ischemic brain injury in neonatal rats

African Journals Online (AJOL)

Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, ... Methods: Forty-eight rats (P7-pups) were randomly assigned to one of four groups: ... Keywords: Hypoxic–ischemic brain injury, α-Lipoic acid, Cerebral infarct area, Edema, Antioxidants, .... Of the 48 rats initially used in the current study, 5.

Effect of hyperbaric oxygen on lipid peroxidation and visual development in neonatal rats with hypoxia-ischemia brain damage.

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Chen, Jing; Chen, Yan-Hui; Lv, Hong-Yan; Chen, Li-Ting

2016-07-01

The aim of the present study was to investigate the effect of hyperbaric oxygen (HBO) on lipid peroxidation and visual development in a neonatal rat model of hypoxic-ischemic brain damage (HIBD). The rat models of HIBD were established by delayed uterus dissection and were divided randomly into two groups (10 rats each): HIBD and HBO-treated HIBD (HIBD+HBO) group. Another 20 rats that underwent sham-surgery were also divided randomly into the HBO-treated and control groups. The rats that underwent HBO treatment received HBO (0.02 MPa, 1 h/day) 24 h after the surgery and this continued for 14 days. When rats were 4 weeks old, their flash visual evoked potentials (F-VEPs) were monitored and the ultrastructures of the hippocampus were observed under transmission electron microscope. The levels of superoxide dismutase (SOD) and malonyldialdehyde (MDA) in the brain tissue homogenate were detected by xanthine oxidase and the thiobarbituric acid colorimetric method. Compared with the control group, the ultrastructures of the pyramidal neurons in the hippocampal CA3 area were distorted, the latencies of F-VEPs were prolonged (P0.05). HBO enhances antioxidant capacity and reduces the ultrastructural damage induced by hypoxic-ischemia, which may improve synaptic reconstruction and alleviate immature brain damage to promote the habilitation of brain function.

Influence of intracerebral exposure to enriched uranium on neutron specific enolase and interleukin-1 β content in neonatal rats

International Nuclear Information System (INIS)

Gu Guixiong; Zhu Shoupeng; Wang Liuyi; Yang Shuqin; Zhu Lingli

2001-01-01

Objective: To examine biochemically the injurious effects of enriched uranium 235 U on developing brain of neonatal rats. Methods: Neonatal rats were irradiated with single injection of 2 μl enriched uranium into the left lateral ventricle of the brain at postnatal day 1 ( 235 U, respectively. The micro-autoradiographic tracing was performed, somatic growth and neuro-behavior development of neonatal rats were examined by determination of multiple parameters, and the neuron specific enolase (NSE) and interleukin-1 β(IL-1 β) levels in brains were determined with radioimmunoassay. Results: The radionuclides were mainly accumulated in the neuronal nucleus, and autoradiographic tracks appeared in the cytoplasm and inter- cellular space. Neonatal rats showed delayed growth and abnormal neuro-behavior. The changes of NSE, IL-1 β in cerebellum, cerebral cortex, hippocampus, diencephalons showed a dose-dependent relationship that when the dose of irradiation was increased, the levels of NSE was decreased and the IL-1 β was increased. Conclusion: The nerve cell of developing brain of neonatal rats is sensitive, fragile and compensable to injurious effects of α-irradiation from enriched uranium

Studies on cerebral protection of digoxin against hypoxic-ischemic brain damage in neonatal rats.

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Peng, Kaiwei; Tan, Danfeng; He, Miao; Guo, Dandan; Huang, Juan; Wang, Xia; Liu, Chentao; Zheng, Xiangrong

2016-08-17

Hypoxic-ischemic brain damage (HIBD) is a major cause of neonatal acute deaths and chronic nervous system damage. Our present study was designed to investigate the possible neuroprotective effect of digoxin-induced pharmacological preconditioning after hypoxia-ischemia and underlying mechanisms. Neonatal rats were assigned randomly to control, HIBD, or HIBD+digoxin groups. Pharmacological preconditioning was induced by administration of digoxin 72 h before inducing HIBD by carotid occlusion+hypoxia. Behavioral assays, and neuropathological and apoptotic assessments were performed to examine the effects; the expression of Na/K ATPase was also assessed. Rats in the HIBD group showed deficiencies on the T-maze, radial water maze, and postural reflex tests, whereas the HIBD+digoxin group showed significant improvements on all behavioral tests. The rats treated with digoxin showed recovery of pathological conditions, increased number of neural cells and proliferative cells, and decreased number of apoptotic cells. Meanwhile, an increased expression level of Na/K ATPase was observed after digoxin preconditioning treatment. The preconditioning treatment of digoxin contributed toward an improved functional recovery and exerted a marked neuroprotective effect including promotion of cell proliferation and reduction of apoptosis after HIBD, and the neuroprotective action was likely associated with increased expression of Na/K ATPase.

Influence of neonatal and adult hyperthyroidism on behavior and biosynthetic capacity for norepinephrine, dopamine and 5-hydroxytryptamine in rat brain.

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Rastogi, R B; Singhal, R L

1976-09-01

In neonatal rats, administration of l-triiodothyronine (10 mug/100 g/day) for 30 days presented signs of hyperthyroidism which included accelerated development of a variety of physical and behavioral characteristics accompanying maturation. The spontaneous motor activity was increased by 69%. Exposure of developing rats to thyroid hormone significantly increased the endogenous concentration of striatal tyrosine and the activity of tyrosine hydroxylase as well as the levels of dopamine in several brain regions. The concentration of striatal homovanillic acid and 3,4-dihydroxyphenylacetic acid, the chief metabolites of dopamine, was also increased and the magnitude of change was greater than the rise in dopamine. Despite increases in the activity of tyrosine hydroxylase and the availability of the substrate tyrosine, the steady-state levels of norepinephrine remained unaltered in various regions of brain except in cerebellum. Futhermore, neonatal hyperthyroidism significantly increased the levels of midbrain tryptophan and tryptophan hydroxylase activity but produced no change in 5-hydroxytryptamine levels of several discrete brain regions, except hypothalamus and cerebellum where its concentration was slightly decreased. However, the 5-hydroxyindoleacetic acid levels were enhanced in hypothalamus, ponsmedulla, midbrain, striatum and hippocampus. The elevated levels of 5-hydroxyindoleacetic acid did not seem to be due to increased intraneuronal deamination of 5-hydroxytryptamine since monoamine oxidase activity was not affected in cerebral cortex and midbrain of hyperthyroid rats. The data demonstrate that hyperthyroidism significantly increased the synthesis as well as the utilization of catecholamines and 5-hydroxytryptamine in maturing brain. Since the mature brain is known to respond differently to thyroid hormone action than does the developing brain, the effect of L-triiodothyronine treatment on various putative neurohumors also was examined in adult rats

Neuroprotection of lamotrigine on hypoxic-ischemic brain damage in neonatal rats: Relations to administration time and doses

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Yong-Hong Yi

2008-06-01

Full Text Available Yong-Hong Yi1, Wen-Chao Guo1, Wei-Wen Sun1, Tao Su1, Han Lin1, Sheng-Qiang Chen1, Wen-Yi Deng1, Wei Zhou2, Wei-Ping Liao11Department of Neurology, Institute of Neurosciences and the Second Affiliated Hospital, 2Department of Neonatology, Affiliated Guangzhou Children’s Hospital, Guangzhou Medical College, Guangzhou, Guangdong Province, P.R. ChinaAbstract: Lamotrigine (LTG, an antiepileptic drug, has been shown to be able to improve cerebral ischemic damage by limiting the presynaptic release of glutamate. The present study investigated further the neuroprotective effect of LTG on hypoxic-ischemic brain damage (HIBD in neonatal rats and its relations to administration time and doses. The HIBD model was produced in 7-days old SD rats by left common carotid artery ligation followed by 2 h hypoxic exposure (8% oxygen. LTG was administered intraperitoneally with the doses of 5, 10, 20, and 40 mg/kg 3 h after operation and the dose of 20 mg/kg 1 h before and 3 h, 6 h after operation. Blood and brain were sampled 24 h after operation. Nissl staining, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL, and neuron-specific enolase (NSE immunohistochemical staining were used for morphological studies. Water content in left cortex and NSE concentration in serum were determined. LTG significantly reduced water content in the cerebral cortex, as well as the number of TUNEL staining neurons in the dentate gyrus and cortex in hypoxic-ischemia (HI model. Furthermore, LTG significantly decreased the NSE level in serum and increased the number of NSE staining neurons in the cortex. These effects, except that on water content, were dose-dependent and were more remarkable in the pre-treated group than in the post-treated groups. These results demonstrate that LTG may have a neuroprotective effect on acute HIBD in neonates. The effect is more prominent when administrated with higher doses and before HI.Keywords: hypoxic-ischemic brain

Neuroprotection by Caffeine in Hyperoxia-Induced Neonatal Brain Injury

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Stefanie Endesfelder

2017-01-01

Full Text Available Sequelae of prematurity triggered by oxidative stress and free radical-mediated tissue damage have coined the term “oxygen radical disease of prematurity”. Caffeine, a potent free radical scavenger and adenosine receptor antagonist, reduces rates of brain damage in preterm infants. In the present study, we investigated the effects of caffeine on oxidative stress markers, anti-oxidative response, inflammation, redox-sensitive transcription factors, apoptosis, and extracellular matrix following the induction of hyperoxia in neonatal rats. The brain of a rat pups at postnatal Day 6 (P6 corresponds to that of a human fetal brain at 28–32 weeks gestation and the neonatal rat is an ideal model in which to investigate effects of oxidative stress and neuroprotection of caffeine on the developing brain. Six-day-old Wistar rats were pre-treated with caffeine and exposed to 80% oxygen for 24 and 48 h. Caffeine reduced oxidative stress marker (heme oxygenase-1, lipid peroxidation, hydrogen peroxide, and glutamate-cysteine ligase catalytic subunit (GCLC, promoted anti-oxidative response (superoxide dismutase, peroxiredoxin 1, and sulfiredoxin 1, down-regulated pro-inflammatory cytokines, modulated redox-sensitive transcription factor expression (Nrf2/Keap1, and NFκB, reduced pro-apoptotic effectors (poly (ADP-ribose polymerase-1 (PARP-1, apoptosis inducing factor (AIF, and caspase-3, and diminished extracellular matrix degeneration (matrix metalloproteinases (MMP 2, and inhibitor of metalloproteinase (TIMP 1/2. Our study affirms that caffeine is a pleiotropic neuroprotective drug in the developing brain due to its anti-oxidant, anti-inflammatory, and anti-apoptotic properties.

Cerebral microbleeds in a neonatal rat model.

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Brianna Carusillo Theriault

Full Text Available In adult humans, cerebral microbleeds play important roles in neurodegenerative diseases but in neonates, the consequences of cerebral microbleeds are unknown. In rats, a single pro-angiogenic stimulus in utero predisposes to cerebral microbleeds after birth at term, a time when late oligodendrocyte progenitors (pre-oligodendrocytes dominate in the rat brain. We hypothesized that two independent pro-angiogenic stimuli in utero would be associated with a high likelihood of perinatal microbleeds that would be severely damaging to white matter.Pregnant Wistar rats were subjected to intrauterine ischemia (IUI and low-dose maternal lipopolysaccharide (mLPS at embryonic day (E 19. Pups were born vaginally or abdominally at E21-22. Brains were evaluated for angiogenic markers, microhemorrhages, myelination and axonal development. Neurological function was assessed out to 6 weeks.mRNA (Vegf, Cd31, Mmp2, Mmp9, Timp1, Timp2 and protein (CD31, MMP2, MMP9 for angiogenic markers, in situ proteolytic activity, and collagen IV immunoreactivity were altered, consistent with an angiogenic response. Vaginally delivered pups exposed to prenatal IUI+mLPS had spontaneous cerebral microbleeds, abnormal neurological function, and dysmorphic, hypomyelinated white matter and axonopathy. Pups exposed to the same pro-angiogenic stimuli in utero but delivered abdominally had minimal cerebral microbleeds, preserved myelination and axonal development, and neurological function similar to naïve controls.In rats, pro-angiogenic stimuli in utero can predispose to vascular fragility and lead to cerebral microbleeds. The study of microbleeds in the neonatal rat brain at full gestation may give insights into the consequences of microbleeds in human preterm infants during critical periods of white matter development.

Attenuation of alpha2A-adrenergic receptor expression in neonatal rat brain by RNA interference or antisense oligonucleotide reduced anxiety in adulthood.

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Shishkina, G T; Kalinina, T S; Dygalo, N N

2004-01-01

Brain alpha2-adrenergic receptors (alpha2-ARs) have been implicated in the regulation of anxiety, which is associated with stress. Environmental treatments during neonatal development could modulate the level of brain alpha2-AR expression and alter anxiety in adults, suggesting possible involvement of these receptors in early-life programming of anxiety state. The present study was undertaken to determine whether the reduction of the expression of A subtype of these receptors most abundant in the neonatal brain affects anxiety-related behavior in adulthood. We attenuated the expression of alpha2A-ARs during neonatal life by two different sequence specific approaches, antisense technology and RNA interference. Treatment of rats with the antisense oligodeoxynucleotide or short interfering RNA (siRNA) against alpha2A-ARs on the days 2-4 of their life, produced a marked acute decrease in the levels of both alpha2A-AR mRNA and [3H]RX821002 binding sites in the brainstem into which drugs were injected. The decrease of alpha2A-AR expression in the neonatal brainstem influenced the development of this receptor system in the brain regions as evidenced by the increased number of [3H]RX821002 binding sites in the hypothalamus of adult animals with both neonatal alpha2A-AR knockdown treatments; also in the frontal cortex of antisense-treated, and in the hippocampus of siRNA-treated adult rats. These adult animals also demonstrated a decreased anxiety in the elevated plus-maze as evidenced by an increased number of the open arm entries, greater proportion of time spent in the open arms, and more than a two-fold increase in the number of exploratory head dips. The results provide the first evidence that the reduction in the brain expression of a gene encoding for alpha2A-AR during neonatal life led to the long-term neurochemical and behavioral alterations. The data suggests that alterations in the expression of the receptor-specific gene during critical periods of brain

Influence of age on the passage of paraquat through the blood-brain barrier in rats: a distribution and pathological examination

International Nuclear Information System (INIS)

Widdowson, P.S.; Farnworth, M.J.; Simpson, M.G.; Lock, E.A.

1996-01-01

Experiments were performed to determine the extent of paraquat entry into the brain of neonatal and elderly rats, as compared with adult rats, which may be dependent on the efficacy of the blood-brain barrier. A single, median lethal dose (20 mg/kg s.c.) of paraquat containing [14C]paraquat was administered to neonatal (10 day old), adult (3 month old) and elderly (18 month old) rats. In contrast to the adult and elderly rats where paraquat levels fell over the 24 h post-dosing period to negligible levels, paraquat concentrations in neonatal brains did not decrease with time between 0.5 and 24 h following dosing. The distribution of [14C]paraquat was measured in selective brain regions using quantitative autoradiography in all three age groups of rats, 30 min and 24 h following dosing. Autoradiography demonstrated that brain paraquat distributions were similar in the rat age groups. Most of the paraquat was confined to regions outside the blood-brain barrier and to brain regions that lack a complete blood-brain barrier e.g. dorsal hypothalamus, area postrema and the anterior olfactory bulb. Between 0.5 h and 24 h following dosing, paraquat concentrations in deeper brain structures, some distance away from the sites of entry, began to slowly increase in all the rat age groups. By 24 h following dosing, a majority of brain regions examined using quantitative autoradiography revealed significantly higher paraquat concentrations in neonatal brains as compared to brain regions of adult and elderly rats. Despite increased paraquat entry into neonatal brain, we could find no evidence for paraquat-induced neuronal cell damage following a detailed histopathological examination of perfused-fixed brains. In conclusion, impaired blood-brain barrier integrity in neonatal brain thus permitting more paraquat to enter than in adult brain, did not result in neuronal damage

A Novel Dynamic Neonatal Blood-Brain Barrier on a Chip.

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Sudhir P Deosarkar

Full Text Available Studies of neonatal neural pathologies and development of appropriate therapeutics are hampered by a lack of relevant in vitro models of neonatal blood-brain barrier (BBB. To establish such a model, we have developed a novel blood-brain barrier on a chip (B3C that comprises a tissue compartment and vascular channels placed side-by-side mimicking the three-dimensional morphology, size and flow characteristics of microvessels in vivo. Rat brain endothelial cells (RBEC isolated from neonatal rats were seeded in the vascular channels of B3C and maintained under shear flow conditions, while neonatal rat astrocytes were cultured under static conditions in the tissue compartment of the B3C. RBEC formed continuous endothelial lining with a central lumen along the length of the vascular channels of B3C and exhibited tight junction formation, as measured by the expression of zonula occludens-1 (ZO-1. ZO-1 expression significantly increased with shear flow in the vascular channels and with the presence of astrocyte conditioned medium (ACM or astrocytes cultured in the tissue compartment. Consistent with in vivo BBB, B3C allowed endfeet-like astrocyte-endothelial cell interactions through a porous interface that separates the tissue compartment containing cultured astrocytes from the cultured RBEC in the vascular channels. The permeability of fluorescent 40 kDa dextran from vascular channel to the tissue compartment significantly decreased when RBEC were cultured in the presence of astrocytes or ACM (from 41.0 ± 0.9 x 10-6 cm/s to 2.9 ± 1.0 x 10-6 cm/s or 1.1±0.4 x 10-6 cm/s, respectively. Measurement of electrical resistance in B3C further supports that the addition of ACM significantly improves the barrier function in neonatal RBEC. Moreover, B3C exhibits significantly improved barrier characteristics compared to the transwell model and B3C permeability was not significantly different from the in vivo BBB permeability in neonatal rats. In summary, we

Histopathological alterations in neonate after in utero irradiation of rats

International Nuclear Information System (INIS)

Abdel Gawad, I.I.

2000-01-01

Series of experiments were performed to study the histopathological changes induced in embryonic tissue during various stages of gestation in female rats after gamma irradiation. Pregnant rats were exposed to doses 0.5, 1,2 and 3 Gy on 9 th 12 th and 15 th days of gestation. Histopathological changes were detected in tissues of neonates, namely, liver ileum, kidney, brain, spleen, suprarenal, thymus, lungs and heart. These tissues showed variable degrees of radiation induced tissue changes. For quantifying these changes arbitrary scores were formulated to assess the type and severity of changes observed tissues of thirty six neonates randomly selected after radiation exposure of pregnant animals as scheduled

Mechanisms of Neuroprotection from Hypoxia-Ischemia (HI) Brain Injury by Up-regulation of Cytoglobin (CYGB) in a Neonatal Rat Model*

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Tian, Shu-Feng; Yang, Han-Hua; Xiao, Dan-Ping; Huang, Yue-Jun; He, Gu-Yu; Ma, Hai-Ran; Xia, Fang; Shi, Xue-Chuan

2013-01-01

This study was designed to investigate the expression profile of CYGB, its potential neuroprotective function, and underlying molecular mechanisms using a model of neonatal hypoxia-ischemia (HI) brain injury. Cygb mRNA and protein expression were evaluated within the first 36 h after the HI model was induced using RT-PCR and Western blotting. Cygb mRNA expression was increased at 18 h in a time-dependent manner, and its level of protein expression increased progressively in 24 h. To verify the neuroprotective effect of CYGB, a gene transfection technique was employed. Cygb cDNA and shRNA delivery adenovirus systems were established (Cygb-cDNA-ADV and Cygb-shRNA-ADV, respectively) and injected into the brains of 3-day-old rats 4 days before they were induced with HI treatment. Rats from different groups were euthanized 24 h post-HI, and brain samples were harvested. 2,3,5-Triphenyltetrazolium chloride, TUNEL, and Nissl staining indicated that an up-regulation of CYGB resulted in reduced acute brain injury. The superoxide dismutase level was found to be dependent on expression of CYGB. The Morris water maze test in 28-day-old rats demonstrated that CYGB expression was associated with improvement of long term cognitive impairment. Studies also demonstrated that CYGB can up-regulate mRNA and protein levels of VEGF and increase both the density and diameter of the microvessels but inhibits activation of caspase-2 and -3. Thus, this is the first in vivo study focusing on the neuroprotective role of CYGB. The reduction of neonatal HI injury by CYGB may be due in part to antioxidant and antiapoptotic mechanisms and by promoting angiogenesis. PMID:23585565

[Effects and consequence of recurrent seizures of neonatal rat on the hippocampal neurogenesis].

