Lesions In Rat Brain Research Articles

Weight-Drop Method for Inducing Closed Head Diffuse Traumatic Brain Injury.

Traumatic brain injury (TBI) is one of the foremost causes of disability and death globally. Prerequisites for successful therapy of disabilities associated with TBI involved improved knowledge of the neurobiology of TBI, measurement of quantitative changes in recovery dynamics brought about by therapy, and the translation of quantitative methodologies and techniques that were successful in tracking recovery in preclinical models to human TBI. Frequently used animal models of TBI in research and development include controlled cortical impact, fluid percussion injury, blast injury, penetrating blast brain injury, and weight-drop impact acceleration models. Preclinical models of TBI benefit from controlled injury settings and the best prospects for biometric quantification of injury and therapy-induced gradual recovery from disabilities. Impact acceleration closed head TBI paradigm causes diffuse TBI (DTBI) without substantial focal brain lesions in rats. DTBI is linked to a significant rate of death, morbidity, and long-term disability. DTBI is difficult to diagnose at the time of hospitalization with imaging techniques making it challenging to take prompt therapeutic action. The weight-drop method without craniotomy is an impact acceleration closed head DTBI model that is used to induce mild/moderate diffuse brain injuries in rodents. Additionally, we have characterized neuropathological and neurobehavioral outcomes of the weight-drop model without craniotomy for inducing closed head DTBI of graded severity with a range of mass of weights (50-450gm). This chapter also discusses techniques and protocols for measuring numerous functional disabilities and pathological changes in the brain brought on by DTBI.

Electroacupuncture ameliorates learning and memory deficits via hippocampal 5-HT1A receptors and the PKA signaling pathway in rats with ischemic stroke.

Hippocampal 5-HT1A receptors and the PKA signaling pathway have been implicated in learning and memory. This study aimed to investigate whether PKA signaling mediated by 5-HT1A receptors was involved in the electroacupuncture (EA)-mediated learning and memory in a rat model of middle cerebral artery occlusion-induced cognitive deficit (MICD). Compared to no treatment or non-acupoint EA treatment, EA at DU20 and DU24 acupoints improved the neurological deficit of scores, shortened escape latency and increased the frequency of crossing the platform in the Morris water maze test. T2-weighted imaging demonstrated that the MICD rat brain lesions were mainly located in the cortex and hippocampus, and injured volumes were reduced after EA. Furthermore, we found that these behavioral changes were concomitant with the deficit of the 5HT1A and PKA signaling pathways in the hippocampus, as the activation of the 5-HT1A receptor, the reduction of PKA kinase activity, and AMPA and NMDA receptor phosphorylation occurred in the injured hippocampus at Day 14 after MICD. Additionally, EA dramatically elevated the activation of PKA. Moreover, EA significantly increased intracellular calcium concentrations regulated by the activation of NMDA receptors. Therefore, PKA kinase and NMDA receptors mediated by 5-HT1A receptors in the hippocampus might contribute to improving learning and memory during the recovery process following ischemic stroke with an EA intervention.

Imaging of the third gasotransmitter hydrogen sulfide using 99mTc-labeled alpha-hydroxy acids

IntroductionHydrogen sulfide (H2S) defined as the third gasotransmitter after nitric oxide (NO) and carbon monoxide (CO) is an important mediator of various physiological functions. Although various H2S-imaging techniques using fluorescence and luminescence have been developed, only one radionuclide imaging using 64Cu-labeled cyclen complex was reported. Thus, we tried to develop 99mTc-labeled H2S imaging agents. MethodsVarious α-hydroxy acids such as glycolate, L-lactate, D-lactate, D-gluconate, D-glucoheptonate, D-glucuronate, D-glucarate, and citrate were labeled with 99mTc in the presence of stannous chloride. The labeled compounds were incubated with 0.2 mM of NaHS, and reactive sulfur species and then analyzed by ITLC/normal saline to detect the formation of insoluble complex. Matrigels containing various concentrations of NaHS were xenografted on the shoulder of normal mice, and an imaging study was performed after intravenous injection of [99mTc]Tc-gluconate. We also obtained autoradiography image of a rat brain with a temporary brain ischemia after intravenous injection of [99mTc]Tc-gluconate. Results[99mTc]Tc-gluconate showed the highest formation of insoluble complex (87.8 ± 3.6%) after incubation with 0.2 mM NaHS. The other reactive species such as glutathione, cysteine, sulfite, sulfate, thiosulfate, and NO did not form insoluble complex representing the reaction being specific to H2S. The Matrigel containing 2 μmol NaHS showed uptake of [99mTc]Tc-gluconate, which proved the feasibility as the specific H2S imaging agent in vivo. Temporary ischemic lesion of rat brain showed high radioactivity accumulation representing the feasibility as endogenous H2S imaging agents. ConclusionWe proved that 99mTc-labeled α-hydroxy acid especially [99mTc]Tc-gluconate is a novel endogenous H2S imaging agent, which might contribute to study and diagnosis of various diseases related with inflammation and hypoxia.

