linked to deficits in memory, psychosis, and loss of impulse control. Interestingly, recent data suggest that MDPV, a synthetic cathinone and monoamine uptake inhibitor, has neurotoxic effects; however, the neurocognitive consequences of MDPV self-administration remain largely unexplored. The current study aimed to directly compare the neurocognitive impacts (deficits in novel object recognition assay [NOR]) in rats (n=8/group) with short- (90-min) or extended- (12-h) access to MDPV (0.032 mg/kg/inf), methamphetamine (0.1 mg/kg/inf), or cocaine (0.32 mg/kg/inf) self-administration; grain pellets were also available throughout the sessions for responding on the alternate lever. Self-administration sessions were conducted five days per week to allow for other behaviors to be evaluated in a drug-free state. NOR was conducted four times, once prior to any drug self-administration history, after 3 and 6 weeks of drug self-administration, and once more following a 3-week drug-free period. To conduct NOR, rats were habituated in the testing arena for 30-min. 24-h later, two identical objects were placed in the arena and rats could explore the objects for 5-min (training). One hour after training, one of the previously explored objects along with a novel object were placed in the arena and rats were allowed to explore the objects for 3-min (testing). Object exploration was defined as the rat's head being within 2 cm of the object without biting it. Rats that had extended access to MDPV or methamphetamine exhibited time-dependent deficits in the novel object recognition assay relative to rats given access to saline. No deficits were observed in rats with extended access to cocaine. Furthermore, rats showed no deficits in recognition memory following short access to any reinforcer. The total exploration time of objects remained comparable among all groups. These data suggest that unlike cocaine, the prototypical monoamine uptake inhibitor, MDPV is capable of producing memory deficits often associated with neuroinflammation and/or neurodegeneration. Future studies will evaluate markers of neurodegeneration and neuroinflammation in these rats and explore pharmacological avenues to mitigate stimulant-induced neurocognitive deficits.

Effect of folinic acid on serum homocysteine, TNFα, IL-10, and HMGB1 gene expression in head injury model

BackgroundHead injury or traumatic brain injury is the leading cause of mortality and morbidity. Many modalities of neuroprotection had been developed in brain injury but there was no much information regarding folinic acid's effect on neuroinflammation associated with homocysteine, TNFα, IL-10, and HMGB1. ObjectiveThis study aimed to investigate whether folinic acid has improving effect on head injury model. MethodThis study was done in the rat's head injury model using modified Marmarou weight drop model. Fifteen rats were randomized and grouped into 3 groups: Group A: Folinic acid (+), head injury (−); Group B: Folinic acid (−), head injury (+); Group C: Folinic acid (+), head injury (+). Folinic acid was administered intraperitoneally with a dose of 60 mg/m2. Blood samples were taken immediately after head injury (H0), 12 h (H12), and 24 h (H24) after head injury from the lateral vein of tail. Serum level of homocysteine, TNFα, and IL-10 were measured using ELISA, and HMGB1 gene expression was measured with Real-Time RT-PCR. ResultsThis study found serum level of homocysteine, TNFα, IL-10 and HMGB1 gene expression were markedly increased at all time points after head injury. Significantly lower level of serum homocysteine, TNFα, IL-10 and HMGB1 gene expression were found after 24 h treatment with folinic acid in group C compared to those in group B. ConclusionFolinic acid may have anti-inflammatory properties in traumatic brain injury by inhibition of serum level of homocysteine, TNFα, IL-10 and HMGB1 gene expression.

Performance Evaluation of SimPET-X, a PET Insert for Simultaneous Mouse Total-Body PET/MR Imaging.