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Shi, Xiu-yu; Wang, Ji-wen; Sun, Ruo-peng

2006-04-01

Seizures occur more frequently in the neonatal period than at any other time in life. A controversy which has been debated for the recent years is whether recurrent neonatal seizures can lead to long-term adverse consequences or are simply a reflection of underlying brain dysfunction and are not intrinsically harmful. Despite numerous clinical observations showed that seizures may be detrimental to the developing brain, the pathological mechanism has not yet been completely understood. The goal of this study was to investigate what effect was induced by recurrent seizures in neonatal rats on dentate granule cell neurogenesis. Sixty-four neonatal Wistar rats were randomly divided into seizure group (n = 40) and control group (n = 24). The rats of seizure group were subjected to three times of pilocarpine injections intraperitonealy at postnatal day 1 (P1), 4 (P4) and 7 (P7). Neonatal rats of the control group were given saline injection (i.p.) at the same time points. The rat were sacrificed separately at the next four time points: immediately after the third seizure (P7), the fourth day after the seizure (P11), the fourteenth day (P21) and the forty fifth day (P52), corresponding control group rats were killed accordingly. The rats in both seizure and control groups were given bromodeoxyuridine (BrdU) injection 36 hours before sacrifice to indicate newly generated cells. Brain tissue sections were prepared and subjected to Nissl staining for neuronal loss, by BrdU labeling for cell proliferation and by BrdU + NF200 (neurofilament 200) double labeling for the identification of the newly formed cells. The numbers of BrdU-labeled cells were age-dependent in the control group, decreased with age, and their morphorlogy and distribution changed (P < 0.01). BrdU-labeled cells decreased significantly in the seizure group compared with the matched controls at P7 and P11 (P < 0.01), while at P21 there was no significant difficence between the two groups. On the contrary, Brd

The effect of iron and/or lactose on strontium metabolism in neonatal and weanling rats

International Nuclear Information System (INIS)

Gruden, N.; Mataushicj, S.

1988-01-01

Iron-fortified cow's milk increased strontium-85 retention in the femur and brain of neonatal rats by 16-44%, irrespective of the presence or absence of lactose. A similar effect was observed in the brain of weaning rats if milk was enriched with lactose and was not altered by simultaneous addition of iron. (author). 18 refs.; 1 tab

Minocycline Transiently Reduces Microglia/Macrophage Activation but Exacerbates Cognitive Deficits Following Repetitive Traumatic Brain Injury in the Neonatal Rat

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Hanlon, Lauren A.; Huh, Jimmy W.

2016-01-01

Elevated microglial/macrophage-associated biomarkers in the cerebrospinal fluid of infant victims of abusive head trauma (AHT) suggest that these cells play a role in the pathophysiology of the injury. In a model of AHT in 11-day-old rats, 3 impacts (24 hours apart) resulted in spatial learning and memory deficits and increased brain microglial/macrophage reactivity, traumatic axonal injury, neuronal degeneration, and cortical and white-matter atrophy. The antibiotic minocycline has been effective in decreasing injury-induced microglial/macrophage activation while simultaneously attenuating cellular and functional deficits in models of neonatal hypoxic ischemia, but the potential for this compound to rescue deficits after impact-based trauma to the immature brain remains unexplored. Acute minocycline administration in this model of AHT decreased microglial/macrophage reactivity in the corpus callosum of brain-injured animals at 3 days postinjury, but this effect was lost by 7 days postinjury. Additionally, minocycline treatment had no effect on traumatic axonal injury, neurodegeneration, tissue atrophy, or spatial learning deficits. Interestingly, minocycline-treated animals demonstrated exacerbated injury-induced spatial memory deficits. These results contrast with previous findings in other models of brain injury and suggest that minocycline is ineffective in reducing microglial/macrophage activation and ameliorating injury-induced deficits following repetitive neonatal traumatic brain injury. PMID:26825312

Effect of aging on phosphate metabolites of rat brain as revealed by the in vivo and in vitro 31P NMR measurements

International Nuclear Information System (INIS)

Liu, Hsiuchih; Chi, Chinwen; Liu, Tsungyun; Liu, Lianghui; Luh, Wenming; Hsieh, Changhuain; Wu, Wenguey

1991-01-01

Changes of phosphate metabolism in brains of neonate, weaning and adult rats were compared using both in vivo and in vitro nuclear magnetic resonance spectra. Ratios of phosphocreatine/nucleoside triphosphate (PCr/NTP) were the same in neonatal brain in both in vivo and in vitro studies, but not in weaning and adult brains. This discrepancy may have resulted from extended cerebral hypoxia due to slowed freezing of the brain by the increased skull thickness and brain mass in the weaning and adult rats. Variations of in vitro extraction condition for this age-related study may lead to systematic errors in the adult rats. Nevertheless, the phosphomonoester/nucleoside triphosphate (PME/NTP) ratios in extracts of brain from neonatal rats were higher than those obtained in vivo. In addition, the glycerophosphorylethanolamine plus glycerophosphorylcholine/nucleoside triphosphate (GPE+GPC/NTP) ratios, which were not measurable in vivo, showed age-dependent increase in extracts of rat brain. Some of the phosphomonoester and phosphodiester molecules in rat brain may be undetectable in in vivo NMR analysis because of their interaction with cellular components. The total in vitro GPE and GPC concentration in brain from neonatal rat was estimated to be 0.34 mmole/g wet tissue

Neurodevelopmental Reflex Testing in Neonatal Rat Pups.

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Nguyen, Antoinette T; Armstrong, Edward A; Yager, Jerome Y

2017-04-24

Neurodevelopmental reflex testing is commonly used in clinical practice to assess the maturation of the nervous system. Neurodevelopmental reflexes are also referred to as primitive reflexes. They are sensitive and consistent with later outcomes. Abnormal reflexes are described as an absence, persistence, reappearance, or latency of reflexes, which are predictive indices of infants that are at high risk for neurodevelopmental disorders. Animal models of neurodevelopmental disabilities, such as cerebral palsy, often display aberrant developmental reflexes, as would be observed in human infants. The techniques described assess a variety of neurodevelopmental reflexes in neonatal rats. Neurodevelopmental reflex testing offers the investigator a testing method that is not otherwise available in such young animals. The methodology presented here aims to assist investigators in examining developmental milestones in neonatal rats as a method of detecting early-onset brain injury and/or determining the effectiveness of therapeutic interventions. The methodology presented here aims to provide a general guideline for investigators.

Sodium Pyruvate Reduced Hypoxic-Ischemic Injury to Neonatal Rat Brain

OpenAIRE

Pan, Rui; Rong, Zhihui; She, Yun; Cao, Yuan; Chang, Li-Wen; Lee, Wei-Hua

2012-01-01

Background Neonatal hypoxia-ischemia (HI) remains a major cause of severe brain damage and is often associated with high mortality and lifelong disability. Immature brains are extremely sensitive to hypoxia-ischemia, shown as prolonged mitochondrial neuronal death. Sodium pyruvate (SP), a substrate of the tricarboxylic acid cycle and an extracellular antioxidant, has been considered as a potential treatment for hypoxic-ischemic encephalopathy (HIE), but its effects have not been evaluated in ...

Primary microglia isolation from mixed glial cell cultures of neonatal rat brain tissue.

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Tamashiro, Tami T; Dalgard, Clifton Lee; Byrnes, Kimberly R

2012-08-15

Microglia account for approximately 12% of the total cellular population in the mammalian brain. While neurons and astrocytes are considered the major cell types of the nervous system, microglia play a significant role in normal brain physiology by monitoring tissue for debris and pathogens and maintaining homeostasis in the parenchyma via phagocytic activity. Microglia are activated during a number of injury and disease conditions, including neurodegenerative disease, traumatic brain injury, and nervous system infection. Under these activating conditions, microglia increase their phagocytic activity, undergo morpohological and proliferative change, and actively secrete reactive oxygen and nitrogen species, pro-inflammatory chemokines and cytokines, often activating a paracrine or autocrine loop. As these microglial responses contribute to disease pathogenesis in neurological conditions, research focused on microglia is warranted. Due to the cellular heterogeneity of the brain, it is technically difficult to obtain sufficient microglial sample material with high purity during in vivo experiments. Current research on the neuroprotective and neurotoxic functions of microglia require a routine technical method to consistently generate pure and healthy microglia with sufficient yield for study. We present, in text and video, a protocol to isolate pure primary microglia from mixed glia cultures for a variety of downstream applications. Briefly, this technique utilizes dissociated brain tissue from neonatal rat pups to produce mixed glial cell cultures. After the mixed glial cultures reach confluency, primary microglia are mechanically isolated from the culture by a brief duration of shaking. The microglia are then plated at high purity for experimental study. The principle and protocol of this methodology have been described in the literature. Additionally, alternate methodologies to isolate primary microglia are well described. Homogenized brain tissue may be separated

Maternal hypoxia increases the activity of MMPs and decreases the expression of TIMPs in the brain of neonatal rats.

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Tong, Wenni; Chen, Wanqiu; Ostrowski, Robert P; Ma, Qingyi; Souvenir, Rhonda; Zhang, Lubo; Zhang, John H; Tang, Jiping

2010-02-15

A recent study has shown that increased activity of matrix metalloproteinases-2 and metalloproteinases-9 (MMP-2 and MMP-9) has detrimental effect on the brain after neonatal hypoxia. The present study determined the effect of maternal hypoxia on neuronal survivability and the activity of MMP-2 and MMP-9, as well as the expression of tissue inhibitors of metalloproteinase 1 and 2 (TIMP-1 and TIMP-2) in the brain of neonatal rats. Pregnant rats were exposed to 10.5% oxygen for 6 days from the gestation day 15 to day 21. Pups were sacrificed at day 0, 4, 7, 14, and 21 after birth. Body weight and brain weight of the pups were measured at each time point. The activity of MMP-2 and MMP-9 and the protein abundance of TIMP-1 and TIMP-2 were determined by zymography and Western blotting, respectively. The tissue distribution of MMPs was examined by immunofluorescence staining. The neuronal death was detected by Nissl staining. Maternal hypoxia caused significant decreases in body and brain size, increased activity of MMP-2 at day 0, and increased MMP-9 at day 0 and 4. The increased activity of the MMPs was accompanied by an overall tendency towards a reduced expression of TIMPs at all ages with the significance observed for TIMPs at day 0, 4, and 7. Immunofluorescence analysis showed an increased expression of MMP-2, MMP-9 in the hippocampus at day 0 and 4. Nissl staining revealed significant cell death in the hippocampus at day 0, 4, and 7. Functional tests showed worse neurobehavioral outcomes in the hypoxic animals.

Stromal Cell-Derived Factor-1α Plays a Crucial Role Based on Neuroprotective Role in Neonatal Brain Injury in Rats

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Miki Mori

2015-08-01

Full Text Available Owing to progress in perinatal medicine, the survival of preterm newborns has markedly increased. However, the incidence of cerebral palsy has risen in association with increased preterm birth. Cerebral palsy is largely caused by cerebral hypoxic ischemia (HI, for which there are no effective medical treatments. We evaluated the effects of stromal cell-derived factor-1α (SDF-1α on neonatal brain damage in rats. Left common carotid (LCC arteries of seven-day-old Wistar rat pups were ligated, and animals were exposed to hypoxic gas to cause cerebral HI. Behavioral tests revealed that the memory and spatial perception abilities were disturbed in HI animals, and that SDF-1α treatment improved these cognitive functions. Motor coordination was also impaired after HI but was unimproved by SDF-1α treatment. SDF-1α reduced intracranial inflammation and induced cerebral remyelination, as indicated by the immunohistochemistry results. These data suggest that SDF-1α specifically influences spatial perception abilities in neonatal HI encephalopathy.

Neonatal domoic acid decreases in vivo binding of [11C]yohimbine to α2 adrenoceptors in adult rat brain

DEFF Research Database (Denmark)

Thomsen, Majken; Lillethorup, Thea Pinholt; Jakobsen, Steen

day 8-14 with saline or one of two low sub-convulsive doses, 20µg/kg [DOM20] or 60µg/kg [DOM60] of DOM, an AMPA/kainate receptor agonist. The behaviour of the rats was observed in an open field test, a social interaction test and the forced swim test at day 50, 75 and 98, respectively. At ~120 days...... of age 3-4 rats per group were injected with [11C]yohimbine, an α2 adrenergic receptor antagonist and scanned in a micro positron emission tomography (PET) scanner. DOM60 spent more time in the periphery during the open field test and less time struggling in the forced swim test compared to the saline...... treated rats. microPET data revealed that DOM60 rats had a 40-47 % reduction in [11C]yohimbine binding in limbic and cortical brain regions relative to saline treated rats. We conclude that neonatal administration of DOM combined with the potential stress associated with behavioural testing results...

[Effects of electric stimulation at the cerebellar fastigial nucleus on astrocytes in the hippocampus of neonatal rats with hypoxic-ischemic brain damage].

Science.gov (United States)

Li, Xiao-Li; Jia, Tian-Ming; Luan, Bin; Liu, Tao; Yuan, Yan

2011-04-01

To study the effects of electric stimulation at the cerebellar fastigial nucleus on astrocytes in the hippocampus of neonatal rats with hypoxic-ischemic brain damage (HIBD) and the possible mechanism. One hundred and eighty 7-day-old neonatal Sprague-Dawley rats were randomly divided into three groups: sham-operation (control group) and HIBD with and without electric stimulation (n=60 each). The HIBD model of neonatal rats was prepared by the Rice-Vennucci method. Electric stimulation at the cerebellar fastigial nucleus was given 24 hrs after the operation in the electric stimulation group once daily and lasted for 30 minutes each time. The other two groups were not subjected to electric stimulation but captured to fix in corresponding periods. Rats were sacrificed 3, 7, 14 and 21 days after stimulations to observe the glial fibrillary acidic protein (GFAP) expression by immunohistochemisty and the ultrastructural changes of astrocytes in the hippocampus under an electron microscope. Immunohistochemical analysis showed the expression of GFAP in the HIBD groups with and without electric stimulation increased significantly compared with the control group on day 3, reached the peak on day 7, and the increased expression remained till to day 21. The GFAP expression in the electric stimulation group was significantly lower than that in the untreated HIBD group at all time points. Under the electron microscope, the astrocytes in the untreated HIBD group were swollen and the amount of organelles was reduced, while the swelling of astrocytes was alleviated and the organelles remained in integrity in the electric stimulation group. The electric stimulation at the cerebellar fastigial nucleus can inhibit the excessive proliferation of astrocytes and relieve the structural damage of astrocytes in neonatal rats following HIBD.

Characterization of cholinergic muscarinic receptor-stimulated phosphoinositide metabolism in brain from immature rats

International Nuclear Information System (INIS)

Balduini, W.; Murphy, S.D.; Costa, L.G.

1990-01-01

Hydrolysis of phosphoinositides elicited by stimulation of cholinergic muscarinic receptors has been studied in brain from neonatal (7-day-old) rats in order to determine: (1) whether the neonatal rat could provide a good model system to study this signal-transduction pathway; and (2) whether potential differences with adult nerve tissue would explain the differential, age-related effects of cholinergic agonists. Accumulation of [3H] inositol phosphates in [3H]inositol prelabeled slices from neonatal and adult rats was measured as an index of phosphoinositide metabolism. Full (acetylcholine, methacholine, carbachol) and partial (oxotremorine, bethanechol) agonists had qualitatively similar, albeit quantitatively different, effects in neonatal and adult rats. Atropine and pirenzepine effectively blocked the carbachol-induced response with inhibition constants of 1.2 and 20.7 nM, respectively. In all brain areas, response to all agonists was higher in neonatal than adult rats, and in hippocampus and cerebral cortex the response was higher than in cerebellum or brainstem. The relative intrinsic activity of partial agonists was higher in the latter two areas (0.6-0.7) than in the former two (0.3-0.4). Carbachol-stimulated phosphoinositide metabolism in brain areas correlated well with the binding of [3H]QNB (r2 = 0.627) and, particularly, with [3H]pirenzepine (r2 = 0.911). In cerebral cortex the effect of carbachol was additive to that of norepinephrine and glutamate. The presence of calcium (250-500 microM) was necessary for maximal response to carbachol to be elicited; the EC50 value for Ca2+ was 65.4 microM. Addition of EDTA completely abolished the response. Removal of sodium ions from the incubation medium reduced the response to carbachol by 50%

Atomoxetine, a selective norepinephrine reuptake inhibitor, improves short-term histological outcomes after hypoxic-ischemic brain injury in the neonatal male rat.

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Toshimitsu, Masatake; Kamei, Yoshimasa; Ichinose, Mari; Seyama, Takahiro; Imada, Shinya; Iriyama, Takayuki; Fujii, Tomoyuki

2018-03-30

Despite the recent progress of perinatal medicine, perinatal hypoxic-ischemic (HI) insult remains an important cause of brain injury in neonates, and is pathologically characterized by neuronal loss and the presence of microglia. Neurotransmitters, such as norepinephrine (NE) and glutamate, are involved in the pathogenesis of hypoxic-ischemic encephalopathy via the interaction between neurons and microglia. Although it is well known that the monoamine neurotransmitter NE acts as an anti-inflammatory agent in the brain under pathological conditions, its effects on perinatal HI insult remains elusive. Atomoxetine, a selective NE reuptake inhibitor, has been used clinically for the treatment of attention-deficit hyperactivity disorder in children. Here, we investigated whether the enhancement of endogenous NE by administration of atomoxetine could protect neonates against HI insult by using the neonatal male rat model. We also examined the involvement of microglia in this process. Unilateral HI brain injury was induced by the combination of left carotid artery dissection followed by ligation and hypoxia (8% O 2 , 2 h) in postnatal day 7 (P7) male rat pups. The pups were randomized into three groups: the atomoxetine treatment immediately after HI insult, the atomoxetine treatment at 3 h after HI insult, or the vehicle treatment group. The pups were euthanized on P8 and P14, and the brain regions including the cortex, striatum, hippocampus, and thalamus were evaluated by immunohistochemistry. HI insult resulted in severe brain damage in the ipsilateral hemisphere at P14. Atomoxetine treatment immediately after HI insult significantly increased NE levels in the ipsilateral hemisphere at 1 h after HI insult and reduced the neuronal damage via the increased phosphorylation of cAMP response element-binding protein (pCREB) in all brain regions examined. In addition, the number of microglia was maintained under atomoxetine treatment compared with that of the vehicle

No improvement of neuronal metabolism in the reperfusion phase with melatonin treatment after hypoxic-ischemic brain injury in the neonatal rat.

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Berger, Hester R; Morken, Tora Sund; Vettukattil, Riyas; Brubakk, Ann-Mari; Sonnewald, Ursula; Widerøe, Marius

2016-01-01

Mitochondrial impairment is a key feature underlying neonatal hypoxic-ischemic (HI) brain injury and melatonin is potentially neuroprotective through its effects on mitochondria. In this study, we have used (1) H and (13) C NMR spectroscopy after injection of [1-(13) C]glucose and [1,2-(13) C]acetate to examine neuronal and astrocytic metabolism in the early reperfusion phase after unilateral HI brain injury in 7-day-old rat pups, exploring the effects of HI on mitochondrial function and the potential protective effects of melatonin on brain metabolism. One hour after hypoxia-ischemia, astrocytic metabolism was recovered and glycolysis was normalized, whereas mitochondrial metabolism in neurons was clearly impaired. Pyruvate carboxylation was also lower in both hemispheres after HI. The transfer of glutamate from neurons to astrocytes was higher whereas the transfer of glutamine from astrocytes to neurons was lower 1 h after HI in the contralateral hemisphere. Neuronal metabolism was equally affected in pups treated with melatonin (10 mg/kg) immediately after HI as in vehicle treated pups indicating that the given dose of melatonin was not capable of protecting the neuronal mitochondria in this early phase after HI brain injury. However, any beneficial effects of melatonin might have been masked by modulatory effects of the solvent dimethyl sulfoxide on cerebral metabolism. Neuronal and astrocytic metabolism was examined by (13) C and (1) H NMR spectroscopy in the early reperfusion phase after unilateral hypoxic-ischemic brain injury and melatonin treatment in neonatal rats. One hour after hypoxia-ischemia astrocytic mitochondrial metabolism had recovered and glycolysis was normalized, whereas mitochondrial metabolism in neurons was impaired. Melatonin treatment did not show a protective effect on neuronal metabolism. © 2015 International Society for Neurochemistry.