Ischemic damage and early inflammatory infiltration are different in the core and penumbra lesions of rat brain after transient focal cerebral ischemia

Clinical and experimental observations emphasize that inflammation is a direct risk factor for stroke. We performed a detailed histological and immunohistochemical analysis, assisted by digital morphometry, to compare the representative brain lesions in the ischemic core and penumbra in a rat model. Focal neuronal necrosis and degeneration were significantly more intense in the core, whereas inflammatory infiltration, MPO, CD68, CD3, FXIII, Cox-2, iNOS2, Arg-1 expressions were stronger in the penumbra. Our findings indicate that neuroinflammation affects the penumbra more than the core and suggest that targeted modulation of the cellular infiltrate could be exploited to save brain volume.

Celecoxib-induced gastrointestinal, liver and brain lesions in rats, counteraction by BPC 157 or L-arginine, aggravation by L-NAME.

AIMTo counteract/reveal celecoxib-induced toxicity and NO system involvement.METHODSCelecoxib (1 g/kg b.w. ip) was combined with therapy with stable gastric pentadecapeptide BPC 157 (known to inhibit these lesions, 10 μg/kg, 10 ng/kg, or 1 ng/kg ip) and L-arginine (100 mg/kg ip), as well as NOS blockade [N(G)-nitro-L-arginine methyl ester (L-NAME)] (5 mg/kg ip) given alone and/or combined immediately after celecoxib. Gastrointestinal, liver, and brain lesions and liver enzyme serum values in rats were assessed at 24 h and 48 h thereafter.RESULTSThis high-dose celecoxib administration, as a result of NO system dysfunction, led to gastric, liver, and brain lesions and increased liver enzyme serum values. The L-NAME-induced aggravation of the lesions was notable for gastric lesions, while in liver and brain lesions the beneficial effect of L-arginine was blunted. L-arginine counteracted gastric, liver and brain lesions. These findings support the NO system mechanism(s), both NO system agonization (L-arginine) and NO system antagonization (L-NAME), that on the whole are behind all of these COX phenomena. An even more complete antagonization was identified with BPC 157 (at both 24 h and 48 h). A beneficial effect was evident on all the increasingly negative effects of celecoxib and L-NAME application and in all the BPC 157 groups (L-arginine + BPC 157; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157). Thus, these findings demonstrated that BPC 157 may equally counteract both COX-2 inhibition (counteracting the noxious effects of celecoxib on all lesions) and additional NOS blockade (equally counteracting the noxious effects of celecoxib + L-NAME).CONCLUSIONBPC 157 and L-arginine alleviate gastrointestinal, liver and brain lesions, redressing NSAIDs’ post-surgery application and NO system involvement.

Electroacupuncture Regulates Hippocampal Synaptic Plasticity via miR-134-Mediated LIMK1 Function in Rats with Ischemic Stroke.