In this study, a small animal PET insert (SimPET-X, Brightonix Imaging Inc.) for simultaneous PET/MR imaging studies is presented. This insert covers an 11-cm-long axial field-of-view (FOV) and enables imaging of mouse total-bodies and rat heads. SimPET-X comprises 16 detector modules to yield a ring diameter of 63 mm and an axial FOV of 110 mm. The detector module supports four detector blocks, each comprising two 4 × 4 SiPM arrays coupled with a 20 × 9 array of LSO crystals (1.2 × 1.2 × 10 mm3). The physical characteristics of SimPET-X were measured in accordance with the NEMA NU4-2008 standard protocol. In addition, we assessed the compatibility of SimPET-X with a small animal-dedicated MRI (M7, Aspect Imaging) and conducted phantom and animal studies. The radial spatial resolutions at the center based on 3D OSEM without and with the warm background were 0.73 mm and 0.99 mm, respectively. The absolute peak sensitivity of the system was 10.44% with an energy window of 100-900 keV and 8.27% with an energy window of 250-750 keV. The peak NECR and scatter fraction for the mouse phantom were 348 kcps at 26.2 MBq and 22.1% with an energy window of 250-750 keV, respectively. The standard deviation of pixel value in the uniform region of an NEMA IQ phantom was 4.57%. The spillover ratios for air- and water-filled chambers were 9.0% and 11.0%, respectively. In the hot-rod phantom image reconstructed using 3D OSEM-PSF, all small rods were resolved owing to the high spatial resolution of the SimPET-X system. There was no notable interference between SimPET-X and M7 MRI. SimPET-X provided high-quality mouse images with superior spatial resolution, sensitivity, and counting rate performance. SimPET-X yielded a remarkably improved sensitivity and NECR compared with SimPETTM.

CircPVT1 up-regulation attenuates steroid-induced osteonecrosis of the femoral head through regulating miR-21-5p-mediated Smad7/TGFβ signalling pathway.

Steroid‐induced osteonecrosis of the femoral head (SIONFH) has been a common disease following corticosteroid therapy. Presently, we aim to explore the functions of circular RNA (circ) PVT1 in SIONFH rats and the underlying mechanism. Glucocorticoid (GC) was used to treat SD rats and bone marrow‐derived mesenchymal stem cells (BMSCs) to construct SIONFH model in vitro and in vivo, respectively. The pathological injury of the femoral head in the SIONFH rats was detected via haematoxylin‐eosin (HE) staining and immunohistochemistry (IHC). The osteogenic differentiation, proliferation and apoptosis of BMSCs were detected. Western blot was used to detect Smad7, Bax, Bcl2 and Smad2/3. The potential targets of circPVT1 and miR‐21‐5p were validated through luciferase reporter gene assay and RNA pull‐down assay, respectively. We found that CircPVT1 was decreased in the femoral head of SIONFH rats and GC‐treated BMSCs, while miR‐21‐5p was markedly up‐regulated. Overexpressed circPVT1 attenuated the apoptosis and cell viability inhibition of BMSCs induced by GC, while miR‐21‐5p up‐regulation had the opposite effects. What's more, the in vivo experiments confirmed that up‐regulating circPVT1 repressed osteonecrosis in SIONFH rats through repressing apoptosis. Mechanistically, circPVT1 functioned as a ceRNA of miR‐21‐5p, which targeted at the 3'untranslated region of Smad7. CircPVT1 enhancing Smad7 and mitigating GC activated TGFβ/Smad2/3 pathway through inhibiting miR‐21‐5p. In conclusion, CircPVT1 exerts protective effects against SIONFH via modulating miR‐21‐5p‐mediated Smad7/TGFβ pathway.

Calycosin modulates inflammation via suppressing TLR4/NF-κB pathway and promotes bone formation to ameliorate glucocorticoid-induced osteonecrosis of the femoral head in rat.