Intrapartum FHR monitoring and neonatal CT brain scan

International Nuclear Information System (INIS)

Takahashi, Yoshiki; Ukita, Masahiko; Nakada, Eizo

1982-01-01

The effect of fetal distress on the neonatal brain was investigated by neonatal CT brain scan, FHR monitoring and mode of delivery. This study involved 11 cases of full term vertex delivery in which FHR was recorded by fetal direct ECG during the second stage labor. All infants weighed 2,500 g or more. FHR monitoring was evaluated by Hon's classification. Neonatal brain edema was evaluated by cranial CT histgraphic analysis (Nakada's method). 1) Subdural hemorrhage was noted in 6 of 7 infants delivered by vacuum extraction or fundal pressure (Kristeller's method). 2) Intracranial hemorrhage was demonstrated in all of 3 infants with 5-min. Apgar score 7 or less. 3) Two cases with prolonged bradycardia and no variability had intraventricular or intracerebral hemorrhage which resulted in severe central nervous system damage. 4) The degree of neonatal brain edema correlated with 5-min. Apgar score. 5) One case with prolonged bradycardia and no variability resulted in severe neonatal brain edema. Four cases with variable deceleration and increased variability resulted in mild neonatal brain edema. Two cases with late deceleration and decreased variability resulted in no neonatal brain edema. (author)

Diffusion Weighted Imaging of the Neonatal Brain

NARCIS (Netherlands)

J. Dudink (Jeroen)

2010-01-01

textabstractAlthough in the last decades advances in fetal and neonatal medicine have reduced mortality in neonatal intensive care units in the Western world, the morbidity due to brain injury remains high. Patterns of neonatal brain injury can be roughly divided in (1) term and (2) preterm

Early evolution and recovery from excitotoxic injury in the neonatal rat brain

NARCIS (Netherlands)

Lookeren Campagne, van M.; Verheul, H.B.; Nicolaij, K.; Balázs, R.E.

1994-01-01

We explored the therapeutic potentials of two N-methyl-D-aspartate (NMDA) receptor antagonists in vivo using different techniques. NMDA injected into the striatum of neonatal rats (20 nmol/0.5 microliters) induced a rapid increase in the diffusion-weighted (DW) image intensity, spreading over a

Differential effect of maternal diet supplementation with α-Linolenic adcid or n-3 long-chain polyunsaturated fatty acids on glial cell phosphatidylethanolamine and phosphatidylserine fatty acid profile in neonate rat brains

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Cruz-Hernandez Cristina

2010-01-01

Full Text Available Abstract Background Dietary long-chain polyunsaturated fatty acids (LC-PUFA are of crucial importance for the development of neural tissues. The aim of this study was to evaluate the impact of a dietary supplementation in n-3 fatty acids in female rats during gestation and lactation on fatty acid pattern in brain glial cells phosphatidylethanolamine (PE and phosphatidylserine (PS in the neonates. Methods Sprague-Dawley rats were fed during the whole gestation and lactation period with a diet containing either docosahexaenoic acid (DHA, 0.55% and eicosapentaenoic acid (EPA, 0.75% of total fatty acids or α-linolenic acid (ALA, 2.90%. At two weeks of age, gastric content and brain glial cell PE and PS of rat neonates were analyzed for their fatty acid and dimethylacetal (DMA profile. Data were analyzed by bivariate and multivariate statistics. Results In the neonates from the group fed with n-3 LC-PUFA, the DHA level in gastric content (+65%, P Conclusion The present study confirms that early supplementation of maternal diet with n-3 fatty acids supplied as LC-PUFA is more efficient in increasing n-3 in brain glial cell PE and PS in the neonate than ALA. Negative correlation between n-6 DPA, a conventional marker of DHA deficiency, and DMA in PE suggests n-6 DPA that potentially be considered as a marker of tissue ethanolamine plasmalogen status. The combination of multivariate and bivariate statistics allowed to underline that the accretion pattern of n-3 LC-PUFA in PE and PS differ.

Perinatal supplementation with omega-3 polyunsaturated fatty acids improves sevoflurane-induced neurodegeneration and memory impairment in neonatal rats.

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Xi Lei

Full Text Available OBJECTIVES: To investigate if perinatal Omega-3 polyunsaturated fatty acids (n-3 PUFAs supplementation can improve sevoflurane-induced neurotoxicity and cognitive impairment in neonatal rats. METHODS: Female Sprague-Dawley rats (n = 3 each group were treated with or without an n-3 PUFAs (fish oil enriched diet from the second day of pregnancy to 14 days after parturition. The offspring rats (P7 were treated with six hours sevoflurane administration (one group without sevoflurane/prenatal n-3 PUFAs supplement as control. The 5-bromodeoxyuridine (Brdu was injected intraperitoneally during and after sevoflurane anesthesia to assess dentate gyrus (DG progenitor proliferation. Brain tissues were harvested and subjected to Western blot and immunohistochemistry respectively. Morris water maze spatial reference memory, fear conditioning, and Morris water maze memory consolidation were tested at P35, P63 and P70 (n = 9, respectively. RESULTS: Six hours 3% sevoflurane administration increased the cleaved caspase-3 in the thalamus, parietal cortex but not hippocampus of neonatal rat brain. Sevoflurane anesthesia also decreased the neuronal precursor proliferation of DG in rat hippocampus. However, perinatal n-3 PUFAs supplement could decrease the cleaved caspase-3 in the cerebral cortex of neonatal rats, and mitigate the decrease in neuronal proliferation in their hippocampus. In neurobehavioral studies, compared with control and n-3 PUFAs supplement groups, we did not find significant spatial cognitive deficit and early long-term memory impairment in sevoflurane anesthetized neonatal rats at their adulthood. However, sevoflurane could impair the immediate fear response and working memory and short-term memory. And n-3 PUFAs could improve neurocognitive function in later life after neonatal sevoflurane exposure. CONCLUSION: Our study demonstrated that neonatal exposure to prolonged sevoflurane could impair the immediate fear response, working

Does Neonatal Brain Ischemia Induce Schizophrenia-Like Behavior in Young Adult Rats?

Czech Academy of Sciences Publication Activity Database

Tejkalová, H.; Kaiser, M.; Klaschka, Jan; Šťastný, František

2007-01-01

Roč. 56, č. 6 (2007), s. 815-823 ISSN 0862-8408 R&D Projects: GA MZd(CZ) NR8797 Institutional research plan: CEZ:AV0Z10300504; CEZ:AV0Z50110509 Keywords : neonatal ischemia * schizophrenia * rat * prepulse inhibition Subject RIV: FL - Psychiatry, Sexuology Impact factor: 1.505, year: 2007

Developmental hyperoxia alters CNS mechanisms underlying hypoxic ventilatory depression in neonatal rats.

Science.gov (United States)

Hill, Corey B; Grandgeorge, Samuel H; Bavis, Ryan W

2013-12-01

Newborn mammals exhibit a biphasic hypoxic ventilatory response (HVR), but the relative contributions of carotid body-initiated CNS mechanisms versus central hypoxia on ventilatory depression during the late phase of the HVR are not well understood. Neonatal rats (P4-5 or P13-15) were treated with a nonselective P2 purinergic receptor antagonist (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid, or PPADS; 125mgkg(-1), i.p.) to pharmacologically denervate the peripheral chemoreceptors. At P4-5, rats reared in normoxia showed a progressive decline in ventilation during a 10-min exposure to 12% O2 (21-28% decrease from baseline). No hypoxic ventilatory depression was observed in the older group of neonatal rats (i.e., P13-15), suggesting that the contribution of central hypoxia to hypoxic ventilatory depression diminishes with age. In contrast, rats reared in moderate hyperoxia (60% O2) from birth exhibited no hypoxic ventilatory depression at either age studied. Systemic PPADS had no effect on the ventilatory response to 7% CO2, suggesting that the drug did not cross the blood-brain barrier. These findings indicate that (1) CNS hypoxia depresses ventilation in young, neonatal rats independent of carotid body activation and (2) hyperoxia alters the development of CNS pathways that modulate the late phase of the hypoxic ventilatory response. Copyright © 2013 Elsevier B.V. All rights reserved.

Feeding Vitamin C during Neonatal and Juvenile Growth Improves Learning and Memory of Rats.

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Hosseini, Mahmoud; Beheshti, Farimah; Sohrabi, Farzaneh; Vafaee, Farzaneh; Shafei, Mohammad Naser; Reza Sadeghnia, Hamid

2018-09-03

We investigated the effects of feeding vitamin C (Vit C) during neonatal and juvenile growth on learning and memory of rats. Rats after delivery were randomly divided into four groups and treated. Group 1, control group, received normal drinking water. Groups 2-4 received Vit C 10, 100, and 500 mg/kg, respectively, from the first day. After 8 weeks, 10 male offspring of each group were randomly selected and tested in the Morris water maze (MWM) and passive avoidance (PA) tests. Finally, the brains were removed for biochemical measurement. In MWM, 10-500 mg/kg Vit C reduced the latency and traveled distance and increased time spent in the target quadrant. In PA, 10 and 100 mg/kg of Vit C increased the latency; 10-500 mg/kg of Vit C decreased the malondialdehyde (MDA) in the brain tissues and increased thiol and catalase (CAT) activity compared to the control group. We showed that feeding rats Vit C during neonatal and juvenile growth has positive effects on learning and memory.

Structural connectivity asymmetry in the neonatal brain.

Science.gov (United States)

Ratnarajah, Nagulan; Rifkin-Graboi, Anne; Fortier, Marielle V; Chong, Yap Seng; Kwek, Kenneth; Saw, Seang-Mei; Godfrey, Keith M; Gluckman, Peter D; Meaney, Michael J; Qiu, Anqi

2013-07-15

Asymmetry of the neonatal brain is not yet understood at the level of structural connectivity. We utilized DTI deterministic tractography and structural network analysis based on graph theory to determine the pattern of structural connectivity asymmetry in 124 normal neonates. We tracted white matter axonal pathways characterizing interregional connections among brain regions and inferred asymmetry in left and right anatomical network properties. Our findings revealed that in neonates, small-world characteristics were exhibited, but did not differ between the two hemispheres, suggesting that neighboring brain regions connect tightly with each other, and that one region is only a few paths away from any other region within each hemisphere. Moreover, the neonatal brain showed greater structural efficiency in the left hemisphere than that in the right. In neonates, brain regions involved in motor, language, and memory functions play crucial roles in efficient communication in the left hemisphere, while brain regions involved in emotional processes play crucial roles in efficient communication in the right hemisphere. These findings suggest that even at birth, the topology of each cerebral hemisphere is organized in an efficient and compact manner that maps onto asymmetric functional specializations seen in adults, implying lateralized brain functions in infancy. Copyright © 2013 Elsevier Inc. All rights reserved.

The perinatal effects of maternal caffeine intake on fetal and neonatal brain levels of testosterone, estradiol, and dihydrotestosterone in rats.

Science.gov (United States)

Karaismailoglu, S; Tuncer, M; Bayrak, S; Erdogan, G; Ergun, E L; Erdem, A

2017-08-01

Testosterone, estradiol, and dihydrotestosterone are the main sex steroid hormones responsible for the organization and sexual differentiation of brain structures during early development. The hypothalamo-pituitary-adrenocortical axis, adrenal cells, and gonads play a key role in the production of sex steroids and express adenosine receptors. Caffeine is a non-selective adenosine antagonist; therefore, it can modulate metabolic pathways in these tissues. Besides, the proportion of pregnant women that consume caffeine is ∼60%. That is why the relationship between maternal caffeine consumption and fetal development is important. Therefore, we aimed to investigate this modulatory effect of maternal caffeine consumption on sex steroids in the fetal and neonatal brain tissues. Pregnant rats were treated with a low (0.3 g/L) or high (0.8 g/L) dose of caffeine in their drinking water during pregnancy and lactation. The testosterone, estradiol, and dihydrotestosterone levels in the frontal cortex and hypothalamus were measured using radioimmunoassay at embryonic day 19 (E19), birth (PN0), and postnatal day 4 (PN4). The administration of low-dose caffeine increased the body weight in PN4 male and female rats and anogenital index in PN4 males. The administration of high-dose caffeine decreased the adrenal weight in E19 male rats and increased testosterone levels in the frontal cortex of E19 female rats and the hypothalamus of PN0 male rats. Maternal caffeine intake during pregnancy affects sex steroid levels in the frontal cortex and hypothalamus of the offspring. This concentration changes of the sex steroids in the brain may influence behavioral and neuroendocrine functions at some point in adult life.

Neonatal infection produces significant changes in immune function with no associated learning deficits in juvenile rats.

Science.gov (United States)

Osborne, Brittany F; Caulfield, Jasmine I; Solomotis, Samantha A; Schwarz, Jaclyn M

2017-10-01

The current experiments examined the impact of early-life immune activation and a subsequent mild immune challenge with lipopolysaccharide (LPS; 25µg/kg) on hippocampal-dependent learning, proinflammatory cytokine expression in the brain, and peripheral immune function in juvenile male and female rats at P24, an age when hippocampal-dependent learning and memory first emerges. Our results indicate that neonatal infection did not produce learning deficits in the hippocampal-dependent context pre-exposure facilitation effect paradigm in juvenile males and females, contrary to what has been observed in adults. Neonatal infection produced an increase in baseline IL-1β expression in the hippocampus (HP) and medial prefrontal cortex (mPFC) of juvenile rats. Furthermore, neonatally infected rats showed exaggerated IL-1β expression in the HP following LPS treatment as juveniles; and juvenile females, but not males, showed exaggerated IL-1β expression in the mPFC following LPS treatment. Neonatal infection attenuated the production of IL-6 expression following LPS treatment in both the brain and the spleen, and neonatal infection decreased the numbers of circulating white blood cells in juvenile males and females, an effect that was further exacerbated by subsequent LPS treatment. Together, our data indicate that the consequences of neonatal infection are detectable even early in juvenile development, though we found no concomitant hippocampal-dependent learning deficits at this young age. These findings underscore the need to consider age and associated on-going neurodevelopmental processes as important factors contributing to the emergence of cognitive and behavioral disorders linked to early-life immune activation. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1221-1236, 2017. © 2017 Wiley Periodicals, Inc.

Glucose metabolism and astrocyte-neuron interactions in the neonatal brain.

Science.gov (United States)

Brekke, Eva; Morken, Tora Sund; Sonnewald, Ursula

2015-03-01

Glucose is essentially the sole fuel for the adult brain and the mapping of its metabolism has been extensive in the adult but not in the neonatal brain, which is believed to rely mainly on ketone bodies for energy supply. However, glucose is absolutely indispensable for normal development and recent studies have shed light on glycolysis, the pentose phosphate pathway and metabolic interactions between astrocytes and neurons in the 7-day-old rat brain. Appropriately (13)C labeled glucose was used to distinguish between glycolysis and the pentose phosphate pathway during development. Experiments using (13)C labeled acetate provided insight into the GABA-glutamate-glutamine cycle between astrocytes and neurons. It could be shown that in the neonatal brain the part of this cycle that transfers glutamine from astrocytes to neurons is operating efficiently while, in contrast, little glutamate is shuttled from neurons to astrocytes. This lack of glutamate for glutamine synthesis is compensated for by anaplerosis via increased pyruvate carboxylation relative to that in the adult brain. Furthermore, compared to adults, relatively more glucose is prioritized to the pentose phosphate pathway than glycolysis and pyruvate dehydrogenase activity. The reported developmental differences in glucose metabolism and neurotransmitter synthesis may determine the ability of the brain at various ages to resist excitotoxic insults such as hypoxia-ischemia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ketamine analgesia for inflammatory pain in neonatal rats: a factorial randomized trial examining long-term effects

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Bhutta Adnan T

2008-08-01

Full Text Available Abstract Background Neonatal rats exposed to repetitive inflammatory pain have altered behaviors in young adulthood, partly ameliorated by Ketamine analgesia. We examined the relationships between protein expression, neuronal survival and plasticity in the neonatal rat brain, and correlated these changes with adult cognitive behavior. Methods Using Western immunoblot techniques, homogenates of cortical tissue were analyzed from neonatal rats 18–20 hours following repeated exposure to 4% formalin injections (F, N = 9, Ketamine (K, 2.5 mg/kg × 2, N = 9, Ketamine prior to formalin (KF, N = 9, or undisturbed controls (C, N = 9. Brain tissues from another cohort of rat pups (F = 11, K = 12, KF = 10, C = 15 were used for cellular staining with Fos immunohistochemistry or FluoroJade-B (FJB, followed by cell counting in eleven cortical and three hippocampal areas. Long-term cognitive testing using a delayed non-match to sample (DNMS paradigm in the 8-arm radial maze was performed in adult rats receiving the same treatments (F = 20, K = 24, KF = 21, C = 27 in the neonatal period. Results Greater cell death occurred in F vs. C, K, KF in parietal and retrosplenial areas, vs. K, KF in piriform, temporal, and occipital areas, vs. C, K in frontal and hindlimb areas. In retrosplenial cortex, less Fos expression occurred in F vs. C, KF. Cell death correlated inversely with Fos expression in piriform, retrosplenial, and occipital areas, but only in F. Cortical expression of glial fibrillary acidic protein (GFAP was elevated in F, K and KF vs. C. No significant differences occurred in Caspase-3, Bax, and Bcl-2 expression between groups, but cellular changes in cortical areas were significantly correlated with protein expression patterns. Cluster analysis of the frequencies and durations of behaviors grouped them as exploratory, learning, preparatory, consumptive, and foraging behaviors. Neonatal inflammatory pain exposure reduced exploratory behaviors in adult

Patterns of neonatal hypoxic-ischaemic brain injury

International Nuclear Information System (INIS)

Vries, Linda S. de; Groenendaal, Floris

2010-01-01

Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome. (orig.)

Patterns of neonatal hypoxic-ischaemic brain injury

Energy Technology Data Exchange (ETDEWEB)

Vries, Linda S. de [University Medical Centre, Department of Neonatology, Wilhelmina Children' s Hospital, Utrecht (Netherlands); Wilhelmina Children' s Hospital, University Medical Centre, Department of Neonatology, KE 04.123.1, P.O. Box 85090, Utrecht (Netherlands); Groenendaal, Floris [University Medical Centre, Department of Neonatology, Wilhelmina Children' s Hospital, Utrecht (Netherlands)

2010-06-15

Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome. (orig.)

Prophylactic administration of melatonin to the mother throughout pregnancy can protect against oxidative cerebral damage in neonatal rats.

Science.gov (United States)

Watanabe, Kazushi; Hamada, Fumiaki; Wakatsuki, Akihiko; Nagai, Ryuhei; Shinohara, Koichi; Hayashi, Yoshihiro; Imamura, Rina; Fukaya, Takao

2012-08-01

The purpose of this study was to investigate whether prophylactic administration of melatonin to the mother throughout pregnancy could protect against ischemia/reperfusion (I/R)-induced oxidative brain damage in neonatal rats. The utero-ovarian arteries were occluded bilaterally for 30 min in female Wistar rats on day 16 of pregnancy to induce fetal ischemia. Reperfusion was achieved by releasing the occlusion and restoring circulation. A sham operation was performed in control rats. Melatonin solution or vehicle alone was administrated orally throughout pregnancy. We collected brain mitochondria from neonatal rats, evaluated mitochondrial structure by electron microscopy, and measured the respiratory control index (RCI) as an indicator of mitochondrial respiratory activity as well as the concentration of thiobarbituric acid-reactive substances (TBARS), a marker of oxidative stress. Histological analysis was performed at the Cornu Ammonis 1 (CA1) and Cornu Ammonis 3 (CA3) regions of the hippocampus. I/R significantly reduced the RCI and significantly elevated the concentration of TBARS. Melatonin treatment reversed these effects, resulting in values similar to that in untreated, sham-ischemic animals. Electron microscopic evaluation showed that the number of intact mitochondria decreased in the I/R group, while melatonin treatment preserved them. Histological analysis revealed a decrease in the ratio of normal to whole pyramidal cell number in the CA1 and CA3 regions in the I/R group. While melatonin administration protected against degeneration. These results indicate that prophylactic administration of melatonin to the mother throughout pregnancy may prevent I/R-induced oxidative brain damage in neonatal rats.