MircoRNAs (miRs) have been implicated in learning and memory, by regulating LIM domain kinase (LIMK1) to induce synaptic-dendritic plasticity. The study aimed to investigate whether miRNAs/LIMK1 signaling was involved in electroacupuncture- (EA-) mediated synaptic-dendritic plasticity in a rat model of middle cerebral artery occlusion induced cognitive deficit (MICD). Compared to untreatment or non-acupoint-EA treatment, EA at DU20 and DU24 acupoints could shorten escape latency and increase the frequency of crossing platform in Morris water maze test. T2-weighted imaging showed that the MICD rat brain lesions were located in cortex, hippocampus, corpus striatum, and thalamus regions and injured volumes were reduced after EA. Furthermore, we found that the density of dendritic spine and the number of synapses in the hippocampal CA1 pyramidal cells were obviously reduced at Day 14 after MICD. However, synaptic-dendritic loss could be rescued after EA. Moreover, the synaptic-dendritic plasticity was associated with increases of the total LIMK1 and phospho-LIMK1 levels in hippocampal CA1 region, wherein EA decreased the expression of miR-134, negatively regulating LIMK1 to enhance synaptic-dendritic plasticity. Therefore, miR-134-mediated LIMK1 was involved in EA-induced hippocampal synaptic plasticity, which served as a contributor to improving learning and memory during the recovery stage of ischemic stroke.

Expression of aryl hydrocarbon receptor in rat brain lesions following traumatic brain injury.

BackgroundAryl Hydrocarbon Receptor (AhR) is a ligand-activated transcription factor with multiple functions operating in a variety of organs, including the brain. Recent studies have revealed that AhR played a functional role in traumatic injuries. This paper aims to study the expression of AhR during the early phase following a traumatic brain injury (TBI) in rat brains by immunohistochemistry.MethodsWeight-drop induced TBI was performed in rats. The expression of AhR in brain of TBI rats were examined by immunohistochemistry.ResultsNeuron expression of AhR in the rat brains of experiment group had been upregulated since day 3 in lesional hemisphere compared to that of the control group and mainly located in the cytoplasm, indicating an inactivated state. Interestingly, the accumulation of AhR+ non-neuron cells became significant as early as 18 h after injury, which had kept increasing until 24 h post injury and then decreased slowly. For AhR+ non-neuron cells, the AhR mainly located in cell nucleus, indicating a reactive status. Furthermore, double staining showed that most AhR+ non-neuron cells co-localized with W3/13, a marker for T lymphocytes, but not with ED-1 (for activated microglia/macrophages) or GFAP (for activated astrocytes), suggesting that most AhR+ non-neuron cells were T lymphocytes.ConclusionThis is the first study concerning AhR expression in brains following TBI, and our data demonstrated that AhR was upregulated and activated in T lymphocytes following TBI. More research is needed to make a more conclusive conclusion.

Non-Selective Cannabinoid Receptor Antagonists, Hinokiresinols Reduce Infiltration of Microglia/Macrophages into Ischemic Brain Lesions in Rat via Modulating 2-Arachidonolyglycerol-Induced Migration and Mitochondrial Activity.

Growing evidence suggests that therapeutic strategies to modulate the post-ischemic inflammatory responses are promising approaches to improve stroke outcome. Although the endocannabinoid system has been emerged as an endogenous therapeutic target to regulate inflammation after stroke insult, the downstream mechanisms and their potentials for therapeutic intervention remain controversial. Here we identified trans- and cis-hinokiresinols as novel non-selective antagonists for two G-protein-coupled cannabinoid receptors, cannabinoid receptor type 1 and type 2. The Electric Cell-substrate Impedance Sensing and Boyden chamber migration assays using primary microglial cultures revealed that both hinokiresinols significantly inhibited an endocannabinoid, 2-arachidonoylglycerol-induced migration. Hinokiresinols modulated 2-arachidonoylglycerol-induced mitochondrial bioenergetics in microglia as evidenced by inhibition of ATP turnover and reduction in respiratory capacity, thereby resulting in impaired migration activity. In rats subjected to transient middle cerebral artery occlusion (1.5-h) followed by 24-h reperfusion, post-ischemic treatment with hinokiresinols (2 and 7-h after the onset of ischemia, 10 mg/kg) significantly reduced cerebral infarct and infiltration of ED1-positive microglial/macrophage cells into cerebral ischemic lesions in vivo. Co-administration of exogenous 2-AG (1 mg/kg, i.v., single dose at 2 h after starting MCAO) abolished the protective effect of trans-hinokiresionol. These results suggest that hinokiresinols may serve as stroke treatment by targeting the endocannabinoid system. Alteration of mitochondrial bioenergetics and consequent inhibition of inflammatory cells migration may be a novel mechanism underlying anti-ischemic effects conferred by cannabinoid receptor antagonists.