Glucocorticoid (GC) administration is one of the main causes of osteonecrosis of the femoral head (ONFH). Inflammation, especially the TLR4/NF-κB pathway, has been demonstrated to play a pivotal role in the pathogenesis of GC-induced ONFH. Calycosin, the main bioactive extract of Astragali Radix, could substantially regulate the TLR4/NF-κB pathway. Therefore, in this study, we hypothesized that calycosin could exert beneficial effects in GC-induced ONFH. In vitro, effects of calycosin on the osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs) were determined using Alizarin red staining, alkaline phosphatase activity examination, and osteogenic-related gene assay. Meanwhile, inflammatory cytokines were detected by enzyme-linked immunosorbent assay. In vivo, 60 male Sprague-Dawley rats were randomly separated into three groups: the control group, the methylprednisolone (MPS) group, and the MPS + calycosin group. The results showed that calycosin could significantly promote dynamic bone formation and retard TLR4/NF-κB pathway. in vivo investigations indicated that calycosin could decrease the morbidity of ONFH and alleviate pathological manifestations within the femoral head. Meanwhile, calycosin could protect osseous blood supply and facilitate dynamic bone formation. The findings collectively demonstrated that calycosin could ameliorate GC-induced ONFH in rat and might become a potential candidate for pharmaceutical prevention of this intractable disease.

Irradiation of the head reduces adult hippocampal neurogenesis and impairs spatial memory, but leaves overall health intact in rats.

Treatment of brain cancer, glioma, can cause cognitive impairment as a side-effect, possibly because it disrupts the integrity of the hippocampus, a structure vital for normal memory. Radiotherapy is commonly used to treat glioma, but the effects of irradiation on the brain are still poorly understood, and other biological effects have not been extensively studied. Here, we exposed healthy adult male rats to moderate-dose irradiation of the head. We found no effect of irradiation on systemic inflammation, weight gain or gut microbiota diversity, although it increased the abundance of Bacteroidaceae family, namely Bacteroides genus in the gut microbiota. Irradiation had no effect on long-term potentiation in the CA3-CA1 synapse or endogenous hippocampal electrophysiology, but it did reduce adult hippocampal neurogenesis and impaired short-term spatial recognition memory. However, no overall cognitive impairment was observed. To summarize, our results suggest that in adult male rats head irradiation does not compromise health or cognition overall even though the number of new, adult-born hippocampal neurons is decreased. Thus, the sole effects of head irradiation on the body, brain and cognition might be less harmful than previously thought, and the cognitive decline experienced by cancer patients might originate from physiological and mental effects of the disease itself. Therefore, to increase the translational value of animal studies, the effects of irradiation should be studied together with cancer, in older animals, using varying irradiation protocols and doses.

Original experimental rat model of blast-induced mild traumatic brain injury: a pilot study

ABSTRACT Objective Diagnosing blast-induced mild traumatic brain injury (mTBI) is difficult due to minimal imaging findings. This study aimed to establish a rat model of behavioral abnormality caused by blast-induced mTBI and detect new findings for therapeutic intervention. Methods We used a bench-top blast wave generator with the blast wave exiting through a 20-mm I.D. nozzle aimed at the focused target. The blast wave was directed at the head of male Wistar rats under general anesthesia positioned prone 2.5 cm below the nozzle. Peak shock wave pressure was 646.2 ± 70.3 kPa. Results After blast injury, mTBI rats did not show the findings of brain hemorrhage or contusion macroscopically and on hematoxylin-eosin-stained frozen sections but did show anorexia and weight loss in the early post-injury phase. Behavioral experiments revealed short-term memory impairment at 2 weeks and depression-like behavior at 2 and 6 weeks. Diffusion-weighted ex vivo MRI showed high-intensity areas in layers of the bilateral hippocampus. Immunohistochemical analysis revealed accumulation of reactive microglia and GFAP-positive astrocytes in the same region and loss of NeuN-positive neurons in the hippocampal pyramidal cell layer. Conclusions This model can reflect the pathophysiology of blast-induced mTBI and could potentially be used to develop therapeutic interventions in the future.