Interactive toxicity of chlorpyrifos and parathion in neonatal rats: Role of esterases in exposure sequence-dependent toxicity

International Nuclear Information System (INIS)

Kacham, R.; Karanth, S.; Baireddy, P.; Liu, J.; Pope, C.

2006-01-01

We previously reported that sequence of exposure to chlorpyrifos and parathion in adult rats can markedly influence toxic outcome. In the present study, we evaluated the interactive toxicity of chlorpyrifos (8 mg/kg, po) and parathion (0.5 mg/kg, po) in neonatal (7 days old) rats. Rats were exposed to the insecticides either concurrently or sequentially (separated by 4 h) and sacrificed at 4, 8, and 24 h after the first exposure for biochemical measurements (cholinesterase activity in brain, plasma, and diaphragm and carboxylesterase activity in plasma and liver). The concurrently-exposed group showed more cumulative lethality (15/24) than either of the sequential dosing groups. With sequential dosing, rats treated initially with chlorpyrifos prior to parathion (C/P) exhibited higher lethality (7/23) compared to those treated with parathion before chlorpyrifos (P/C; 1/24). At 8 h after initial dosing, brain cholinesterase inhibition was significantly greater in the C/P group (59%) compared to the P/C group (28%). Diaphragm and plasma cholinesterase activity also followed a relatively similar pattern of inhibition. Carboxylesterase inhibition in plasma and liver was relatively similar among the treatment groups across time-points. Similar sequence-dependent differences in brain cholinesterase inhibition were also noted with lower binary exposures to chlorpyrifos (2 mg/kg) and parathion (0.35 mg/kg). In vitro and ex vivo studies compared relative oxon detoxification of carboxylesterases (calcium-insensitive) and A-esterases (calcium-sensitive) in liver homogenates from untreated and insecticide pretreated rats. Using tissues from untreated rats, carboxylesterases detoxified both chlorpyrifos oxon and paraoxon, while A-esterases only detoxified chlorpyrifos oxon. With parathion pretreatment, A-esterases still detoxified chlorpyrifos oxon while liver from chlorpyrifos pretreated rats had little apparent effect on paraoxon. We conclude that while neonatal rats are less

Structural Connectivity Asymmetry in the Neonatal Brain

OpenAIRE

Ratnarajah, Nagulan; Rifkin-Graboi, Anne; Fortier, Marielle V.; Chong, Yap Seng; Kwek, Kenneth; Saw, Seang-Mei; Godfrey, Keith M; Gluckman, Peter D.; Meaney, Michael J.; Qiu, Anqi

2013-01-01

Asymmetry of the neonatal brain is not yet understood at the level of structural connectivity. We utilized DTI deterministic tractography and structural network analysis based on graph theory to determine the pattern of structural connectivity asymmetry in 124 normal neonates. We tracted white matter axonal pathways characterizing interregional connections among brain regions and inferred asymmetry in left and right anatomical network properties. Our findings revealed that in neonates, small-...

Multidimensional MRI-CT atlas of the naked mole-rat brain

Directory of Open Access Journals (Sweden)

Fumiko eSeki

2013-12-01

Full Text Available Naked mole-rats have a variety of distinctive features such as the organisation of a hierarchical society (known as eusociality, extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI, which generates high contrast images of fibre structures, can characterise unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography (CT were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualisation of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

Neonatal domoic acid increases receptor density of α2 adrenoceptors and GABAA α5 receptors in limbic brain regions of adult rats

DEFF Research Database (Denmark)

Thomsen, Majken; Lillethorup, Thea Pinholt; Wegener, Gregers

Background: The presymptomatic events involved in neurological disorders such as epilepsy remain elusive but represent an opportunity to understand disease development and stop the pathogenic processes leading to chronic epilepsy. Previous studies using Western blot and immunohistochemistry have...... found increased levels of α2 adrenoceptors in the hippocampal membrane of adult rats treated neonatally with low-dose domoic acid (DOM) along with decreased levels of both isoforms of glutamic acid decarboxylase (GAD), a catalyst of the decarboxylation of glutamate to GABA, indicating a reduction...... in GABAergic interneurons. Objectives: The aim of the present study was to investigate the expression of GABAA α5 and α2 adrenoceptors in limbic brain regions in a DOM rat model of epilepsy using autoradiography. Methods: Male Sprague-Dawley rats (N=3) were injected (s.c.) daily from postnatal day 8...

Neonatal manipulation of oxytocin prevents lipopolysaccharide-induced decrease in gene expression of growth factors in two developmental stages of the female rat.

Science.gov (United States)

Bakos, Jan; Lestanova, Zuzana; Strbak, Vladimir; Havranek, Tomas; Bacova, Zuzana

2014-10-01

Oxytocin production and secretion is important for early development of the brain. Long-term consequences of manipulation of oxytocin system might include changes in markers of brain plasticity - cytoskeletal proteins and neurotrophins. The aim of the present study was (1) to determine whether neonatal oxytocin administration affects gene expression of nestin, microtubule-associated protein-2 (MAP-2), brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the brain of two developmental stages of rat and (2) to evaluate whether neonatal oxytocin administration protects against lipopolysaccharide (LPS) induced inflammation. Neonatal oxytocin did not prevent a decrease of body weight in the LPS treated animals. Oxytocin significantly increased gene expression of BDNF in the right hippocampus in 21-day and 2-month old rats of both sexes. Gene expression of NGF and MAP-2 significantly increased in males treated with oxytocin. Both, growth factors and intermediate filament-nestin mRNA levels, were reduced in females exposed to LPS. Oxytocin treatment prevented a decrease in the gene expression of only growth factors. In conclusion, neonatal manipulation of oxytocin has developmental and sex-dependent effect on markers of brain plasticity. These results also indicate, that oxytocin may be protective against inflammation particularly in females. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sex-related differences in effects of progesterone following neonatal hypoxic brain injury.

Science.gov (United States)

Peterson, Bethany L; Won, Soonmi; Geddes, Rastafa I; Sayeed, Iqbal; Stein, Donald G

2015-06-01

There is no satisfactory therapeutic intervention for neonatal hypoxic-ischemic (HI) encephalopathy. Progesterone is known to be effective in treating traumatic brain injury in adult animals but its effects in neonatal brains have not been reported. Brain injuries were induced by a unilateral common carotid artery ligation plus hypoxia exposure. Progesterone was administered immediately after hypoxia and daily for 5 days at 8 mg/kg, followed by a tapered dose for two days. At six weeks post-injury, lesion size and inflammatory factors were evaluated. Progesterone-treated, HI-injured male animals, but not females, showed significant long-term tissue protection compared to vehicle, suggesting an important sex difference in neuroprotection. Progesterone-treated, HI-injured male rats had fewer activated microglia in the cortex and hippocampus compared to controls. The rats were tested for neurological reflexes, motor asymmetry, and cognitive performance at multiple time points. The injured animals exhibited few detectable motor deficits, suggesting a high level of age- and injury-related neuroplasticity. There were substantial sex differences on several behavioral tests, indicating that immature males and females should be analyzed separately. Progesterone-treated animals showed modest beneficial effects in both sexes compared to vehicle-treated injured animals. Sham animals given progesterone did not behave differently from vehicle-treated sham animals on any measures. Copyright © 2015 Elsevier B.V. All rights reserved.

Two-hit model of schizophrenia induced by neonatal immune activation and peripubertal stress in rats: Study of sex differences and brain oxidative alterations.

Science.gov (United States)

Monte, Aline Santos; Mello, Bruna Stefânia Ferreira; Borella, Vládia Célia Moreira; da Silva Araujo, Tatiane; da Silva, Francisco Eliclécio Rodrigues; Sousa, Francisca Cléa F de; de Oliveira, Antônio Carlos Pinheiro; Gama, Clarissa Severino; Seeman, Mary V; Vasconcelos, Silvânia Maria Mendes; Lucena, David Freitas De; Macêdo, Danielle

2017-07-28

Schizophrenia is considered to be a developmental disorder with distinctive sex differences. Aiming to simulate the vulnerability of the third trimester of human pregnancy to the developmental course of schizophrenia, an animal model was developed, using neonatal poly(I:C) as a first-hit, and peripubertal stress as a second-hit, i.e. a two-hit model. Since, to date, there have been no references to sex differences in the two-hit model, our study sought to determine sex influences on the development of behavior and brain oxidative change in adult rats submitted to neonatal exposure to poly(I:C) on postnatal days 5-7 as well as peripubertal unpredictable stress (PUS). Our results showed that adult two-hit rats present sex-specific behavioral alterations, with females showing more pronounced deficits in prepulse inhibition of the startle reflex and hyperlocomotion, while males showing more deficits in social interaction. Male and female animals exhibited similar working memory deficits. The levels of the endogenous antioxidant, reduced glutathione, were decreased in the prefrontal cortex (PFC) of both male and female animals exposed to both poly(I:C) and poly(I:C)+PUS. Only females presented decrements in GSH levels in the striatum. Nitrite levels were increased in the PFC of male and in the striatum of female poly(I:C)+PUS rats. Increased lipid peroxidation was observed in the PFC of females and in the striatum of males and females exposed to poly(I:C) and poly(I:C)+PUS. Thus, the present study presents evidence for sex differences in behavior and oxidative brain change induced by a two-hit model of schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

T-cell proliferative responses following sepsis in neonatal rats.

Science.gov (United States)

Dallal, Ousama; Ravindranath, Thyyar M; Choudhry, Mashkoor A; Kohn, Annamarie; Muraskas, Jonathan K; Namak, Shahla Y; Alattar, Mohammad H; Sayeed, Mohammed M

2003-01-01

Both experimental and clinical evidence suggest a suppression of T-cell function in burn and sepsis. The objective of the present study was to evaluate splenocyte and purified T-cell proliferative response and IL-2 production in septic neonatal rats. We also examined if alterations in T-cell proliferation and IL-2 production in neonatal sepsis is due to elevation in PGE2. PGE2 is known to play a significant role in T-cell suppression during sepsis in adults. Sepsis was induced in 15-day-old neonatal Sprague-Dawley rats by implanting 0.1 cm3 of fecal pellet impregnated with Escherichia coli (50 CFU) and Bacteroides fragilis (10(3) CFU). Animals receiving fecal pellets without the bacteria were designated as sterile. A group of septic and sterile rats were treated with PGE2 synthesis inhibitors, NS398 and resveratrol. These treatments of animals allowed us to evaluate the role of PGE2 in T-cell suppression during neonatal sepsis. Splenocytes as well as purified T cells were prepared and then proliferative response and IL-2 productive capacities were measured. A significant suppression of splenocyte proliferation and IL-2 production was noticed in both sterile and septic animals compared to the T cells from unoperated control rats. In contrast, the proliferation and IL-2 production by nylon wool purified T cells in sterile rats was not significantly different from control rats, whereas, a significant suppression in Con A-mediated T-cell proliferation and IL-2 production noticed in septic rat T cells compared to the sterile and control rat T cells. Such decrease in T-cell proliferation and IL-2 production was accompanied with 20-25% deaths in neonates implanted with septic pellets. No mortality was noted in sterile-implanted neonates. Treatment of animals with COX-1 inhibitor had no effect on T-cell proliferation response in both septic and sterile groups, whereas COX-2 inhibitor abrogated the decrease in T-cell proliferative response in the septic group. The treatment

Influence of neonatal vitamin A or vitamin D treatment on the concentration of biogenic amines and their metabolites in the adult rat brain.

Science.gov (United States)

Tekes, K; Gyenge, M; Folyovich, A; Csaba, G

2009-04-01

Newborn male rats were treated with a single dose of 3 mg vitamin A (retinol) or 0.05 mg vita-min D (cholecalciferol), and three months later five brain regions (frontopolar cortex, hypothalamus, hippocampus, striatum, and brainstem) were studied for tissue levels of dopamine (DA), serotonin (5HT), and metabolites such as homovanillic acid (HVA), as well as 5-hydroxyindole-3-acetic acid (5HIAA). Vitamin A treatment as hormonal imprinting significantly decreased 5HIAA levels in each brain region. Vitamin D imprinting significantly elevated DA only in the brainstem and HVA levels in striatum and hypothalamus. Present and earlier brain-imprinting results (with brain-produced substances), show that the profound and life-long effect of neonatal hormonal imprinting on neurotransmitter production of the adult brain seems to be well established. As prophylactic treatment with these vitamins is frequent in the perinatal period, the imprinting effect of vitamin A and vitamin D must be taken into consideration.

Metabolic neural mapping in neonatal rats

International Nuclear Information System (INIS)

DiRocco, R.J.; Hall, W.G.

1981-01-01

Functional neural mapping by 14 C-deoxyglucose autoradiography in adult rats has shown that increases in neural metabolic rate that are coupled to increased neurophysiological activity are more evident in axon terminals and dendrites than neuron cell bodies. Regions containing architectonically well-defined concentrations of terminals and dendrites (neuropil) have high metabolic rates when the neuropil is physiologically active. In neonatal rats, however, we find that regions containing well-defined groupings of neuron cell bodies have high metabolic rates in 14 C-deoxyglucose autoradiograms. The striking difference between the morphological appearance of 14 C-deoxyglucose autoradiograms obtained from neonatal and adult rats is probably related to developmental changes in morphometric features of differentiating neurons, as well as associated changes in type and locus of neural work performed

Rodent neonatal germinal matrix hemorrhage mimics the human brain injury, neurological consequences, and post-hemorrhagic hydrocephalus

OpenAIRE

Lekic, Tim; Manaenko, Anatol; Rolland, William; Krafft, Paul R.; Peters, Regina; Hartman, Richard E.; Altay, Orhan; Tang, Jiping; Zhang, John H.

2012-01-01

Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns. GMH causes neurological sequelae such as cerebral palsy, post-hemorrhagic hydrocephalus, and mental retardation. Despite this, there is no standardized animal model of spontaneous GMH using newborn rats to depict the condition. We asked whether stereotactic injection of collagenase type VII (0.3 U) into the ganglionic eminence of neonatal rats would reproduce the acute brain injury, gliosis, hydroc...

Magnetic resonance imaging of neonatal brain. Assessment of normal and abnormal findings

International Nuclear Information System (INIS)

Hasegawa, Koh; Kadono, Naoko; Kawase, Shohji; Kihara, Minako; Matsuo, Yasutaka; Yoshioka, Hiroshi; Kinugasa, Akihiko; Sawada, Tadashi

1994-01-01

To establish the normal MRI appearance of the neonatal brain, magnetic resonance imaging (MRI) was performed on 124 neonates who admitted to our neonatal intensive care unit. Degree of myelination, ventricular size, width of the extracerebral space and focal lesion in the brain were evaluated to investigate the relationship between MRI findings of neonatal brain and the neurological prognosis. 85 neonates underwent MRI both at neonatal period and at the corrected age of one year. The change of abnormal MRI findings was evaluated. 19 neonates had abnormal neurological outcome on subsequent examinations. Delayed myelination, ventriculomegaly and large extracerebral space were seen in 13, 7 and 9 neonates respectively. 4, 3 and 5 neonates out of them showed abnormal neurological prognosis respectively. Of the 19 neonates with focal lesion in MRI, 2 had parenchymal hematoma in the brain, 2 had subdural hematoma, 5 had chronic hematoma following subependymal hemorrhage, 6 had cystic formation following subependymal hemorrhage, 2 had subcortical leukomalacia, one had periventricular leukomalacia and one had cyst in the parenchyma of cerebellum. 4 neonates of 19 with focal lesion in MRI showed abnormal development. Of the neonates who had abnormal neurological prognosis, 7 neonates showed no abnormal finding in MRI at neonatal period. 3 of them had mild mental retardation. MRI shows promise in the neonatal period. It facilitates recognition of abnormalities of neonatal brain and may be used to predict abnormal neurologic outcome. However physiological change in the brain of neonates, especially of premature neonates, should be considered on interpreting these findings. Awareness of developmental features should help to minimize misinterpretation of normal changes in the neonatal brain. (author)

Magnetic resonance imaging of neonatal brain. Assessment of normal and abnormal findings

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Koh; Kadono, Naoko; Kawase, Shohji; Kihara, Minako; Matsuo, Yasutaka; Yoshioka, Hiroshi; Kinugasa, Akihiko; Sawada, Tadashi (Kyoto Prefectural Univ. of Medicine (Japan))

1994-11-01

To establish the normal MRI appearance of the neonatal brain, magnetic resonance imaging (MRI) was performed on 124 neonates who admitted to our neonatal intensive care unit. Degree of myelination, ventricular size, width of the extracerebral space and focal lesion in the brain were evaluated to investigate the relationship between MRI findings of neonatal brain and the neurological prognosis. 85 neonates underwent MRI both at neonatal period and at the corrected age of one year. The change of abnormal MRI findings was evaluated. 19 neonates had abnormal neurological outcome on subsequent examinations. Delayed myelination, ventriculomegaly and large extracerebral space were seen in 13, 7 and 9 neonates respectively. 4, 3 and 5 neonates out of them showed abnormal neurological prognosis respectively. Of the 19 neonates with focal lesion in MRI, 2 had parenchymal hematoma in the brain, 2 had subdural hematoma, 5 had chronic hematoma following subependymal hemorrhage, 6 had cystic formation following subependymal hemorrhage, 2 had subcortical leukomalacia, one had periventricular leukomalacia and one had cyst in the parenchyma of cerebellum. 4 neonates of 19 with focal lesion in MRI showed abnormal development. Of the neonates who had abnormal neurological prognosis, 7 neonates showed no abnormal finding in MRI at neonatal period. 3 of them had mild mental retardation. MRI shows promise in the neonatal period. It facilitates recognition of abnormalities of neonatal brain and may be used to predict abnormal neurologic outcome. However physiological change in the brain of neonates, especially of premature neonates, should be considered on interpreting these findings. Awareness of developmental features should help to minimize misinterpretation of normal changes in the neonatal brain. (author).

Renal inflammatory response to urinary tract infection in rat neonates.

Science.gov (United States)

Zarepour, M; Moradpoor, H; Emamghorashi, F; Owji, S M; Roodaki, M; Khamoushi, M

2015-09-01

Urinary tract infection (UTI) is one of the most common bacterial infections. Maternal UTI is a risk factor for neonatal UTI. The aim of the present study was to determine the severity of renal inflammation in neonate rats born from mothers with induced UTI. Twelve pregnant rats (Sprague-Dawley) were included in study. The rats were divided into two groups (six rats in each group). In the first group, pyelonephritis was induced in the third trimester of pregnancy and the second group was used as a control group. After delivery, the neonates were divided into three groups based on days after birth (the 1 st, 3 rd and 7 th days after birth). In each group, two neonates of each mother were killed and a midline abdominal incision was made and both kidneys were aseptically removed. On the 7 th day, rat mothers were killed and their kidneys were removed. The preparations were evaluated with a bright field microscope for inflammatory response. Renal pathology showed inflammation in all UTI-induced mothers, but only two cases of neonates (2.1%) showed inflammation in the renal parenchyma. There was no relation between the positive renal culture and the pathological changes. We conclude that neonates with UTI born to UTI-induced mothers showed a lesser inflammatory response.

Rodent neonatal germinal matrix hemorrhage mimics the human brain injury, neurological consequences, and post-hemorrhagic hydrocephalus.