CD200+ and CD200− macrophages accumulated in ischemic lesions of rat brain: The two populations cannot be classified as either M1 or M2 macrophages

Two types of macrophages in lesion core of rat stroke model were identified according to NG2 chondroitin sulfate proteoglycan (NG2) and CD200 expression. NG2(+) macrophages were CD200(-), and vice versa. NG2(-) macrophages expressed two splice variants of CD200 that are CD200L and CD200S. CD200(+) macrophages expressed CD8, CD68, CD163, CCL2, inducible nitric oxide synthase, interleukin-1β, Toll-like receptor 4 and transforming growth factor β, whilst NG2(+) cells expressed a costimulatory factor CD86. Both cell types expressed insulin-like growth factor 1 and CD200R. These results demonstrate that the two macrophage types cannot be classified as either M1 or M2.

Occurrence of Pineal Gland Tumors in Combined Chronic Toxicity/Carcinogenicity Studies in Wistar Rats.

Pineal gland tumors are very rare brain lesions in rats as well as in other species including humans. A total of 8 (out of 1,360 examined) Wistar rats from 3 different combined chronic toxicity/carcinogenicity or mere carcinogenicity studies revealed pineal gland tumors. The tumors were regarded to be spontaneous and unrelated to treatment. The morphology and immunohistochemical evaluation led to the diagnosis malignant pinealoma. The main characteristics that were variably developed within the tumors were the following: cellular atypia, high mitotic index, giant cells, necrosis, Homer Wright rosettes, Flexner-Wintersteiner rosettes and pseudorosettes, positive immunohistochemical reaction for synaptophysin, and neuron-specific enolase. The pineal gland is not a protocol organ for histopathological examination in carcinogenicity studies. Nevertheless, the pineal gland can occasionally be encountered on the routine brain section or if it is the origin of a tumor protruding into the brain, the finding will be recorded. Therefore, although known to be a rare tumor in rats, pineal neoplasms should be included in the list of possible differential diagnoses for brain tumors, especially when the tumor is located in the region of the pineal body.

Bilateral common carotid artery occlusion induced brain lesions in rats: A longitudinal diffusion tensor imaging study

Bilateral common carotid artery occlusion (BCCAO) has been widely used to reproduce the white matter (WM) and gray matter (GM) damage associated with chronic cerebral hypoperfusion (CCH). This study investigated whether diffusion tensor imaging (DTI) could be used at the early stages of disease to assess brain damage induced by BCCAO. To this end, DTI, together with histological methods, was used to evaluate the progression of WM lesions and GM neurodegeneration following BCCAO. The DTI was sufficiently sensitive to detect WM abnormalities in selected regions of the brain at 4weeks after BCCAO. These abnormalities may indicate damage to the myelin and axons in the optic nerve (ON) and optic tract (OT). Our longitudinal results showed that DTI could be used to detect abnormalities of the WM and GM in select regions of the brain as early as 2days after ligation. The DTI parameter patterns of change were region-specific throughout the detection time course. Lesions of the external capsule (EC) and periventricular hypothalamic nucleus (Pe) have not been thoroughly studied before. We found that the EC and Pe were both vulnerable to BCCAO and that the associated lesions could be detected using DTI. The current study demonstrated that in vivo DTI could potentially be used to measure WM damage evolution in a BCCAO rat model as well as early brain injury following CCH.

Application of a compact magnetic resonance imaging system for toxicologic pathology: evaluation of lithium-pilocarpine-induced rat brain lesions.