Diş Dolgu Materyallerinin Karaciğer ve Böbrek Dokuları Üzerine Olan Zararlı Etkileri

The purpose of this study was to examine the potential effects of restorative dental materials on the kidneys and liver tissues of rats. The histological, immunohistochemical and biochemical analyzes were conducted using 32 adult female Wistar albino rats classified into 4 groups (n=8): Control group, Dental amalgam group, Resin composite group, and Glass-ionomer group. The dental materials mentioned were put on the backs of the rat heads and kept there for 8 weeks. After humanely euthanizing rats, kidney and liver tissue was removed by necropsy, and Hematoxylin&Eosin and NF-κB p65 staining methods were used. In addition, glutathione, superoxide dismutase, lipid peroxidation and catalase levels have been identified. Immune-positive cells were higher in all sample groups than in the control group. Renal and hepatic degeneration has also been found in dental filling content groups. All biochemical findings revealed oxidative stress in all groups with the exception for control group. The three dental filling products have significant cytotoxic effects on the kidney and liver tissues, and may have been linked with oxidative stress in the tissues of the kidney and liver.

Continuous Whole-Body 3D Kinematic Recordings across the Rodent Behavioral Repertoire

In mammalian animal models, high-resolution kinematic tracking is restricted to brief sessions in constrained environments, limiting our ability to probe naturalistic behaviors and their neural underpinnings. To address this, we developed CAPTURE (Continuous Appendicular and Postural Tracking Using Retroreflector Embedding), a behavioral monitoring system that combines motion capture and deep learning to continuously track the 3D kinematics of a rat's head, trunk, and limbs for week-long timescales in freely behaving animals. CAPTURE realizes 10- to 100-fold gains in precision and robustness compared with existing convolutional network approaches to behavioral tracking. We demonstrate CAPTURE's ability to comprehensively profile the kinematics and sequential organization of natural rodent behavior, its variation across individuals, and its perturbation by drugs and disease, including identifying perseverative grooming states in a rat model of fragile X syndrome. CAPTURE significantly expands the range of behaviors and contexts that can be quantitatively investigated, opening the door to a new understanding of natural behavior and its neural basis.

Phosphodiesterase-5 inhibition improves bone regeneration at the early stages of ischemic osteonecrosis of the femoral head in rats.

Posttraumatic osteonecrosis of the femoral head (ONFH) affects patients at different ages and may lead to functional limitation and joint replacement, with total hip arthroplasty, which is a costly procedure. Proposed methods to optimize ischemic tissue regeneration have been reported. Phosphodiesterase-5 inhibitors act by inhibiting the degradation of guanosine 3',5'-cyclic monophosphate in the nitric oxide pathway, increasing its bioavailability and promoting vascular endothelial growth factor (VEGF)-mediated neovascular recruitment and the induction of tissue regeneration in the traumatized bone. Thirty male Sprague-Dawley rats (6 months old) were subjected to an experimental model of traumatic ONFH divided into two groups, according to the administration of 5 mg/kg sildenafil or water (control group). Rats were then killed at 7, 14, and 21 days. Histological (Goldner's trichrome), histochemical (periodic acid-Schiff [PAS]), and immunohistochemical (VEGF and osteopontin [OPN]) techniques were used to quantify bone and vascular responses. Higher levels of VEGF (p < 0.01) and OPN (p < 0.01) immunostaining in the epiphysis, the greater formation of osteoid tissue (p < 0.01 on Day 7; p < 0.05 on Day 14), and higher levels of PAS staining (p < 0.01 on Day 7) were observed in the sildenafil-treated group. The present study demonstrated that sildenafil optimized bone tissue regeneration by increasing VEGF signaling and OPN expression, with increased bone formation (osteoid and carbohydrate macromolecule deposition) in the early stages following traumatic ischemic insult. Thus, sildenafil treatment may improve the prognosis of patients with osteonecrosis.

Phase unwrapping with a rapid opensource minimum spanning tree algorithm (ROMEO).