Science.gov (United States)

Lekic, Tim; Manaenko, Anatol; Rolland, William; Krafft, Paul R; Peters, Regina; Hartman, Richard E; Altay, Orhan; Tang, Jiping; Zhang, John H

2012-07-01

Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns. GMH causes neurological sequelae such as cerebral palsy, post-hemorrhagic hydrocephalus, and mental retardation. Despite this, there is no standardized animal model of spontaneous GMH using newborn rats to depict the condition. We asked whether stereotactic injection of collagenase type VII (0.3 U) into the ganglionic eminence of neonatal rats would reproduce the acute brain injury, gliosis, hydrocephalus, periventricular leukomalacia, and attendant neurological consequences found in humans. To test this hypothesis, we used our neonatal rat model of collagenase-induced GMH in P7 pups, and found that the levels of free-radical adducts (nitrotyrosine and 4-hyroxynonenal), proliferation (mammalian target of rapamycin), inflammation (COX-2), blood components (hemoglobin and thrombin), and gliosis (vitronectin and GFAP) were higher in the forebrain of GMH pups, than in controls. Neurobehavioral testing showed that pups with GMH had developmental delay, and the juvenile animals had significant cognitive and motor disability, suggesting clinical relevance of the model. There was also evidence of white-matter reduction, ventricular dilation, and brain atrophy in the GMH animals. This study highlights an instructive animal model of the neurological consequences after germinal matrix hemorrhage, with evidence of brain injuries that can be used to evaluate strategies in the prevention and treatment of post-hemorrhagic complications. Copyright © 2012 Elsevier Inc. All rights reserved.

The neurological effects of brevetoxin on neonatal rats

Energy Technology Data Exchange (ETDEWEB)

Tapley, S.R.; Ramsdell, J.S.; Xi, D. [Medical Univ. of South Carolina, Charleston, SC (United States)] [and others

1994-12-31

We have investigated the neuroexcitatory and neurodegenerative effects of brevetoxin on neonatal rats. Brevetoxin, a marine-biotoxin that has been implicated in several seafood poisoning incidents, is produced by the dinoflagellate Gymnodinium brevis. Four studies were done: dose response, northern analysis, immunohistochemistry and neurodegeneration. We found that neonatal rats are much more sensitive to brevetoxin than adult rats. The effectiveness of c-fos as a biomarker is being investigated, because of the high basal expression in young animals. The neurodegeneration, although not available yet, should provide valuable information.

Multidimensional MRI-CT atlas of the naked mole-rat brain (Heterocephalus glaber).

Science.gov (United States)

Seki, Fumiko; Hikishima, Keigo; Nambu, Sanae; Okanoya, Kazuo; Okano, Hirotaka J; Sasaki, Erika; Miura, Kyoko; Okano, Hideyuki

2013-01-01

Naked mole-rats have a variety of distinctive features such as the organization of a hierarchical society (known as eusociality), extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI). Advanced MRI techniques such as diffusion tensor imaging (DTI), which generates high contrast images of fiber structures, can characterize unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D) images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualization of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

Renal inflammatory response to urinary tract infection in rat neonates

Directory of Open Access Journals (Sweden)

M Zarepour

2015-01-01

Full Text Available Urinary tract infection (UTI is one of the most common bacterial infections. Maternal UTI is a risk factor for neonatal UTI. The aim of the present study was to determine the severity of renal inflammation in neonate rats born from mothers with induced UTI. Twelve pregnant rats (Sprague-Dawley were included in study. The rats were divided into two groups (six rats in each group. In the first group, pyelonephritis was induced in the third trimester of pregnancy and the second group was used as a control group. After delivery, the neonates were divided into three groups based on days after birth (the 1 st, 3 rd and 7 th days after birth. In each group, two neonates of each mother were killed and a midline abdominal incision was made and both kidneys were aseptically removed. On the 7 th day, rat mothers were killed and their kidneys were removed. The preparations were evaluated with a bright field microscope for inflammatory response. Renal pathology showed inflammation in all UTI-induced mothers, but only two cases of neonates (2.1% showed inflammation in the renal parenchyma. There was no relation between the positive renal culture and the pathological changes. We conclude that neonates with UTI born to UTI-induced mothers showed a lesser inflammatory response.

The effects of a single memantine treatment on behavioral alterations associated with binge alcohol exposure in neonatal rats.

Science.gov (United States)

Idrus, Nirelia M; McGough, Nancy N H; Spinetta, Michael J; Thomas, Jennifer D; Riley, Edward P

2011-01-01

The third trimester in human fetal development represents a critical time of brain maturation referred to as the "brain growth spurt". This period occurs in rats postnatally, and exposure to ethanol during this time can increase the risk of impairments on a variety of cognitive and motor tasks. It has been proposed that one potential mechanism for the teratogenic effects of ethanol is NMDA receptor-mediated excitotoxicity during periods of ethanol withdrawal. In neonatal rats, antagonism of NMDA receptors during ethanol withdrawal, with drugs such as MK-801 and eliprodil, has been shown to mitigate some of the behavioral deficits induced by developmental ethanol exposure. The current study examined whether memantine, an NMDA receptor antagonist and a drug used clinically in Alzheimer's patients, would attenuate impairments associated with binge ethanol exposure in neonatal rats. On postnatal day 6, rats were exposed to 6 g/kg ethanol via intubation with controls receiving an isocaloric maltose dextrin solution. Twenty-one hours following the ethanol binge, rats received intraperitoneal injections of memantine at 0, 10, 15, or 20 mg/kg. Ethanol's teratogenic effects were assessed using multiple behavioral tasks: open field activity, parallel bars and spatial discrimination reversal learning. Ethanol-treated rats were overactive in the open field and were impaired on both reversal learning and motor performance. Administration of 15 or 20 mg/kg memantine during withdrawal significantly attenuated ethanol's adverse effects on motor coordination, but did not significantly alter activity levels or improve the spatial learning deficits associated with neonatal alcohol exposure. These results indicate that a single memantine administration during ethanol withdrawal can mitigate motor impairments but not spatial learning impairments or overactivity observed following a binge ethanol exposure during development in the rat. Copyright © 2011 Elsevier Inc. All rights reserved.

Susceptibility weighted imaging of the neonatal brain

International Nuclear Information System (INIS)

Meoded, A.; Poretti, A.; Northington, F.J.; Tekes, A.; Intrapiromkul, J.; Huisman, T.A.G.M.

2012-01-01

Susceptibility weighted imaging (SWI) is a well-established magnetic resonance technique, which is highly sensitive for blood, iron, and calcium depositions in the brain and has been implemented in the routine clinical use in both children and neonates. SWI in neonates might provide valuable additional diagnostic and prognostic information for a wide spectrum of neonatal neurological disorders. To date, there are few articles available on the application of SWI in neonatal neurological disorders. The purpose of this article is to illustrate and describe the characteristic SWI findings in various typical neonatal neurological disorders.

Susceptibility weighted imaging of the neonatal brain

Energy Technology Data Exchange (ETDEWEB)

Meoded, A.; Poretti, A. [Division of Pediatric Radiology and Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Northington, F.J. [Division of Neonatology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tekes, A.; Intrapiromkul, J. [Division of Pediatric Radiology and Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Huisman, T.A.G.M., E-mail: thuisma1@jhmi.edu [Division of Pediatric Radiology and Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD (United States)

2012-08-15

Susceptibility weighted imaging (SWI) is a well-established magnetic resonance technique, which is highly sensitive for blood, iron, and calcium depositions in the brain and has been implemented in the routine clinical use in both children and neonates. SWI in neonates might provide valuable additional diagnostic and prognostic information for a wide spectrum of neonatal neurological disorders. To date, there are few articles available on the application of SWI in neonatal neurological disorders. The purpose of this article is to illustrate and describe the characteristic SWI findings in various typical neonatal neurological disorders.

[Mechanism of potassium channel in hypoxia-ischemic brain edema: experiment with neonatal rat astrocyte].

Science.gov (United States)

Fu, Xue-mei; Xiang, Long; Liao, Da-qing; Feng, Zhi-chun; Mu, De-zhi

2008-11-04

To investigate the mechanism of potassium channel in brain edema caused by hypoxia-ischemia (HI). Astrocytes were obtained from 3-day-old SD rats, cultured, and randomly divided into 2 groups: normoxia group, cultured under normoxic condition, and hypoxic-ischemic group, cultured under hypoxic-ischemic condition. The cell volume was measured by radiologic method. Patch-clamp technique was used to observe the electric physiological properties of the voltage-gated potassium channels (Kv) in a whole cell configuration, and the change of voltage-gated potassium channel current (IKv) was recorded in cultured neonatal rat astrocyte during HI. Aquaporin 4 (AQP4) expression vector was constructed from pSUPER vector and transfected into the astrocytes (AQP4 RNAi) to construct AQP4 knockdown (AQP4-/-) cells. cellular volume was determined using [3H]-3-O-methyl-D-glucose uptake in both AQP4-/- and AQP4+/+ cells under the condition of HI. Real time PCR and Western blotting were used to detect the mRNA and protein expression of AQP4. The percentages of the AQP4+/+ and AQP4-/- astrocyte volumes in the condition of HI for 0.5, 1, 2, and 4 h were 104+/-7, 109+/-6, 126+/-12, and 152+/-9 times, and 97+/-7, 105+/-9, 109+/-7, and 132+/-6 times as those of their corresponding control groups (all Pastrocytes significantly increased during HI and the degrees of edema mediated by AQP4 knockdown at different time points were all significantly milder (all Pastrocytes via aquaporin-4 and then cell swelling.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

Directory of Open Access Journals (Sweden)

R.L. Figueira

2016-01-01

Full Text Available Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC. This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group: 1 preterm control (PTC, 2 preterm ventilated (PTV, 3 preterm asphyxiated (PTA, 4 preterm asphyxiated and ventilated (PTAV, 5 term control (TC, 6 term ventilated (TV, 7 term asphyxiated (TA, and 8 term asphyxiated and ventilated (TAV. We measured body, brain, and intestine weights and respective ratios [(BW, (BrW, (IW, (BrW/BW and (IW/BW]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus and intestine (jejunum/ileum tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP. IW was lower in the TA than in the other terms (P<0.05, and the IW/BW ratio was lower in the TA than in the TAV (P<0.005. PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex and TA (cortex/hippocampus (P<0.005. I-FABP was higher in PTAV (P<0.005 and TA (ileum (P<0.05. I-FABP expression was increased in PTAV subgroup (P<0.0001. Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

Endogenous IL-6 of mesenchymal stem cell improves behavioral outcome of hypoxic-ischemic brain damage neonatal rats by supressing apoptosis in astrocyte.

Science.gov (United States)

Gu, Yan; He, Mulan; Zhou, Xiaoqin; Liu, Jinngjing; Hou, Nali; Bin, Tan; Zhang, Yun; Li, Tingyu; Chen, Jie

2016-01-14

Mesenchymal stem cell (MSC) transplantation reduces the neurological impairment caused by hypoxic-ischemic brain damage (HIBD) via immunomodulation. In the current study, we found that MSC transplantation improved learning and memory function and enhanced long-term potentiation in neonatal rats subjected to HIBD and the amount of IL-6 released from MSCs was far greater than that of other cytokines. However, the neuroprotective effect of MSCs infected with siIL-6-transduced recombinant lentivirus (siIL-6 MSCs) was significantly weakened in the behavioural tests and electrophysiological analysis. Meanwhile, the hippocampal IL-6 levels were decreased following siIL-6 MSC transplantation. In vitro, the levels of IL-6 release and the levels of IL-6R and STAT3 expression were increased in both primary neurons and astrocytes subjected to oxygen and glucose deprivation (OGD) following MSCs co-culture. The anti-apoptotic protein Bcl-2 was upregulated and the pro-apoptotic protein Bax was downregulated in OGD-injured astrocytes co-cultured with MSCs. However, the siIL-6 MSCs suppressed ratio of Bcl-2/Bax in the injured astrocytes and induced apoptosis number of the injured astrocytes. Taken together, these data suggest that the neuroprotective effect of MSC transplantation in neonatal HIBD rats is partly mediated by IL-6 to enhance anti-apoptosis of injured astrocytes via the IL-6/STAT3 signaling pathway.

Normal lactate concentration range in the neonatal brain.

Science.gov (United States)

Tomiyasu, Moyoko; Aida, Noriko; Shibasaki, Jun; Tachibana, Yasuhiko; Endo, Mamiko; Nozawa, Kumiko; Shimizu, Eiji; Tsuji, Hiroshi; Obata, Takayuki

2016-11-01

Lactate peaks are occasionally observed during in vivo magnetic resonance spectroscopy (MRS) scans of the neonatal brain, even in healthy patients. The purpose of this study was to investigate the normal range of neonatal brain lactate concentration, as a definitive normal range would be clinically valuable. Using a clinical 3T scanner (echo/repetition times, 30/5000ms), single-voxel MRS data were obtained from the basal ganglia (BG) and centrum semiovale (CS) in 48 healthy neonates (postconceptional age (PCA), 30-43weeks), nine infants (age, 1-12months old), and 20 children (age, 4-15years). Lactate concentrations were calculated using an MRS signal quantification program, LCModel. Correlations between regional lactate concentration and PCA (neonates), or age (all subjects) were investigated. Absolute lactate concentrations of the BG and CS were as follows: neonates, 0.77mM (0-2.02) [median (range)] and 0.77 (0-1.42), respectively; infants, 0.38 (0-0.79) and 0.49 (0.17-1.17); and children, 0.17 (0-0.76) and 0.22 (0-0.80). Overall, subjects' lactate concentrations decreased significantly with age (Spearman: BG, n=61, ρ=-0.38, p=0.003; CS, n=68, ρ=-0.57, p<0.001). However, during the neonatal period no correlations were detected between lactate concentration in either region and PCA. We determined normal ranges of neonatal lactate concentration, which may prove useful for diagnostic purposes. Further studies regarding changes in brain lactate concentration during development would help clarify the reasons for higher concentrations observed during the neonatal period, and contribute to improvements in diagnoses. Copyright © 2016 Elsevier Inc. All rights reserved.

Immunoreactive erythropoietin concentrations in neonatal rats and the effects of hypoxia

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Clemons, G.K.; Fitzsimmons, S.L.; DeManincor, D.

1987-01-01

We attempted to find answers to what are the circulating, hepatic and renal erythropoietin (Ep) levels in normal rat neonates measured daily through the first three weeks of life and when they attain sexual maturity, how are these Ep levels altered by exposure to hypoxia, and whether can it be transferred to the nursing neonatal animals? Since we established earlier that in the fetal rat the liver is the main Ep producing tissue, we attempted to determine the age at which the switch from liver to kidney occurred in both the normal and the hypoxic neonatal rat. 2 figs

Distribution and retention of organic and inorganic mercury in methyl mercury-treated neonatal rats

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Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Hall, L.L.; Mushak, P.

1988-01-01

Seven-day-old Long Evans rats received one mumol of 203 Hg-labeled methyl mercury/kg sc and whole body retention and tissue distribution of organic and inorganic mercury were examined for 32 days postdosing. Neonates cleared mercury slowly until 10 days postdosing when the clearance rate abruptly increased. During the interval when whole body clearance of mercury was extremely slow, methyl mercury was metabolized to inorganic mercury. Peak concentration of mercury in kidney occurred at 2 days postdosing. At 32 days postdosing, 8% of mercury in kidney was in an organic from. Liver mercury concentration peaked at 2 days postdosing and organic mercury accounted for 38% at 32 days postdosing. Brain concentrations of mercury peaked at 2 days postdosing. At 10 days postdosing, organic mercury accounted for 86% of the brain mercury burden, and, at 32 days postdosing, for 60%. The percentage of mercury body burden in pelt rose from 30 to 70% between 1 and 10 days postdosing. At 32 days postdosing pelt contained 85% of the body burden of mercury. At all time points, about 95% of mercury in pelt was in an organic form. Compartmental analysis of these data permitted development of a model to describe the distribution and excretion of organic and inorganic mercury in methyl mercury-treated neonatal rats

Antenatal taurine reduces cerebral cell apoptosis in fetal rats with intrauterine growth restriction.

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Liu, Jing; Wang, Xiaofeng; Liu, Ying; Yang, Na; Xu, Jing; Ren, Xiaotun

2013-08-15

From pregnancy to parturition, Sprague-Dawley rats were daily administered a low protein diet to establish a model of intrauterine growth restriction. From the 12(th) day of pregnancy, 300 mg/kg rine was daily added to food until spontaneous delivery occurred. Brain tissues from normal neonatal rats at 6 hours after delivery, neonatal rats with intrauterine growth restriction, and neonatal rats with intrauterine growth restriction undergoing taurine supplement were obtained for further experiments. The terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling assay revealed that the number of apoptotic cells in the brain tissue of neonatal rats with intrauterine growth restriction significantly increased. Taurine supplement in pregnant rats reduced cell apoptosis in brain tissue from neonatal rats with intrauterine growth restriction. nohistochemical staining revealed that taurine supplement increased glial cell line-derived neurotrophic factor expression and decreased caspase-3 expression in the cerebral cortex of intrauterine growth-restricted fetal rats. These results indicate that taurine supplement reduces cell apoptosis through the glial cell line-derived neurotrophic factor-caspase-3 signaling pathway, resulting in a protective effect on the intrauterine growth-restricted fetal rat brain.

Neonate brain disorders

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Xydis, V.

2012-01-01

Full text: Hypoxic-Ischemic insults in the brain of neonates constitute major cause of morbidity and mortality. A wide range of motor, sensory, and cognitive disabilities are observed in this population spanning from slight motor deficits, school difficulties and behavioral problems up to cerebral palsy and mental retardation. Pathologically involved areas characterized by high metabolic demands and therefore with enhanced vulnerability to any reduction or cessation of energy and oxygen supply. Watershed areas of the brain (vascular end zones and vascular border zones) are predominately affected in any adverse event. Radiologic and pathologic appearance of these lesions depends both on the severity of the insult and the maturity of the brain. The dominant pathology observed in preterm neonates is white matter lesions. There are three basic patterns of brain destruction in this population. Periventricular leukomalacia (PVL focal fPVL, diffuse dPVL), germinal matrix haemorrhage (GMH) associated with intraventricular haemorrhage (IVH), and parenchymal haemorrhage (PH). fPVL is characterized by focal necrosis of all cellular elements in the periventricular white matter, resulting in the formation of cysts, and dPVL is characterized by diffuse destruction of the premyelinating oligodendrocytes (pre-OLs) the precursors of mature oligodendroglia cells responsible for the formation of myelin in a later stage. GMH is located beneath germinal matrix layer surrounding the lateral ventricles and can extend into the ventricular system resulting thus to IVH. Finally, PH is located within the parenchyma adjacent to the ventricles and is believed to represent haemorrhagic infarcts following venous drainage compromise. In term or near-term neonates, the top-ographic pattern of injuries involves mainly gray matter structures. Most frequent predilection sites include the cerebral cortex (paracentral lobule, Rolandic area, visual cortex and hippocampus), basal ganglia, thalamus, and

[The influence of interfered circadian rhythm on pregnancy and neonatal rats].

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Chen, Wen-Jun; Sheng, Wen-Jie; Guo, Yin-Hua; Tan, Yong

2015-10-25

The aim of this study was to observe the influence of interfered circadian rhythm on pregnancy of rats and growth of neonatal rats, and to explore the relationship between the interfered circadian rhythm and the changes of melatonin and progesterone. Continuous light was used to inhibit melatonin secretion and therefore the interfered circadian rhythm animal model was obtained. The influence of interfered circadian rhythm on delivery of pregnant rats was observed. Serum was collected from rats during different stages of pregnancy to measure the concentrations of melatonin and progesterone. In order to observe the embryo resorption rate, half of pregnant rats were randomly selected to undergo a laparotomy, and the remainder was used to observe delivery and assess the growth of neonatal rats after delivery. The results showed that the interfered circadian rhythm induced adverse effects on pregnancy outcomes, including an increase of embryo resorption rate and a decrease in the number of live births; inhibited the secretion of melatonin along with decreased serum progesterone level; prolonged the stage of labor, but not the duration of pregnancy; and disturbed the fetal intrauterine growth and the growth of neonatal rats. The results suggest that interfered circadian rhythm condition made by continuous light could make adverse effects on both pregnant rats and neonatal rats. The results of our study may provide a way to modulate pregnant women's circadian rhythm and a possibility of application of melatonin on pregnant women.

Impact of perinatal systemic hypoxic-ischemic injury on the brain of male offspring rats: an improved model of neonatal hypoxic-ischemic encephalopathy in early preterm newborns.