Magnetic resonance imaging (MRI) is a useful noninvasive tool used to detect lesions in clinical and veterinary medicine. The present study evaluated the suitability of a new easy-to-use compact MRI platform (M2 permanent magnet system, Aspect Imaging, Shoham, Israel) for assisting with preclinical toxicologic pathology examination of lesions in the rat brain. In order to induce brain lesions, male Sprague-Dawley rats were treated once with lithium chloride (127 mg/kg, intraperitoneal [i.p.]) followed by pilocarpine (30 mg/kg, i.p.). One week after dosing, the perfused, fixed brains were collected, analyzed by the MRI system and examined histopathologically. MRI of the brain of treated rats revealed areas of high T1 and middle to low T2 signals, when compared with the controls, in the piriform cortex, lateral thalamic nucleus, posterior paraventricular thalamic nucleus and posterior hypothalamic nucleus of the cerebrum. The altered MRI signal areas were consistent with well-circumscribed foci of neuronal cell degeneration/necrosis accompanied by glial cell proliferation. The present data demonstrated that quick analysis of fixed organs by the MRI system can detect the presence and location of toxicologic lesions and provide useful temporal information for selection of appropriate sections for histopathologic examination before routine slide preparation, especially in complex and functionally heterogeneous organs such as the brain.

Lesions of dorsal striatum eliminate lose‐switch responding but not mixed‐response strategies in rats

We used focal brain lesions in rats to examine how dorsomedial (DMS) and dorsolateral (DLS) regions of the striatum differently contribute to response adaptation driven by the delivery or omission of rewards. Rats performed a binary choice task under two modes: one in which responses were rewarded on half of the trials regardless of choice; and another 'competitive' one in which only unpredictable choices were rewarded. In both modes, control animals were more likely to use a predictable lose-switch strategy than animals with lesions of either DMS or DLS. Animals with lesions of DMS presumably relied more on DLS for behavioural control, and generated repetitive responses in the first mode. These animals then shifted to a random response strategy in the competitive mode, thereby performing better than controls or animals with DLS lesions. Analysis using computational models of reinforcement learning indicated that animals with striatal lesions, particularly of the DLS, had blunted reward sensitivity and less stochasticity in the choice mechanism. These results provide further evidence that the rodent DLS is involved in rapid response adaptation that is more sophisticated than that embodied by the classic notion of habit formation driven by gradual stimulus-response learning.

Protective Effects of Selenium on Cadmium-Induced Brain Damage in Chickens

Selenium (Se) is an important dietary micronutrient with antioxidative roles. Cadmium (Cd), a ubiquitous environmental pollutant, is known to cause brain lesion in rats and humans. However, little is reported about the deleterious effects of subchronic Cd exposure on the brain of poultry and the protective roles on the brain by Se against Cd. The aim of this study was to investigate the protective effects of Se on Cd-induced brain damage in chickens. One hundred twenty 100-day-old chickens were randomly assigned to four groups and were fed a basal diet, or Se (as 10 mg Na2SeO3/kg dry weight of feed), Cd (as 150 mg CdCl2/kg dry weight of feed), or Cd + Se in their basic diets for 60 days. Then, concentrations of Cd and Se, production of nitric oxide (NO), messenger RNA (mRNA) level and activity of inducible NO synthase (iNOS), level of oxidative stress, and histological and ultrastructural changes of the cerebrum and cerebellum were examined. The results showed that Cd exposure significantly increased Cd accumulation, NO production, iNOS activities, iNOS mRNA level, and MDA content in the cerebrum and cerebellum. Cd treatment obviously decreased Se content and antioxidase activities and caused histopathological changes in the cerebrum and cerebellum. Se supplementation during dietary Cd obviously reduced Cd accumulation, NO production, mRNA level and activity of iNOS, oxidative stress, and histopathological damage in the cerebrum and cerebellum of chickens. It indicated that Se ameliorates Cd-induced brain damage in chickens by regulating iNOS-NO system changes, and oxidative stress induced by Cd and Se can serve as a potential therapeutic for Cd-induced brain lesion of chickens.