PurposeTo develop a rapid and accurate MRI phase‐unwrapping technique for challenging phase topographies encountered at high magnetic fields, around metal implants, or postoperative cavities, which is sufficiently fast to be applied to large‐group studies including Quantitative Susceptibility Mapping and functional MRI (with phase‐based distortion correction).MethodsThe proposed path‐following phase‐unwrapping algorithm, ROMEO, estimates the coherence of the signal both in space—using MRI magnitude and phase information—and over time, assuming approximately linear temporal phase evolution. This information is combined to form a quality map that guides the unwrapping along a 3D path through the object using a computationally efficient minimum spanning tree algorithm. ROMEO was tested against the two most commonly used exact phase‐unwrapping methods, PRELUDE and BEST PATH, in simulated topographies and at several field strengths: in 3T and 7T in vivo human head images and 9.4T ex vivo rat head images.ResultsROMEO was more reliable than PRELUDE and BEST PATH, yielding unwrapping results with excellent temporal stability for multi‐echo or multi‐time‐point data. It does not require image masking and delivers results within seconds, even in large, highly wrapped multi‐echo data sets (eg, 9 seconds for a 7T head data set with 31 echoes and a 208 × 208 × 96 matrix size).ConclusionOverall, ROMEO was both faster and more accurate than PRELUDE and BEST PATH, delivering exact results within seconds, which is well below typical image acquisition times, enabling potential on‐console application.

Administration of mircoRNA-135b-reinforced exosomes derived from MSCs ameliorates glucocorticoid-induced osteonecrosis of femoral head (ONFH) in rats.

Exosomes were found to exert a therapeutic effect in the treatment of osteonecrosis of the femoral head (ONFH), while miR‐135b was shown to play an important role in the development of ONFH. In this study, we investigated the effects of concomitant administration of exosomes and miR‐135b on the treatment of ONFH. A rat mode of ONFH was established. TEM, Western blotting and nanoparticle analysis were used to characterize the exosomes collected from human‐induced pluripotent stem cell–derived mesenchymal stem cells (hiPS‐MSC‐Exos). Micro‐CT was used to observe the trabecular bone structure of the femoral head. Real‐time PCR, Western blot analysis, IHC assay, TUNEL assay, MTT assay and flow cytometry were performed to detect the effect of hiPS‐MSC‐Exos and miR‐135b on cell apoptosis and the expression of PDCD4/caspase‐3/OCN. Moreover, computational analysis and luciferase assay were conducted to identify the regulatory relationship between PDCD4 mRNA and miR‐135b. The hiPS‐MSC‐Exos collected in this study displayed a spheroidal morphology with sizes ranging from 20 to 100 nm and a mean concentration of 1 × 1012 particles/mL. During the treatment of ONFH, the administration of hiPS‐MSC‐Exos and miR‐135b alleviated the magnitude of bone loss. Furthermore, the treatment of MG‐63 and U‐2 cells with hiPS‐MSC‐Exos and miR‐135b could promote cell proliferation and inhibit cell apoptosis. Moreover, PDCD4 mRNA was identified as a virtual target gene of miR‐135b. HiPS‐MSC‐Exos exerted positive effects during the treatment of ONFH, and the administration of miR‐135b could reinforce the effect of hiPS‐MSC‐Exos by inhibiting the expression of PDCD4.

Effect of Heavy Ion 12C6+ Radiation on Lipid Constitution in the Rat Brain.

Heavy ions refer to charged particles with a mass greater than four (i.e., alpha particles). The heavy ion irradiation used in radiotherapy or that astronauts suffer in space flight missions induces toxicity in normal tissue and leads to short-term and long-term damage in both the structure and function of the brain. However, the underlying molecular alterations caused by heavy ion radiation have yet to be completely elucidated. Herein, untargeted and targeted lipidomic profiling of the whole brain tissue and blood plasma 7 days after the administration of the 15 Gy (260 MeV, low linear energy (LET) = 13.9 KeV/μm) plateau irradiation of disposable 12C6+ heavy ions on the whole heads of rats was explored to study the lipid damage induced by heavy ion radiation in the rat brain using ultra performance liquid chromatography-mass spectrometry (UPLC–MS) technology. Combined with multivariate variables and univariate data analysis methods, our results indicated that an orthogonal partial least squares discriminant analysis (OPLS–DA) could clearly distinguish lipid metabolites between the irradiated and control groups. Through the combination of variable weight value (VIP), variation multiple (FC), and differential (p) analyses, the significant differential lipids diacylglycerols (DAGs) were screened out. Further quantitative targeted lipidomic analyses of these DAGs in the rat brain tissue and plasma supported the notion that DAG 47:1 could be used as a potential biomarker to study brain injury induced by heavy ion irradiation.