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Yuejun Huang

Full Text Available In this study, we attempted to design a model using Sprague-Dawley rats to better reproduce perinatal systemic hypoxic-ischemic encephalopathy (HIE in early preterm newborns. On day 21 of gestation, the uterus of pregnant rats were exposed and the blood supply to the fetuses of neonatal HIE groups were thoroughly abscised by hemostatic clamp for 5, 10 or 15 min. Thereafter, fetuses were moved from the uterus and manually stimulated to initiate breathing in an incubator at 37 °C for 1 hr in air. We showed that survival rates of offspring rats were decreased with longer hypoxic time. TUNEL staining showed that apoptotic cells were significant increased in the brains of offspring rats from the 10 min and 15 min HIE groups as compared to the offspring rats in the control group at postnatal day (PND 1, but there was no statistical difference between the offspring rats in the 5 min HIE and control groups. The perinatal hypoxic treatment resulted in decreased neurons and increased cleaved caspase-3 protein levels in the offspring rats from all HIE groups at PND 1. Platform crossing times and the percentage of the time spent in the target quadrant of Morris Water Maze test were significantly reduced in the offspring rats of all HIE groups at PND 30, which were associated with decreased brain-derived neurotrophic factor levels and neuronal cells in the hippocampus of offspring rats at PND 35. These data demonstrated that perinatal ischemic injury led to the death of neuronal cells and long-lasting impairment of memory. This model reproduced hypoxic ischemic encephalopathy in early preterm newborns and may be appropriate for investigating therapeutic interventions.

Impact of Perinatal Systemic Hypoxic–Ischemic Injury on the Brain of Male Offspring Rats: An Improved Model of Neonatal Hypoxic–Ischemic Encephalopathy in Early Preterm Newborns

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Xu, Hongwu; Wu, Weizhao; Lai, Xiulan; Ho, Guyu; Ma, Lian; Chen, Yunbin

2013-01-01

In this study, we attempted to design a model using Sprague-Dawley rats to better reproduce perinatal systemic hypoxic-ischemic encephalopathy (HIE) in early preterm newborns. On day 21 of gestation, the uterus of pregnant rats were exposed and the blood supply to the fetuses of neonatal HIE groups were thoroughly abscised by hemostatic clamp for 5, 10 or 15 min. Thereafter, fetuses were moved from the uterus and manually stimulated to initiate breathing in an incubator at 37 °C for 1 hr in air. We showed that survival rates of offspring rats were decreased with longer hypoxic time. TUNEL staining showed that apoptotic cells were significant increased in the brains of offspring rats from the 10 min and 15 min HIE groups as compared to the offspring rats in the control group at postnatal day (PND) 1, but there was no statistical difference between the offspring rats in the 5 min HIE and control groups. The perinatal hypoxic treatment resulted in decreased neurons and increased cleaved caspase-3 protein levels in the offspring rats from all HIE groups at PND 1. Platform crossing times and the percentage of the time spent in the target quadrant of Morris Water Maze test were significantly reduced in the offspring rats of all HIE groups at PND 30, which were associated with decreased brain-derived neurotrophic factor levels and neuronal cells in the hippocampus of offspring rats at PND 35. These data demonstrated that perinatal ischemic injury led to the death of neuronal cells and long-lasting impairment of memory. This model reproduced hypoxic ischemic encephalopathy in early preterm newborns and may be appropriate for investigating therapeutic interventions. PMID:24324800

Melatonin potentiates the anticonvulsant action of phenobarbital in neonatal rats.

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Forcelli, Patrick A; Soper, Colin; Duckles, Anne; Gale, Karen; Kondratyev, Alexei

2013-12-01

Phenobarbital is the most commonly utilized drug for neonatal seizures. However, questions regarding safety and efficacy of this drug make it particularly compelling to identify adjunct therapies that could boost therapeutic benefit. One potential adjunct therapy is melatonin. Melatonin is used clinically in neonatal and pediatric populations, and moreover, it exerts anticonvulsant actions in adult rats. However, it has not been previously evaluated for anticonvulsant effects in neonatal rats. Here, we tested the hypothesis that melatonin would exert anticonvulsant effects, either alone, or in combination with phenobarbital. Postnatal day (P)7 rats were treated with phenobarbital (0-40mg/kg) and/or melatonin (0-80mg/kg) prior to chemoconvulsant challenge with pentylenetetrazole (100mg/kg). We found that melatonin significantly potentiated the anticonvulsant efficacy of phenobarbital, but did not exert anticonvulsant effects on its own. These data provide additional evidence for the further examination of melatonin as an adjunct therapy in neonatal/pediatric epilepsy. Copyright © 2013 Elsevier B.V. All rights reserved.

Stem cells for brain repair in neonatal hypoxia-ischemia.

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Chicha, L; Smith, T; Guzman, R

2014-01-01

Neonatal hypoxic-ischemic insults are a significant cause of pediatric encephalopathy, developmental delays, and spastic cerebral palsy. Although the developing brain's plasticity allows for remarkable self-repair, severe disruption of normal myelination and cortical development upon neonatal brain injury are likely to generate life-persisting sensory-motor and cognitive deficits in the growing child. Currently, no treatments are available that can address the long-term consequences. Thus, regenerative medicine appears as a promising avenue to help restore normal developmental processes in affected infants. Stem cell therapy has proven effective in promoting functional recovery in animal models of neonatal hypoxic-ischemic injury and therefore represents a hopeful therapy for this unmet medical condition. Neural stem cells derived from pluripotent stem cells or fetal tissues as well as umbilical cord blood and mesenchymal stem cells have all shown initial success in improving functional outcomes. However, much still remains to be understood about how those stem cells can safely be administered to infants and what their repair mechanisms in the brain are. In this review, we discuss updated research into pathophysiological mechanisms of neonatal brain injury, the types of stem cell therapies currently being tested in this context, and the potential mechanisms through which exogenous stem cells might interact with and influence the developing brain.

A Single Neonatal Exposure to BMAA in a Rat Model Produces Neuropathology Consistent with Neurodegenerative Diseases

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Laura Louise Scott

2017-12-01

Full Text Available Although cyanobacterial β-N-methylamino-l-alanine (BMAA has been implicated in the development of Alzheimer’s Disease (AD, Parkinson’s Disease (PD and Amyotrophic Lateral Sclerosis (ALS, no BMAA animal model has reproduced all the neuropathology typically associated with these neurodegenerative diseases. We present here a neonatal BMAA model that causes β-amyloid deposition, neurofibrillary tangles of hyper-phosphorylated tau, TDP-43 inclusions, Lewy bodies, microbleeds and microgliosis as well as severe neuronal loss in the hippocampus, striatum, substantia nigra pars compacta, and ventral horn of the spinal cord in rats following a single BMAA exposure. We also report here that BMAA exposure on particularly PND3, but also PND4 and 5, the critical period of neurogenesis in the rodent brain, is substantially more toxic than exposure to BMAA on G14, PND6, 7 and 10 which suggests that BMAA could potentially interfere with neonatal neurogenesis in rats. The observed selective toxicity of BMAA during neurogenesis and, in particular, the observed pattern of neuronal loss observed in BMAA-exposed rats suggest that BMAA elicits its effect by altering dopamine and/or serotonin signaling in rats.

Overweight worsens apoptosis, neuroinflammation and blood-brain barrier damage after hypoxic ischemia in neonatal brain through JNK hyperactivation

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Wu Hsin-Chieh

2011-04-01

Full Text Available Abstract Background Apoptosis, neuroinflammation and blood-brain barrier (BBB damage affect the susceptibility of the developing brain to hypoxic-ischemic (HI insults. c-Jun N-terminal kinase (JNK is an important mediator of insulin resistance in obesity. We hypothesized that neonatal overweight aggravates HI brain damage through JNK hyperactivation-mediated upregulation of neuronal apoptosis, neuroinflammation and BBB leakage in rat pups. Methods Overweight (OF pups were established by reducing the litter size to 6, and control (NF pups by keeping the litter size at 12 from postnatal (P day 1 before HI on P7. Immunohistochemistry and immunoblotting were used to determine the TUNEL-(+ cells and BBB damage, cleaved caspase-3 and poly (ADP-ribose polymerase (PARP, and phospho-JNK and phospho-BimEL levels. Immunofluorescence was performed to determine the cellular distribution of phospho-JNK. Results Compared with NF pups, OF pups had a significantly heavier body-weight and greater fat deposition on P7. Compared with the NF-HI group, the OF-HI group showed significant increases of TUNEL-(+ cells, cleaved levels of caspase-3 and PARP, and ED1-(+ activated microglia and BBB damage in the cortex 24 hours post-HI. Immunofluorescence of the OF-HI pups showed that activated-caspase 3 expression was found mainly in NeuN-(+ neurons and RECA1-(+ vascular endothelial cells 24 hours post-HI. The OF-HI group also had prolonged escape latency in the Morris water maze test and greater brain-volume loss compared with the NF-HI group when assessed at adulthood. Phospho-JNK and phospho-BimEL levels were higher in OF-HI pups than in NF-HI pups immediately post-HI. JNK activation in OF-HI pups was mainly expressed in neurons, microglia and vascular endothelial cells. Inhibiting JNK activity by AS601245 caused more attenuation of cleaved caspase-3 and PARP, a greater reduction of microglial activation and BBB damage post-HI, and significantly reduced brain damage in

Influence of iron on plutonium absorption by the adult and neonatal rat

International Nuclear Information System (INIS)

Sullivan, M.F.; Ruemmler, P.S.; Buschbom, R.L.

1986-01-01

To determine how iron affects plutonium absorption, adult rats were gavaged with 238 Pu nitrate (pH 2) after they had been fed an iron-deficient diet or treated with iron supplements. Neonatal rats born to dams on an iron-deficient diet were also gavaged with 238 Pu. An iron-deficient diet resulted in enhanced 238 Pu absorption both in the adults and in neonates born to iron-deficient dams. Ferric iron increased 238 Pu absorption 12-fold in adult rats; injected iron-dextran reduced that increase; gavaged ferrous iron reduced 238 Pu absorption to one-third of the control value. Rat neonates absorbed 30 to 40 times as much 238 Pu as adults; absorption was lowered in groups that received iron supplements: Iron-dextran caused a 50% reduction; ferric iron, 95%; and ferrous iron, greater than 95%. The results demonstrate an effect of the oxidation state of iron on plutonium absorption in adult rats different from that observed in suckling rats. The results suggest that the high rate of 238 Pu absorption by neonatal animals is due not only to the permeability of their intestines but also to their high demand for iron

Radiation-induced apoptosis in the neonatal and adult rat spinal cord.

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Li, Y Q; Wong, C S

2000-09-01

This study was designed to characterize radiation-induced apoptosis in the spinal cord of the neonatal and young adult rat. Spinal cords (C2-T2) of 1-, 2- and 10-week-old rats were irradiated with a single dose of 8, 18 or 22 Gy. Apoptosis was assessed histologically according to its specific morphological features or by using the TUNEL assay. Cell proliferation was assessed immunohistochemically using BrdU. Identities of cell types undergoing apoptosis were assessed using immunohistochemistry or in situ hybridization using markers for neurons, glial progenitor cells, microglia, oligodendrocytes and astrocytes. The time course of radiation-induced apoptosis in 1- or 2-week-old rat spinal cord was similar to that in the young adult rat spinal cord. A peak response was observed at about 8 h after irradiation, and the apoptosis index returned to the levels in nonirradiated spinal cords at 24 h. The neonatal rat spinal cord demonstrated increased apoptosis compared to the adult. Values for total yield of apoptosis over 24 h induced by 8 Gy in the neonatal rat spinal cord were significantly greater than that in the adult. Immunohistochemistry studies using Leu7, galactocerebroside, Rip and adenomatous polyposis coli tumor suppressor protein indicated that most apoptotic cells were cells of the oligodendroglial lineage regardless of the age of the animal. No evidence of Gfap or factor VIII-related antigen-positive apoptotic cells was observed, and there was a small number of apoptotic microglial cells (lectin-Rca1 positive) in the neonatal and adult rat spinal cord. In the neonatal but not adult rat spinal cord, about 10% of the apoptotic cells appeared to be neurons and were immunoreactive for synaptophysin. Labeling indices (LI) for BrdU in nonirradiated 1- and 2-week-old rat spinal cord were 20.0 and 16.3%, respectively, significantly greater than the LI of 1.0% in the 10-week-old rat spinal cord. At 8 h after a single dose of 8 Gy, 13.4% of the apoptotic cells were

Glucose and Intermediary Metabolism and Astrocyte-Neuron Interactions Following Neonatal Hypoxia-Ischemia in Rat.

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Brekke, Eva; Berger, Hester Rijkje; Widerøe, Marius; Sonnewald, Ursula; Morken, Tora Sund

2017-01-01

Neonatal hypoxia-ischemia (HI) and the delayed injury cascade that follows involve excitotoxicity, oxidative stress and mitochondrial failure. The susceptibility to excitotoxicity of the neonatal brain may be related to the capacity of astrocytes for glutamate uptake. Furthermore, the neonatal brain is vulnerable to oxidative stress, and the pentose phosphate pathway (PPP) may be of particular importance for limiting this kind of injury. Also, in the neonatal brain, neurons depend upon de novo synthesis of neurotransmitters via pyruvate carboxylase in astrocytes to increase neurotransmitter pools during normal brain development. Several recent publications describing intermediary brain metabolism following neonatal HI have yielded interesting results: (1) Following HI there is a prolonged depression of mitochondrial metabolism in agreement with emerging evidence of mitochondria as vulnerable targets in the delayed injury cascade. (2) Astrocytes, like neurons, are metabolically impaired following HI, and the degree of astrocytic malfunction may be an indicator of the outcome following hypoxic and hypoxic-ischemic brain injury. (3) Glutamate transfer from neurons to astrocytes is not increased following neonatal HI, which may imply that astrocytes fail to upregulate glutamate uptake in response to the massive glutamate release during HI, thus contributing to excitotoxicity. (4) In the neonatal brain, the activity of the PPP is reduced following HI, which may add to the susceptibility of the neonatal brain to oxidative stress. The present review aims to discuss the metabolic temporal alterations observed in the neonatal brain following HI.

Hyperleptinemia in Neonatally Overfed Female Rats Does Not Dysregulate Feeding Circuitry

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Ilvana Ziko

2017-10-01

Full Text Available Neonatal overfeeding during the first weeks of life in male rats is associated with a disruption in the peripheral and central leptin systems. Neonatally overfed male rats have increased circulating leptin in the first 2 weeks of life, which corresponds to an increase in body weight compared to normally fed counterparts. These effects are associated with a short-term disruption in the connectivity of neuropeptide Y (NPY, agouti-related peptide (AgRP, and pro-opiomelanocortin (POMC neurons within the regions of the hypothalamus responsible for control of energy balance and food intake. Female rats that are overfed during the first weeks of their life experience similar changes in circulating leptin levels as well as in their body weight. However, it has not yet been studied whether these metabolic changes are associated with the same central effects as observed in males. Here, we hypothesized that hyperleptinemia associated with neonatal overfeeding would lead to changes in central feeding circuitry in females as it does in males. We assessed hypothalamic NPY, AgRP, and POMC gene expression and immunoreactivity at 7, 12, or 14 days of age, as well as neuronal activation in response to exogenous leptin in neonatally overfed and control female rats. Neonatally overfed female rats were hyperleptinemic and were heavier than controls. However, these metabolic changes were not mirrored centrally by changes in hypothalamic NPY, AGRP, and POMC fiber density. These findings are suggestive of sex differences in the effects of neonatal overfeeding and of differences in the ability of the female and male central systems to respond to changes in the early life nutritional environment.

Transport, monitoring, and successful brain MR imaging in unsedated neonates

International Nuclear Information System (INIS)

Mathur, Amit M.; Neil, Jeffrey J.; McKinstry, Robert C.; Inder, Terrie E.

2008-01-01

Neonatal cerebral MR imaging is a sensitive technique for evaluating brain injury in the term and preterm infant. In term encephalopathic infants, MR imaging reliably detects not only the pattern of brain injury but might also provide clues about the timing of injury. In premature infants, MR imaging has surpassed US in the detection of white matter injury, a common lesion in this population. Concerns remain about the safety and transport of sedated neonates for MR examination to radiology suites, which are usually located at a distance from neonatal intensive care units. We present our own institutional experience and guidelines used to optimize the performance of cerebral MR examinations in neonates without sedation or anesthesia. (orig.)

Nitric oxide induces hypoxia ischemic injury in the neonatal brain via the disruption of neuronal iron metabolism.

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Lu, Qing; Harris, Valerie A; Rafikov, Ruslan; Sun, Xutong; Kumar, Sanjiv; Black, Stephen M

2015-12-01

We have recently shown that increased hydrogen peroxide (H2O2) generation is involved in hypoxia-ischemia (HI)-mediated neonatal brain injury. H2O2 can react with free iron to form the hydroxyl radical, through Fenton Chemistry. Thus, the objective of this study was to determine if there was a role for the hydroxyl radical in neonatal HI brain injury and to elucidate the underlying mechanisms. Our data demonstrate that HI increases the deposition of free iron and hydroxyl radical formation, in both P7 hippocampal slice cultures exposed to oxygen-glucose deprivation (OGD), and the neonatal rat exposed to HI. Both these processes were found to be nitric oxide (NO) dependent. Further analysis demonstrated that the NO-dependent increase in iron deposition was mediated through increased transferrin receptor expression and a decrease in ferritin expression. This was correlated with a reduction in aconitase activity. Both NO inhibition and iron scavenging, using deferoxamine administration, reduced hydroxyl radical levels and neuronal cell death. In conclusion, our results suggest that increased NO generation leads to neuronal cell death during neonatal HI, at least in part, by altering iron homeostasis and hydroxyl radical generation. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Phenobarbital and midazolam increase neonatal seizure-associated neuronal injury.

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Torolira, Daniel; Suchomelova, Lucie; Wasterlain, Claude G; Niquet, Jerome

2017-07-01

Status epilepticus is common in neonates and infants, and is associated with neuronal injury and adverse developmental outcomes. γ-Aminobutyric acidergic (GABAergic) drugs, the standard treatment for neonatal seizures, can have excitatory effects in the neonatal brain, which may worsen the seizures and their effects. Using a recently developed model of status epilepticus in postnatal day 7 rat pups that results in widespread neuronal injury, we found that the GABA A agonists phenobarbital and midazolam significantly increased status epilepticus-associated neuronal injury in various brain regions. Our results suggest that more research is needed into the possible deleterious effects of GABAergic drugs on neonatal seizures and on excitotoxic neuronal injury in the immature brain. Ann Neurol 2017;82:115-120. © 2017 American Neurological Association.

Neonatal ischemic brain injury: what every radiologist needs to know

International Nuclear Information System (INIS)

Badve, Chaitra A.; Khanna, Paritosh C.; Ishak, Gisele E.

2012-01-01

We present a pictorial review of neonatal ischemic brain injury and look at its pathophysiology, imaging features and differential diagnoses from a radiologist's perspective. The concept of perinatal stroke is defined and its distinction from hypoxic-ischemic injury is emphasized. A brief review of recent imaging advances is included and a diagnostic approach to neonatal ischemic brain injury is suggested. (orig.)

Neonatal ischemic brain injury: what every radiologist needs to know

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Badve, Chaitra A.; Khanna, Paritosh C.; Ishak, Gisele E. [Seattle Children' s Hospital, University of Washington Medical Center, Department of Radiology, Seattle, WA (United States)

2012-05-15

We present a pictorial review of neonatal ischemic brain injury and look at its pathophysiology, imaging features and differential diagnoses from a radiologist's perspective. The concept of perinatal stroke is defined and its distinction from hypoxic-ischemic injury is emphasized. A brief review of recent imaging advances is included and a diagnostic approach to neonatal ischemic brain injury is suggested. (orig.)

Pharmacokinetics of bisphenol A in neonatal and adult Sprague-Dawley rats

International Nuclear Information System (INIS)

Doerge, Daniel R.; Twaddle, Nathan C.; Vanlandingham, Michelle; Fisher, Jeffrey W.