Astrocytic phosphorylation of PDK1 on Tyr9 following an excitotoxic lesion in the mouse hippocampus

3-phosphoinositide-dependent kinase-1 (PDK1) is suggested to play important roles in the regulation of synaptic plasticity and neuronal cell survival in the mature CNS. Although few studies have investigated the roles of PDK1, little is known about PDK1 changes in glial cells under neuropathological conditions. In current report, phosphorylation of PDK1 was monitored specially on tyrosine residues, following the induction of an excitotoxic lesion in rat brain by using kainic acid administration. In injured hippocampal CA3 region, Tyr9 phosphorylation of PDK1 was increased from 4h until 3 day post-injection. Double immunohistochemistry further evaluated that these phosphorylated forms of PDK1 were localized in astrocytes not other cells. Overexpression of unphosphorylatable mutant, PDK1-Y9F leads to inhibit Protein kinase B (PKB/Akt) activation and cAMP responsive element binding protein (CREB) phosphorylation. In conclusion, our results suggested for the first time that tyrosine phosphorylation of PDK1 is required for PKB and CREB activation in KA-mediated excitotoxic lesion in mouse brain.

Expression of MCP‐1 and fractalkine on endothelial cells and astrocytes may contribute to the invasion and migration of brain macrophages in ischemic rat brain lesions

Some macrophages expressing NG2 chondroitin sulfate proteoglycan (NG2) and the macrophage marker Iba1 accumulate in the ischemic core of a rat brain subjected to transient middle cerebral artery occlusion (MCAO) for 90 min. These cells are termed BINCs (for brain Iba1(+) /NG2(+) cells) and may play a neuroprotective role. Because BINCs are bone marrow-derived cells, they are able to invade ischemic tissue after the onset of an ischemic insult. In this study, chemokine-based mechanisms underlying the invasion of BINCs or their progenitor cells were investigated. We found that isolated BINCs expressed mRNA encoding CCR2 and CX3CR1 at high levels. Cultured astrocytes expressed mRNA encoding their ligands, MCP-1 and fractalkine. Recombinant MCP-1 and/or fractalkine, as well as astrocytes, induced the migration of BINCs in vitro. mRNA for MCP-1, fractalkine, CCR2, and CX3CR1 was expressed in the ischemic core during the acute phase of the ischemic event. Immunohistochemical studies revealed that vascular endothelial cells and astrocytic endfeet expressed MCP-1 and fractalkine, respectively, in the ischemic core during the acute phase. CCR2(+) /Iba1(+) monocytes attached to the inside of the vascular wall at 1 day postreperfusion (dpr), and there were CCR2(+) /CX3CR1(+) macrophage-like cells in the parenchyma in the ischemic lesion core at 2 dpr, which may be the progenitors for BINCs. These results suggest that CCR2(+) monocytes are first attracted to the ischemic lesion by MCP-1(+) endothelial cells and migrate toward fractalkine(+) astrocytic endfeet through the disrupted blood-brain barrier. Thus, chemokines may play a critical role in the accumulation of neuroprotective BINCs. © 2013 Wiley Periodicals, Inc.

Forelimb akinesia and metabolic alteration in the striatum following unilateral 6-hydroxydopamine lesion in rats: An in vivo proton magnetic resonance spectroscopy study

The 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal dopamine system in rat can develop neuropathological and neurochemcial changes similar to those seen in patients with Parkinson’s disease (PD). The purpose of this study was to test the hypothesis that the N-acetylaspartate level (NAA), regarded as neuronal marker would be decreased after 6-OHDA lesions in rat brain and to determine whether metabolic alteration are correlated with behavioral deficit. The animals were undergone adjusting stepping test and proton magnetic resonance spectroscopy (1H-MRS). In vivo 1H-NMR spectra (TR/TE = 2500/144 ms) were acquired from both left (contralateral region) and right striatum (ipsillateral region). There was a highly significant impairment in left forepaw performance and significant reductions in NAA/total creatine (tCr) ratios were observed in the ipsillateral striatum of rat (P < 0.05). Furthermore, there was a significant correlation between left forepaw performance and NAA/tCr level on the whole sample (Spearman correlation test, ρ = 0.634, P = 0.011). Our results suggest that the NAA/tCr ratio may be a valuable criterion for evaluation of functional impairment of the striatum in 6-OHDA rat model of PD.