Cortico-Striatal Oscillations Are Correlated to Motor Activity Levels in Both Physiological and Parkinsonian Conditions.

Oscillatory neural activity in the cortico-basal ganglia-thalamocortical (CBGTC) loop is associated with the motor state of a subject, but also with the availability of modulatory neurotransmitters. For example, increased low-frequency oscillations in Parkinson’s disease (PD) are related to decreased levels of dopamine and have been proposed as biomarkers to adapt and optimize therapeutic interventions, such as deep brain stimulation. Using neural oscillations as biomarkers require differentiating between changes in oscillatory patterns associated with parkinsonism vs. those related to a subject’s motor state. To address this point, we studied the correlation between neural oscillatory activity in the motor cortex and striatum and varying degrees of motor activity under normal and parkinsonian conditions. Using rats with bilateral or unilateral 6-hydroxydopamine lesions as PD models, we correlated the motion index (MI)—a measure based on the physical acceleration of the head of rats—to the local field potential (LFP) oscillatory power in the 1–80 Hz range. In motor cortices and striata, we observed a robust correlation between the motion index and the oscillatory power in two main broad frequency ranges: a low-frequency range [5.0–26.5 Hz] was negatively correlated to motor activity, whereas a high-frequency range [35.0–79.9 Hz] was positively correlated. We observed these correlations in both normal and parkinsonian conditions. In addition to these general changes in broad-band power, we observed a more restricted narrow-band oscillation [25–40 Hz] in dopamine-denervated hemispheres. This oscillation, which seems to be selective to the parkinsonian state, showed a linear frequency dependence on the concurrent motor activity level. We conclude that, independently of the parkinsonian condition, changes in broad-band oscillatory activities of cortico-basal ganglia networks (including changes in the relative power of low- and high-frequency bands) are closely correlated to ongoing motions, most likely reflecting he operations of these neural circuits to control motor activity. Hence, biomarkers based on neural oscillations should focus on specific features, such as narrow frequency bands, to allow differentiation between parkinsonian states and physiological movement-dependent circuit modulation.

CHANGES IN THE CONTENT OF IMMUNE CELLS CONTAINING THE FcR III RECEPTOR IN THE SLEEP AND BRAIN AFTER EXPERIMENTAL TBI

At TBI there are disturbances in activity of immune system, can complicate regenerative and reparative responses in a brain. The aim of the study was to study the content of CD-16 cells in the spleen and brain parenchyma at different times after TBI in rats and in the correction of disorders in their composition by immunomodulatory drug galalite.Methods. Craniocerebral trauma in animals was modeled by dropping a load weighing 100 g from a height of 120 cm on the head of rats that were anesthetized and were in a state of narcotic sleep, which lasted up to 30 minutes. To correct the resulting disorders used immunomodulatory drug galavit at a dose of 2 mg / kg of animal weight in a volume of0.5 ml, which was administered intramuscularly to animals for 2, 3, 4 days after injury. The spleen and the left and right hemispheres of the brain were homogenized in 5.0 ml of medium 199 and suspensions containing 10.0x106 cells per 1 ml of medium 199 microglia were prepared and infiltrated CNS monocytes were prepared by the method of Sedgwick J. in co-authors. Determination of the level of CD-16 cells in suspensions of spleen and microglia was performed on a flow cytometer using monoclonal antibodies against CD-16 receptor company BD Biosciences according to the instructions for antibodies.Results. In mild TBI in rats, the number of CD- 16 cells containing the FcR III receptor decreases in the spleen for 2 to 5 days, and the number of these cells in the fractions of microglial cells increases. Galavit is a drug with immunomodulatory properties, has virtually no effect on low levels of CD-16 cells in the spleen and stimulates their accumulation in the brain for 10 days after TBI.Conclusions. The results indicate the effect of Galavit on the level of CD-16 cells in the spleen and brain, which indicates the immunomodulatory activity of this drug.