2010-01-01

Bisphenol A (BPA) is an important industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA in urine of > 90% of Americans aged 6-60 suggests ubiquitous and frequent exposure. The current study used LC/MS/MS to measure serum pharmacokinetics of aglycone (active) and conjugated (inactive) BPA in adult and neonatal Sprague-Dawley rats by oral and injection routes. Deuterated BPA was used to avoid issues of background contamination. Linear pharmacokinetics were observed in adult rats treated orally in the range of 0-200 μg/kg bw. Evidence for enterohepatic recirculation of conjugated, but not aglycone, BPA was observed in adult rats. Significant inverse relationships were observed between postnatal age and measures of internal exposures to aglycone BPA and its elimination. In neonatal rats treated orally, internal exposures to aglycone BPA were substantially lower than from subcutaneous injection. The results reinforce the critical role for first-pass Phase II metabolism of BPA in gut and liver after oral exposure that attenuates internal exposure to the aglycone form in rats of all ages. The internal exposures to aglycone BPA observed in adult and neonatal rats following a single oral dose of 100 μg/kg bw are inconsistent with effects mediated by classical estrogen receptors based on binding affinities. However, an impact on alternative estrogen signaling pathways that have higher receptor affinity cannot be excluded in neonatal rats. These findings emphasize the importance of matching aglycone BPA internal dosimetry with receptor affinities in experimental animal studies reporting toxicity.

Population differences in brain morphology and microstructure among Chinese, Malay, and Indian neonates.

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Bai, Jordan; Abdul-Rahman, Muhammad Farid; Rifkin-Graboi, Anne; Chong, Yap-Seng; Kwek, Kenneth; Saw, Seang-Mei; Godfrey, Keith M; Gluckman, Peter D; Fortier, Marielle V; Meaney, Michael J; Qiu, Anqi

2012-01-01

We studied a sample of 75 Chinese, 73 Malay, and 29 Indian healthy neonates taking part in a cohort study to examine potential differences in neonatal brain morphology and white matter microstructure as a function of ethnicity using both structural T2-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). We first examined the differences in global size and morphology of the brain among the three groups. We then constructed the T2-weighted MRI and DTI atlases and employed voxel-based analysis to investigate ethnic differences in morphological shape of the brain from the T2-weighted MRI, and white matter microstructure measured by fractional anisotropy derived from DTI. Compared with Malay neonates, the brains of Indian neonates' tended to be more elongated in anterior and posterior axis relative to the superior-inferior axis of the brain even though the total brain volume was similar among the three groups. Although most anatomical regions of the brain were similar among Chinese, Malay, and Indian neonates, there were anatomical variations in the spinal-cerebellar and cortical-striatal-thalamic neural circuits among the three populations. The population-related brain regions highlighted in our study are key anatomical substrates associated with sensorimotor functions.

Lymphocytes Contribute to the Pathophysiology of Neonatal Brain Injury

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Arshed Nazmi

2018-03-01

Full Text Available BackgroundPeriventricular leukomalacia (PVL is the most common form of preterm brain injury affecting the cerebral white matter. This type of injury involves a multiphase process and is induced by many factors, including hypoxia–ischemia (HI and infection. Previous studies have suggested that lymphocytes play a significant role in the pathogenesis of brain injury, and the aim of this study was to determine the contribution of lymphocyte subsets to preterm brain injury.MethodsImmunohistochemistry on brain sections from neonatal mice was performed to evaluate the extent of brain injury in wild-type and T cell and B cell-deficient neonatal mice (Rag1−/− mice using a mouse model of HI-induced preterm brain injury. Flow cytometry was performed to determine the presence of different types of immune cells in mouse brains following HI. In addition, immunostaining for CD3 T cells and CD20 B cells was performed on postmortem preterm human infant brains with PVL.ResultsMature lymphocyte-deficient Rag1−/− mice showed protection from white matter loss compared to wild type mice as indicated by myelin basic protein immunostaining of mouse brains. CD3+ T cells and CD20+ B cells were observed in the postmortem preterm infant brains with PVL. Flow cytometry analysis of mouse brains after HI-induced injury showed increased frequency of CD3+ T, αβT and B cells at 7 days after HI in the ipsilateral (injured hemisphere compared to the contralateral (control, uninjured hemisphere.ConclusionLymphocytes were found in the injured brain after injury in both mice and humans, and lack of mature lymphocytes protected neonatal mice from HI-induced brain white matter injury. This finding provides insight into the pathology of perinatal brain injury and suggests new avenues for the development of therapeutic strategies.

Recruitment of hypothalamic orexin neurons after formalin injections in adult male rats exposed to a neonatal immune challenge

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Erin Jane Campbell

2015-03-01

Full Text Available Exposure to early life physiological stressors, such as infection, is thought to contribute to the onset of psychopathology in adulthood. In animal models, injections of the bacterial immune challenge, lipopolysaccharide (LPS, during the neonatal period has been shown to alter both neuroendocrine function and behavioural pain responses in adulthood. Interestingly, recent evidence suggests a role for the lateral hypothalamic peptide orexin in stress and nociceptive processing. However, whether neonatal LPS exposure affects the reactivity of the orexin system to formalin-induced inflammatory pain in later life remains to be determined. Male Wistar rats (n=13 were exposed to either LPS or saline (0.05mg/kg, i.p on postnatal days (PND 3 and 5. On PND 80-97, all rats were exposed to a subcutaneous hindpaw injection of 2.25% formalin. Following behavioural testing, animals were perfused and brains processed for Fos-protein and orexin immunohistochemistry. Rats treated with LPS during the neonatal period exhibited decreased licking behaviours during the interphase of the formalin test, the period typically associated with the active inhibition of pain, and increased grooming responses to formalin in adulthood. Interestingly, these behavioural changes were accompanied by an increase in the percentage of Fos-positive orexin cells in the dorsomedial and perifornical hypothalamus in LPS-exposed animals. Similar increases in Fos-protein were also observed in stress and pain sensitive brain regions that receive orexinergic inputs. These findings highlight a potential role for orexin in the behavioural responses to pain and provide further evidence that early life stress can prime the circuitry responsible for these responses in adulthood.

Cytomegalovirus Infection of the Rat Developing Brain In Utero Prominently Targets Immune Cells and Promotes Early Microglial Activation.

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Robin Cloarec

Full Text Available Congenital cytomegalovirus infections are a leading cause of neurodevelopmental disorders in human and represent a major health care and socio-economical burden. In contrast with this medical importance, the pathophysiological events remain poorly known. Murine models of brain cytomegalovirus infection, mostly neonatal, have brought recent insights into the possible pathogenesis, with convergent evidence for the alteration and possible involvement of brain immune cells.In order to confirm and expand those findings, particularly concerning the early developmental stages following infection of the fetal brain, we have created a model of in utero cytomegalovirus infection in the developing rat brain. Rat cytomegalovirus was injected intraventricularly at embryonic day 15 (E15 and the brains analyzed at various stages until the first postnatal day, using a combination of gene expression analysis, immunohistochemistry and multicolor flow cytometry experiments.Rat cytomegalovirus infection was increasingly seen in various brain areas including the choroid plexi and the ventricular and subventricular areas and was prominently detected in CD45low/int, CD11b+ microglial cells, in CD45high, CD11b+ cells of the myeloid lineage including macrophages, and in CD45+, CD11b- lymphocytes and non-B non-T cells. In parallel, rat cytomegalovirus infection of the developing rat brain rapidly triggered a cascade of pathophysiological events comprising: chemokines upregulation, including CCL2-4, 7 and 12; infiltration by peripheral cells including B-cells and monocytes at E17 and P1, and T-cells at P1; and microglia activation at E17 and P1.In line with previous findings in neonatal murine models and in human specimen, our study further suggests that neuroimmune alterations might play critical roles in the early stages following cytomegalovirus infection of the brain in utero. Further studies are now needed to determine which role, whether favorable or detrimental

Immature rat brain slices exposed to oxygen-glucose deprivation as an in vitro model of neonatal hypoxic-ischemic encephalopathy.

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Fernández-López, David; Martínez-Orgado, José; Casanova, Ignacio; Bonet, Bartolomé; Leza, Juan Carlos; Lorenzo, Pedro; Moro, Maria Angeles; Lizasoain, Ignacio

2005-06-30

To analyze whether exposure to oxygen-glucose deprivation (OGD) of immature rat brain slices might reproduce the main pathophysiologic events leading to neuronal death in neonatal hypoxic-ischemic encephalopathy (NHIE), 500 microm-thick brain slices were obtained from 7-day-old Wistar rats, and incubated in oxygenated physiological solution. In OGD group, oxygen and glucose were removed from the medium for 10-30 min (n = 25); then, slices were re-incubated in normal medium. In control group the medium composition remained unchanged (CG, n = 30). Medium samples were obtained every 30 min for 3 h. To analyze neuronal damage, slices were stained with Nissl and CA1 area of hippocampus and cortex were observed under microscopy. In addition, neuronal death was quantified as LDH released to the medium determined by spectrophotometry. Additionally, medium glutamate (Glu) levels were determined by HPLC and those of TNFalpha by ELISA, whereas inducible nitric oxide synthase expression was determined by Western blot performed on slices homogenate. Optimal OGD time was established in 20 min. After OGD, a significant decrease in the number of neurones in hippocampus and cortex was observed. LDH release was maximal at 30 min, when it was five-fold greater than in CG. Furthermore, medium Glu concentrations were 200 times greater than CG levels at the end of OGD period. A linear relationship between Glu and LDH release was demonstrated. Finally, 3 h after OGD a significant induction of iNOS as well as an increase in TNFalpha release were observed. In conclusion, OGD appears as a feasible and reproducible in vitro model, leading to a neuronal damage, which is physiopathologically similar to that found in NHIE.

Glycogen metabolism in brain and neurons - astrocytes metabolic cooperation can be altered by pre- and neonatal lead (Pb) exposure.

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Baranowska-Bosiacka, Irena; Falkowska, Anna; Gutowska, Izabela; Gąssowska, Magdalena; Kolasa-Wołosiuk, Agnieszka; Tarnowski, Maciej; Chibowska, Karina; Goschorska, Marta; Lubkowska, Anna; Chlubek, Dariusz

2017-09-01

Lead (Pb) is an environmental neurotoxin which particularly affects the developing brain but the molecular mechanism of its neurotoxicity still needs clarification. The aim of this paper was to examine whether pre- and neonatal exposure to Pb (concentration of Pb in rat offspring blood below the "threshold level") may affect the brain's energy metabolism in neurons and astrocytes via the amount of available glycogen. We investigated the glycogen concentration in the brain, as well as the expression of the key enzymes involved in glycogen metabolism in brain: glycogen synthase 1 (Gys1), glycogen phosphorylase (PYGM, an isoform active in astrocytes; and PYGB, an isoform active in neurons) and phosphorylase kinase β (PHKB). Moreover, the expression of connexin 43 (Cx43) was evaluated to analyze whether Pb poisoning during the early phase of life may affect the neuron-astrocytes' metabolic cooperation. This work shows for the first time that exposure to Pb in early life can impair brain energy metabolism by reducing the amount of glycogen and decreasing the rate of its metabolism. This reduction in brain glycogen level was accompanied by a decrease in Gys1 expression. We noted a reduction in the immunoreactivity and the gene expression of both PYGB and PYGM isoform, as well as an increase in the expression of PHKB in Pb-treated rats. Moreover, exposure to Pb induced decrease in connexin 43 immunoexpression in all the brain structures analyzed, both in astrocytes as well as in neurons. Our data suggests that exposure to Pb in the pre- and neonatal periods results in a decrease in the level of brain glycogen and a reduction in the rate of its metabolism, thereby reducing glucose availability, which as a further consequence may lead to the impairment of brain energy metabolism and the metabolic cooperation between neurons and astrocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of hyperbaric oxygenation on mitochondrial function of neuronal cells in the cortex of neonatal rats after hypoxic-ischemic brain damage

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L. Yang

2016-01-01

Full Text Available The timing and mechanisms of protection by hyperbaric oxygenation (HBO in hypoxic-ischemic brain damage (HIBD have only been partially elucidated. We monitored the effect of HBO on the mitochondrial function of neuronal cells in the cerebral cortex of neonatal rats after HIBD. Neonatal Sprague-Dawley rats (total of 360 of both genders were randomly divided into normal control, HIBD, and HIBD+HBO groups. The HBO treatment began immediately after hypoxia-ischemia (HI and continued once a day for 7 consecutive days. Animals were euthanized 0, 2, 4, 6, and 12 h post-HI to monitor the changes in mitochondrial membrane potential (ΔΨm occurring soon after a single dose of HBO treatment, as well as 2, 3, 4, 5, 6, and 7 days post-HI to study ΔΨm changes after a series of HBO treatments. Fluctuations in ΔΨm were observed in the ipsilateral cortex in both HIBD and HIBD+HBO groups. Within 2 to 12 h after HI insult, the ΔΨm of the HIBD and HIBD+HBO groups recovered to some extent. A secondary drop in ΔΨm was observed in both groups during the 1-4 days post-HI period, but was more severe in the HIBD+HBO group. There was a secondary recovery of ΔΨm observed in the HIBD+HBO group, but not in the HIBD group, during the 5-7 days period after HI insult. HBO therapy may not lead to improvement of neural cell mitochondrial function in the cerebral cortex in the early stage post-HI, but may improve it in the sub-acute stage post-HI.

Neonatal morphine enhances nociception and decreases analgesia in young rats.

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Zhang, Guo Hua; Sweitzer, Sarah M

2008-03-14

The recognition of the impact of neonatal pain experience on subsequent sensory processing has led to the increased advocacy for the use of opioids for pain relief in infants. However, following long-term opioid exposure in intensive care units more than 48% of infants exhibited behaviors indicative of opioid abstinence syndrome, a developmentally equivalent set of behaviors to opioid withdrawal as seen in adults. Little is known about the long-term influence of repeated neonatal morphine exposure on nociception and analgesia. To investigate this, we examined mechanical and thermal nociception on postnatal days 11, 13, 15, 19, 24, 29, 39 and 48 following subcutaneous administration of morphine (3 mg/kg) once daily on postnatal days 1-9. The cumulative morphine dose-response was assessed on postnatal days 20 and 49, and stress-induced analgesia was assessed on postnatal days 29 and 49. Both basal mechanical and thermal nociception in neonatal, morphine-exposed rats were significantly lower than those in saline-exposed, handled-control rats and naive rats until P29. A rightward-shift of cumulative dose-response curves for morphine analgesia upon chronic neonatal morphine was observed both on P20 and P49. The swim stress-induced analgesia was significantly decreased in neonatal morphine-exposed rats on P29, but not on P49. These data indicate that morphine exposure equivalent to the third trimester of gestation produced prolonged pain hypersensitivity, decreased morphine antinociception, and decreased stress-induced analgesia. The present study illustrates the need to examine the long-term influence of prenatal morphine exposure on pain and analgesia in the human pediatric population.

Neonatal programming with testosterone propionate reduces dopamine transporter expression in nucleus accumbens and methylphenidate-induced locomotor activity in adult female rats.

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Dib, Tatiana; Martínez-Pinto, Jonathan; Reyes-Parada, Miguel; Torres, Gonzalo E; Sotomayor-Zárate, Ramón

2018-07-02

Research in programming is focused on the study of stimuli that alters sensitive periods in development, such as prenatal and neonatal stages, that can produce long-term deleterious effects. These effects can occur in various organs or tissues such as the brain, affecting brain circuits and related behaviors. Our laboratory has demonstrated that neonatal programming with sex hormones affects the mesocorticolimbic circuitry, increasing the synthesis and release of dopamine (DA) in striatum and nucleus accumbens (NAcc). However, the behavioral response to psychostimulant drugs such as methylphenidate and the possible mechanism(s) involved have not been studied in adult rats exposed to sex hormones during the first hours of life. Thus, the aim of this study was to examine the locomotor activity induced by methylphenidate (5mg/kg i.p.) and the expression of the DA transporter (DAT) in NAcc of adult rats exposed to a single dose of testosterone propionate (TP: 1mg/50μLs.c.) or estradiol valerate (EV: 0.1mg/50μLs.c.) at postnatal day 1. Our results demonstrated that adult female rats treated with TP have a lower methylphenidate-induced locomotor activity compared to control and EV-treated adult female rats. This reduction in locomotor activity is related with a lower NAcc DAT expression. However, neither methylphenidate-induced locomotor activity nor NAcc DAT expression was affected in EV or TP-treated adult male rats. Our results suggest that early exposure to sex hormones affects long-term dopaminergic brain areas involved in the response to psychostimulants, which could be a vulnerability factor to favor the escalating doses of drugs of abuse. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular Mechanisms of Neonatal Brain Injury

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Claire Thornton

2012-01-01

Full Text Available Fetal/neonatal brain injury is an important cause of neurological disability. Hypoxia-ischemia and excitotoxicity are considered important insults, and, in spite of their acute nature, brain injury develops over a protracted time period during the primary, secondary, and tertiary phases. The concept that most of the injury develops with a delay after the insult makes it possible to provide effective neuroprotective treatment after the insult. Indeed, hypothermia applied within 6 hours after birth in neonatal encephalopathy reduces neurological disability in clinical trials. In order to develop the next generation of treatment, we need to know more about the pathophysiological mechanism during the secondary and tertiary phases of injury. We review some of the critical molecular events related to mitochondrial dysfunction and apoptosis during the secondary phase and report some recent evidence that intervention may be feasible also days-weeks after the insult.

Brain death in neonates: a case report

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Georgios Mitsiakos

2014-06-01

Full Text Available Brain death (BD is the permanent and complete loss of cerebral and brainstem function. It is relatively uncommon in newborns with its percentage among deaths being 1-6.3%. BD leads to debate for medical, ethical and philosophical issues. It is a challenging condition in neonatal intensive care units (NICUs since difficulties for BD diagnosis in neonates and ever more so in preterm neonates do arise. Revised guidelines for BD diagnosis definition include history with known etiology, clinical examination, apnea testing and neurological evaluation often assisted by ancillary tests. We present the case of a near term female baby that was born with brain death due to hypoxic ischemic encephalopathy. We conclude that BD in newborns is a challenge to NICUs and there is a need for establishing and implementing new guidelines and checklists on national basis. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in Neonatology Guest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

Identification of Transmembrane Protease Serine 2 and Forkhead Box A1 As the Potential Bisphenol A Responsive Genes in the Neonatal Male Rat Brain

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Takayoshi Ubuka

2018-03-01

Full Text Available Perinatal exposure of Bisphenol A (BPA to rodents modifies their behavior in later life. To understand how BPA modifies their neurodevelopmental process, we first searched for BPA responsive genes from androgen and estrogen receptor signaling target genes by polymerase chain reaction array in the neonatal male rat brain. We used a transgenic strain of Wistar rats carrying enhanced green fluorescent protein tagged to gonadotropin-inhibitory hormone (GnIH promoter to investigate the possible interaction of BPA responsive genes and GnIH neurons. We found upregulation of transmembrane protease serine 2 (Tmprss2, an androgen receptor signaling target gene, and downregulation of Forkhead box A1 (Foxa1, an ER signaling target gene, in the medial amygdala of male rats that were subcutaneously administered with BPA from day 1 to 3. Tmprss2-immunoreactive (ir cells were distributed in the olfactory bulb, cerebral cortex, hippocampus, amygdala, and hypothalamus in 3 days old but not in 1-month-old male rats. Density of Tmprss2-ir cells in the medial amygdala was increased by daily administration of BPA from day 1 to 3. Tmprss2 immunoreactivity was observed in 26.5% of GnIH neurons clustered from the ventral region of the ventromedial hypothalamic nucleus to the dorsal region of the arcuate nucleus of 3-day-old male rat hypothalamus. However, Tmprss2 mRNA expression significantly decreased in the amygdala and hypothalamus of 1-month-old male rats. Foxa1 mRNA expression was higher in the hypothalamus than the amygdala in 3 days old male rats. Intense Foxa1-ir cells were only found in the peduncular part of lateral hypothalamus of 3-day-old male rats. Density of Foxa1-ir cells in the hypothalamus was decreased by daily administration of BPA from day 1 to 3. Foxa1 mRNA expression in the hypothalamus also significantly decreased at 1 month. These results suggest that BPA disturbs the neurodevelopmental process and behavior of rats later in their life by

Programmed Necrosis: A Prominent Mechanism of Cell Death following Neonatal Brain Injury

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Raul Chavez-Valdez

2012-01-01

Full Text Available Despite the introduction of therapeutic hypothermia, neonatal hypoxic ischemic (HI brain injury remains a common cause of developmental disability. Development of rational adjuvant therapies to hypothermia requires understanding of the pathways of cell death and survival modulated by HI. The conceptualization of the apoptosis-necrosis “continuum” in neonatal brain injury predicts mechanistic interactions between cell death and hydrid forms of cell death such as programmed or regulated necrosis. Many of the components of the signaling pathway regulating programmed necrosis have been studied previously in models of neonatal HI. In some of these investigations, they participate as part of the apoptotic pathways demonstrating clear overlap of programmed death pathways. Receptor interacting protein (RIP-1 is at the crossroads between types of cellular death and survival and RIP-1 kinase activity triggers formation of the necrosome (in complex with RIP-3 leading to programmed necrosis. Neuroprotection afforded by the blockade of RIP-1 kinase following neonatal HI suggests a role for programmed necrosis in the HI injury to the developing brain. Here, we briefly review the state of the knowledge about the mechanisms behind programmed necrosis in neonatal brain injury recognizing that a significant proportion of these data derive from experiments in cultured cell and some from in vivo adult animal models. There are still more questions than answers, yet the fascinating new perspectives provided by the understanding of programmed necrosis in the developing brain may lay the foundation for new therapies for neonatal HI.