Subcutaneous injection containing IL-3 and GM-CSF ameliorates stab wound-induced brain injury in rats

Macrophage-like cells densely accumulate in stab wound-induced brain lesions in rats. Many of these cells express the macrophage marker Iba1 and the oligodendrocyte progenitor cell marker NG2 chondroitin sulfate proteoglycan (NG2), and have been termed BINCs (brain Iba1 +/NG2 + cells). Results from our previous study showed that BINCs elicit neuroprotective action, and agents inducing BINC activation or proliferation are expected to ameliorate traumatic brain injuries (TBIs). In the present study, TBI was established by inserting a needle into the cerebrum and moving the needle in a longitudinal, fan-like movement. Isolated BINCs from these stab lesions expressed mRNAs encoding receptors for interleukin-3 (IL-3) and granulocyte/macrophage colony-stimulating factor (GM-CSF). When this mixture of cytokines was added to the cultured BINCs, expression of mRNAs encoding insulin-like growth factor-1, hepatocyte growth factor, and proliferating cell nuclear antigen increased. The cytokine mixture induced enhanced wound healing in BINCs-brain cell co-cultures in vitro. Stab wounds in the rats resulted in significant brain tissue loss at 2 months post-lesion. However, tissue loss was reduced by 40% when the combination of IL-3 and GM-CSF was subcutaneously injected 7 times (once per day) beginning at 2 or 3 days post-lesion (dpl). BINCs are highly proliferative and an intraperitoneal injection of 5-fluorouracil (5FU) at 2 dpl eliminated the BINCs, resulting in death of the rats. The cytokine mixture injection significantly reduced mortality of the 5FU-treated rats. These results suggest that the combination of IL-3 and GM-CSF serves as a promising agent to ameliorate TBI via action on BINCs.

Effects of static magnetic field and cadmium on oxidative stress and DNA damage in rat cortex brain and hippocampus

The present study was undertaken to determine the effect of co-exposure to static magnetic field (SMF) and cadmium (Cd) on the antioxidant enzymes activity and DNA integrity in rat brain. Sub-chronic exposure to CdCl (CdCl(2), 40 mg/L, per os) for 30 days resulted in a significant reduction in antioxidant enzyme activity such as the glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in frontal cortex and hippocampus. Total GSH were decreased in the frontal cortex of the Cd-exposed group. Cd exposure induced an increase in malondialdehyde (MDA) concentration in the frontal cortex and hippocampus. Moreover, the same exposure increased 8-oxo-7,8-dihydro-2-desoxyguanosine (8-oxodGuo) level in rat brain. Interestingly, the combined effect of SMF (128 mT, 1 hour/day for 30 consecutive days) and CdCl (40 mg/L, per os) decreased the SOD activity and glutathione level in frontal cortex as compared with the Cd group. Moreover, the association between SMF and Cd increased MDA concentration in frontal cortex as compared with Cd-exposed rats. DNA analysis revealed that SMF exposure failed to alter 8-oxodGuo concentration in Cd-exposed rats. Our data showed that Cd exposure altered the antioxidant enzymes activity and induced oxidative DNA lesions in rat brain. The combined effect of SMF and Cd increased oxidative damage in rat brain as compared with Cd-exposed rats.

In vivopink-beam imaging and fast alignment procedure for rat brain lesion microbeam radiation therapy

A fast 50 microm-accuracy alignment procedure has been developed for the radiosurgery of brain lesions in rats, using microbeam radiation therapy. In vivo imaging was performed using the pink beam (35-60 keV) produced by the ID17 wiggler at the ESRF opened at 120 mm and filtered. A graphical user interface has been developed in order to define the irradiation field size and to position the target with respect to the skull structures observed in X-ray images. The method proposed here allows tremendous time saving by skipping the swap from white beam to monochromatic beam and vice versa. To validate the concept, the somatosensory cortex or thalamus of GAERS rats were irradiated under several ports using this alignment procedure. The magnetic resonance images acquired after contrast agent injection showed that the irradiations were selectively performed in these two expected brain regions. Image-guided microbeam irradiations have therefore been realised for the first time ever, and, thanks to this new development, the ID17 biomedical beamline provides a major tool allowing brain radiosurgery trials on animal patients.