High frequency electrical field-ultrashort wave therapy for treatment of cerebral ischemia/reperfusion injury in rats*: Histopathological evaluation

Abstract BACKGROUND Ultrashortwave (USW) therapy may be a new method for treatment of ischemic cerebrovascular diseases. It is necessary to study its treatment time window. OBJECTIVE To observe the effect of USW on reperfusion injury after occlusion of the middle cerebral artery (MCAO) in rats and discuss its acting mechanisms and best occasion. DESIGN Randomized controlled observation, animal experiment. SETTING Laboratory of Department of Rehabilitation Medicine, First Hospital Affiliated to China Medical University. MATERIALS Sixty-six healthy Wistar rats of either gender and of clean grade, aged 18 – 20 weeks, weighing from 250 to 300 g, were provided by the Experimental Animal Center of China Medical University. An USW device (Shanghai Electrical Device Company) with the frequency of 40.68 MHz and the maximum output power of 40 W, and the first channel power controlled at about 11 W was used in this study. Output power was determined by photometry. METHODS Sixty-six rats were randomly divided into 3 groups: Sham-operation group (n = 6): The suture was inserted only 1.0 depth during operation, which did not cause MACO; Model group (n = 12): The USW treatment procedure was performed with the power off on the model rats; USW treatment group (n = 48): The 48 rats were randomly divided into modeling 0, 6, 12 and 18 hours 4 subgroups. USW therapy without heat was used on the head of rats for 10 minutes at each time point. Twelve rats in USW treatment group were decapitated following treatment at each time point, and then their brain tissues were harvested. The rat brain tissues in other groups were harvested by decapitation at 24 hours after modeling. When the rats were awake, the neurologic deficit was scored by Zea-Longa five-point scale (a score of 0 indicated no neurologic deficit, a score of 1 indicated failure to extend left paw fully, a score of 2 indicated circling to the left, and a score of 3 indicated falling to the left, and rats with a score of 4 did not walk spontaneously and has a depressed level of consciousness.) Rats which still survived at 24 hours and was scored 1 and 2 on the neurologic scoring were involved in the analysis. (1) Determination of cerebral water content: Cerebral water contents of healthy and injured hemisphere were determined by wet/dry weighing method. Cerebral water content (100%) = (1 – dry/wet weight) × 100%. (2)Infarction volume: The brain tissue was sliced into 2 mm sections and each section was stained with 20 g/L 2,3,5-triphenyltetrazolium chloride (TTC) by TTC staining technique for 30 minutes in a water bath at 37 °C. Then, the section was fixed in 100 g/L formaldehyde for 10 minutes. The infarction volume was analyzed by using an imaging analyzer. (3) Preparation of light microscopic sample: The rat brain tissue fixed by 100 g/L neutral formaldehyde and stained with TTC, were gradiently dehydrated with alcoholic, embedded with paraffin, sliced and stained by HE, finally, the sections were observed under the light microscope. MAIN OUTCOME MEASURES Cerebral water content, cerebral infarction volume and cerebral histomorphology of rats in each group. RESULTS Sixty-six rats were involved in the final analysis. (1) Cerebral water content: There were no significant differences of cerebral water content in healthy hemisphere among groups (P > 0.05). Cerebral water content of injured hemisphere in the model group and at modeling 0, 6, 12 and 18 hours in the USW treatment group was (81.50±0.74) %, (81.02±0.83) %, (79.78±0.70) %, (79.74±0.84) %, (79.39±1.06) %, respectively, which was significantly higher than that in the sham-operation group [(78.09±0.52) %, P CONCLUSION USW may play a protective effect on cerebral ischemia/reperfusion injury by decreasing brain edema and/or cerebral infarction volume. The treatment action of USW may start at 6 hours after reperfusion, and the best occasion of application may be at 18 hours after reperfusion.