Brain injuries due to neonatal hypoglycemia: case report

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Kim, Dae Bong; Song, Chang Joon; Chang, Mae Young; Youn, Hyae Won

2003-01-01

Although hypoglycemia may be common among neonates, brain injuries resulting from isolated neonatal hypoglycemia are rare. The condition may cause neurological symptoms such as stupor, jitteriness, and seizures, though in their absence, diagnosis delayed or difficult. Hypoglycemia was diagnosed in a three-day-old neonate after he visited the emergency department with loose stool, poor oral intake, and decreased activity, first experienced two days earlier. Two days after his visity, several episodes of seizure occurred. T2 and diffusion-weighted magnetic resonance (MR) scanning, performed at 11 days of age, revealed bilateral and symmetrical high signal intensity lesions in occipital, parietal, and temporal lobes. We report the MR findings of hypoglycemic encephalopathy in a neonate

Microglial Cells Prevent Hemorrhage in Neonatal Focal Arterial Stroke

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Fernández-López, David; Faustino, Joel; Klibanov, Alexander L.; Derugin, Nikita; Blanchard, Elodie; Simon, Franziska; Leib, Stephen L.; Vexler, Zinaida S.

2016-01-01

Perinatal stroke leads to significant morbidity and long-term neurological and cognitive deficits. The pathophysiological mechanisms of brain damage depend on brain maturation at the time of stroke. To understand whether microglial cells limit injury after neonatal stroke by preserving neurovascular integrity, we subjected postnatal day 7 (P7) rats depleted of microglial cells, rats with inhibited microglial TGFbr2/ALK5 signaling, and corresponding controls, to transient middle cerebral arter...

The role of neonatal NMDA receptor activation in defeminization and masculinization of sex behavior in the rat

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Schwarz, Jaclyn M.; McCarthy, Margaret M.

2008-01-01

Normal development of the male rat brain involves two distinct processes, masculinization and defeminization, that occur during a critical period of brain sexual differentiation. Masculinization allows for the capacity to express male sex behavior in adulthood, and defeminization eliminates or suppresses the capacity to express female sex behavior in adulthood. Despite being separate processes, both masculinization and defeminization are induced by neonatal estradiol exposure. Though the mechanisms underlying estradiol-mediated masculinization of behavior during development have been identified, the mechanisms underlying defeminization are still unknown. We sought to determine whether neonatal activation of glutamate NMDA receptors is a necessary component of estradiol-induced defeminization of behavior. We report here that antagonizing glutamate receptors during the critical period of sexual differentiation blocks estradiol-induced defeminization but not masculinization of behavior in adulthood. However, enhancing NMDA receptor activation during the same critical period mimics estradiol to permanently induce both defeminization and masculinization of sexual behavior. PMID:18687334

KB-R7943 reduces 4-aminopyridine-induced epileptiform activity in adult rats after neuronal damage induced by neonatal monosodium glutamate treatment.

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Hernandez-Ojeda, Mariana; Ureña-Guerrero, Monica E; Gutierrez-Barajas, Paola E; Cardenas-Castillo, Jazmin A; Camins, Antoni; Beas-Zarate, Carlos

2017-05-09

Neonatal monosodium glutamate (MSG) treatment triggers excitotoxicity and induces a degenerative process that affects several brain regions in a way that could lead to epileptogenesis. Na + /Ca 2+ exchangers (NCX1-3) are implicated in Ca 2+ brain homeostasis; normally, they extrude Ca 2+ to control cell inflammation, but after damage and in epilepsy, they introduce Ca 2+ by acting in the reverse mode, amplifying the damage. Changes in NCX3 expression in the hippocampus have been reported immediately after neonatal MSG treatment. In this study, the expression level of NCX1-3 in the entorhinal cortex (EC) and hippocampus (Hp); and the effects of blockade of NCXs on the seizures induced by 4-Aminopyridine (4-AP) were analysed in adult rats after neonatal MSG treatment. KB-R7943 was applied as NCXs blocker, but is more selective to NCX3 in reverse mode. Neonatal MSG treatment was applied to newborn male rats at postnatal days (PD) 1, 3, 5, and 7 (4 g/kg of body weight, s.c.). Western blot analysis was performed on total protein extracts from the EC and Hp to estimate the expression level of NCX1-3 proteins in relative way to the expression of β-actin, as constitutive protein. Electrographic activity of the EC and Hp were acquired before and after intracerebroventricular (i.c.v.) infusion of 4-AP (3 nmol) and KB-R7943 (62.5 pmol), alone or in combination. All experiments were performed at PD60. Behavioural alterations were also recorder. Neonatal MSG treatment significantly increased the expression of NCX3 protein in both studied regions, and NCX1 protein only in the EC. The 4-AP-induced epileptiform activity was significantly higher in MSG-treated rats than in controls, and KB-R7943 co-administered with 4-AP reduced the epileptiform activity in more prominent way in MSG-treated rats than in controls. The long-term effects of neonatal MSG treatment include increases on functional expression of NCXs (mainly of NCX3) in the EC and Hp, which seems to contribute to

Neonatal Brain Tissue Classification with Morphological Adaptation and Unified Segmentation

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Richard eBeare

2016-03-01

Full Text Available Measuring the distribution of brain tissue types (tissue classification in neonates is necessary for studying typical and atypical brain development, such as that associated with preterm birth, and may provide biomarkers for neurodevelopmental outcomes. Compared with magnetic resonance images of adults, neonatal images present specific challenges that require the development of specialized, population-specific methods. This paper introduces MANTiS (Morphologically Adaptive Neonatal Tissue Segmentation, which extends the unified segmentation approach to tissue classification implemented in Statistical Parametric Mapping (SPM software to neonates. MANTiS utilizes a combination of unified segmentation, template adaptation via morphological segmentation tools and topological filtering, to segment the neonatal brain into eight tissue classes: cortical gray matter, white matter, deep nuclear gray matter, cerebellum, brainstem, cerebrospinal fluid (CSF, hippocampus and amygdala. We evaluated the performance of MANTiS using two independent datasets. The first dataset, provided by the NeoBrainS12 challenge, consisted of coronal T2-weighted images of preterm infants (born ≤30 weeks’ gestation acquired at 30 weeks’ corrected gestational age (n= 5, coronal T2-weighted images of preterm infants acquired at 40 weeks’ corrected gestational age (n= 5 and axial T2-weighted images of preterm infants acquired at 40 weeks’ corrected gestational age (n= 5. The second dataset, provided by the Washington University NeuroDevelopmental Research (WUNDeR group, consisted of T2-weighted images of preterm infants (born <30 weeks’ gestation acquired shortly after birth (n= 12, preterm infants acquired at term-equivalent age (n= 12, and healthy term-born infants (born ≥38 weeks’ gestation acquired within the first nine days of life (n= 12. For the NeoBrainS12 dataset, mean Dice scores comparing MANTiS with manual segmentations were all above 0.7, except for

Practical MRI atlas of neonatal brain development

International Nuclear Information System (INIS)

Barkovich, A.J.; Truwit, C.L.

1990-01-01

This book is an anatomical reference for cranial magnetic resonance imaging (MRI) studies in neonates and infants. It contains 122 clear, sharp MRI scans and drawings showing changes in the normal appearance of the brain and skull during development. Sections of the atlas depict the major processes of maturation: brain myelination, development of the corpus callosum, development of the cranial bone marrow, and iron deposition in the brain. High-quality scans illustrate how these changes appear on magnetic resonance images during various stages of development

Serotonin metabolism in rat brain

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Schutte, H.H.

1976-01-01

The metabolism of serotonin in rat brain was studied by measuring specific activities of tryptophan in plasma and of serotonin, 5-hydroxyindole acetic acid and tryptophan in the brain after intravenous injection of tritiated tryptophan. For a detailed analysis of the specific activities, a computer simulation technique was used. It was found that only a minor part of serotonin in rat brain is synthesized from tryptophan rapidly transported from the blood. It is suggested that the brain tryptophan originates from brain proteins. It was also found that the serotonin in rat brain is divided into more than one metabolic compartment

Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia

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2013-01-01

Background Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation and cytokines production in brain injuries; however, its role in hypoxic injury remains uncertain. We investigate here TLR4 expression and its roles in neuroinflammation in neonatal rats following hypoxic injury. Methods One day old Wistar rats were subjected to hypoxia for 2 h. Primary cultured microglia and BV-2 cells were subjected to hypoxia for different durations. TLR4 expression in microglia was determined by RT-PCR, western blot and immunofluorescence staining. Small interfering RNA (siRNA) transfection and antibody neutralization were employed to downregulate TLR4 in BV-2 and primary culture. mRNA and protein expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and inducible nitric oxide synthase (iNOS) was assessed. Reactive oxygen species (ROS), nitric oxide (NO) and NF-κB levels were determined by flow cytometry, colorimetric and ELISA assays respectively. Hypoxia-inducible factor-1 alpha (HIF-1α) mRNA and protein expression was quantified and where necessary, the protein expression was depleted by antibody neutralization. In vivo inhibition of TLR4 with CLI-095 injection was carried out followed by investigation of inflammatory mediators expression via double immunofluorescence staining. Results TLR4 immunofluorescence and protein expression in the corpus callosum and cerebellum in neonatal microglia were markedly enhanced post-hypoxia. In vitro, TLR4 protein expression was significantly increased in both primary microglia and BV-2 cells post-hypoxia. TLR4 neutralization in primary cultured microglia attenuated the hypoxia-induced expression of TNF-α, IL-1β and iNOS. siRNA knockdown of TLR4 reduced hypoxia-induced upregulation of TNF-α, IL-1β, iNOS, ROS and NO in BV-2 cells. TLR4

Astrocyte-derived proinflammatory cytokines induce hypomyelination in the periventricular white matter in the hypoxic neonatal brain.

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Yiyu Deng

Full Text Available Hypoxic exposure in the perinatal period causes periventricular white matter damage (PWMD, a condition associated with myelination abnormalities. Under hypoxic conditions, glial cells were activated and released a large number of inflammatory mediators in the PWM in neonatal brain, which may result in oligodendrocyte (OL loss and axonal injury. This study aims to determine if astrocytes are activated and generate proinflammatory cytokines that may be coupled with the oligodendroglial loss and hypomyelination observed in hypoxic PWMD. Twenty-four 1-day-old Wistar rats were exposed to hypoxia for 2 h. The rats were then allowed to recover under normoxic conditions for 7 or 28 days before being killed. Another group of 24 rats kept outside the chamber was used as age-matched controls. Upregulated expression of TNF-α and IL-1β was observed in astrocytes in the PWM of P7 hypoxic rats by double immunofluorescence, western blotting and real time RT-PCR. This was linked to apoptosis and enhanced expression of TNF-R1 and IL-1R1 in APC(+ OLs. PLP expression was decreased significantly in the PWM of P28d hypoxic rats. The proportion of myelinated axons was markedly reduced by electron microscopy (EM and the average g-ratios were higher in P28d hypoxic rats. Upregulated expression of TNF-α and IL-1β in primary cultured astrocytes as well as their corresponding receptors in primary culture APC(+ oligodendrocytes were detected under hypoxic conditions. Our results suggest that following a hypoxic insult, astrocytes in the PWM of neonatal rats produce inflammatory cytokines such as TNF-α and IL-1β, which induce apoptosis of OLs via their corresponding receptors associated with them. This results in hypomyelination in the PWM of hypoxic rats.

Model of excitation-contraction coupling of rat neonatal ventricular myocytes.

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Korhonen, Topi; Hänninen, Sandra L; Tavi, Pasi

2009-02-01

The neonatal rat ventricular myocyte culture is one of the most popular experimental cardiac cell models. To our knowledge, the excitation-contraction coupling (ECC) of these cells, i.e., the process linking the electrical activity to the cytosolic Ca2+ transient and contraction, has not been previously analyzed, nor has it been presented as a complete system in detail. Neonatal cardiomyocytes are in the postnatal developmental stage, and therefore, the features of their ECC differ vastly from those of adult ventricular myocytes. We present the first complete analysis of ECC in these cells by characterizing experimentally the action potential and calcium signaling and developing the first mathematical model of ECC in neonatal cardiomyocytes that we know of. We show that in comparison to adult cardiomyocytes, neonatal cardiomyocytes have long action potentials, heterogeneous cytosolic Ca2+ signals, weaker sarcoplasmic reticulum Ca2+ handling, and stronger sarcolemmal Ca2+ handling, with a significant contribution by the Na+/Ca2+ exchanger. The developed model reproduces faithfully the ECC of rat neonatal cardiomyocytes with a novel description of spatial cytosolic [Ca2+] signals. Simulations also demonstrate how an increase in the cell size (hypertrophy) affects the ECC in neonatal cardiomyocytes. This model of ECC in developing cardiomyocytes provides a platform for developing future models of cardiomyocytes at different developmental stages.

Melatonin reduces hypoxic-ischaemic (HI) induced autophagy and apoptosis: An in vivo and in vitro investigation in experimental models of neonatal HI brain injury.

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Hu, Yingying; Wang, Zhouguang; Liu, Yanlong; Pan, Shulin; Zhang, Hao; Fang, Mingchu; Jiang, Huai; Yin, Jiayu; Zou, Shuangshuang; Li, Zhenmao; Zhang, Hongyu; Lin, Zhenlang; Xiao, Jian

2017-07-13

Melatonin has neuroprotective effects in many diseases, including neonatal hypoxic-ischaemic (HI) brain injury. The purpose of this study was to evaluate the neuroprotective effects of melatonin both in vivo and in vitro and associated molecular mechanisms behind these effects. Postnatal day 7 male and female rat pups were subjected to unilateral HI, melatonin was injected intraperitoneally 1h before HI and an additional six doses were administered at 24h intervals. The pups were sacrificed at 24h and 7 d after HI. Pre-treatment with melatonin significantly reduced brain damage at 7 d after HI, with 15mg/kg melatonin achieving over 30% recovery in tissue loss compared to vehicle-treated animals. Autophagy and apoptotic cell death as indicated by autophagy associated proteins, cleaved caspase 3 and Tunel staining, was significantly inhibited after melatonin treatment in vivo as well as in PC12 cells. Melatonin treatment also significantly increased the GAP43 in the cortex. In conclusion, melatonin treatment reduced neonatal rat brain injury after HI, and this appeared to be related to inhibiting autophagy as well as reducing apoptotic cell death. Copyright © 2017 Elsevier B.V. All rights reserved.

Dopaminergic differentiation of human neural stem cells mediated by co-cultured rat striatal brain slices

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Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa

2008-01-01

differentiation, we co-cultured cells from a human neural forebrain-derived stem cell line (hNS1) with rat striatal brain slices. In brief, coronal slices of neonatal rat striatum were cultured on semiporous membrane inserts placed in six-well trays overlying monolayers of hNS1 cells. After 12 days of co......Properly committed neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. To establish a setting for identification of secreted neural compounds promoting dopaminergic...

Dietary nucleotide supplementation raises erythrocyte 2, 3-diphosphoglycerate concentration in neonatal rats.

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Scopesi, F; Verkeste, C M; Paola, D; Gazzolo, D; Pronzato, M A; Bruschettini, P L; Marinari, U M

1999-03-01

The present study was designed to test if dietary intake of nucleotides increases erythrocyte 2,3-diphosphoglycerate (2,3-DPG) in neonatal rats. To this end, rat pups were fed a nucleotide-supplemented formula (S, n = 14) from d 9 until d 16 after birth. The results were compared with those obtained from a group of breast-fed pups (C, n = 14) and a group of pups artificially fed with nucleotide-free formula (NS, n = 14). Neonatal weight, 2,3-DPG concentration, hematocrit (Hct) and hemoglobin concentration (Hb) were determined before the experiment (d 9) and after 7 d of treatment (d 16). In all groups, 2,3-DPG concentration was greater at d 16 than d 9, and the increase was greater in the S group than in the NS group. Alterations in neonatal weight, Hct and Hb concentration did not differ among the groups. On d 16 the 2, 3-DPG/Hb ratio, reflecting the affinity of hemoglobin for oxygen, was significantly higher in the C and S groups than in the NS group. We conclude that in neonatal rats, dietary nucleotides increase erythrocyte 2,3-DPG concentration. Studies need to be conducted in humans to assess the effect of this increase on both neonatal peripheral hemodynamics and metabolism in this species.

Neonatal hypoglycemic brain injury is a cause of infantile spasms

OpenAIRE

YANG, GUANG; ZOU, LI-PING; WANG, JING; SHI, XIUYU; TIAN, SHUPING; YANG, XIAOFAN; JU, JUN; YAO, HONGXIANG; LIU, YUJIE

2016-01-01

Neonatal hypoglycemic brain injury is one of the causes of infantile spasms. In the present study, the clinical history and auxiliary examination results of 18 patients who developed infantile spasms several months after neonatal hypoglycemia were retrospectively analyzed. Among the 666 patients with infantile spasms admitted to two pediatric centers between January 2008 and October 2012, 18 patients developed infantile spasms after being diagnosed with neonatal hypoglycemia, defined as a who...

Long-term effects of enriched environment following neonatal hypoxia-ischemia on behavior, BDNF and synaptophysin levels in rat hippocampus: Effect of combined treatment with G-CSF.

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Griva, Myrsini; Lagoudaki, Rosa; Touloumi, Olga; Nousiopoulou, Evangelia; Karalis, Filippos; Georgiou, Thomas; Kokaraki, Georgia; Simeonidou, Constantina; Tata, Despina A; Spandou, Evangelia

2017-07-15

Increasing evidence shows that exposure to an enriched environment (EE) is neuroprotective in adult and neonatal animal models of brain ischemia. However, the mechanisms underlying this effect remain unclear. The aim of the current study was to investigate whether post-weaning EE would be effective in preventing functional deficits and brain damage by affecting markers of synaptic plasticity in a neonatal rat model of hypoxia-ischemia (HI). We also examined the possibility that granulocyte-colony stimulating factor (G-CSF), a growth factor with known neuroprotective effects in a variety of experimental brain injury models, combined with EE stimulation could enhance the potential beneficial effect of EE. Seven-day-old Wistar rats of either sex were subjected to permanent ligation of the left common carotid artery followed by 60min of hypoxia (8% O 2 ) and immediately after weaning (postnatal day 21) were housed in enriched conditions for 4weeks. A group of enriched-housed rats had been treated with G-CSF immediately after HI for 5 consecutive days (50μg/kg/day). Behavioral examination took place approximately at three months of age and included assessments of learning and memory (Morris water maze) as well as motor coordination (Rota-Rod). Infarct size and hippocampal area were estimated following behavioral assessment. Synaptic plasticity was evaluated based on BDNF and synaptophysin expression in the dorsal hippocampus. EE resulted in recovery of post-HI motor deficits and partial improvement of memory impairments which was not accompanied by reduced brain damage. Increased synaptophysin expression was observed in the contralateral to carotid ligation hemisphere. Hypoxia-ischemia alone or followed by enriched conditions did not affect BDNF expression which was increased only in enriched-housed normal rats. The combined therapy of G-CSF and EE further enhanced cognitive function compared to EE provided as monotherapy and prevented HI-induced brain damage by

Effect of manganese on neonatal rat: manganese concentration and enzymatic alterations in brain

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Seth, P K; Husain, R; Mushtaq, M; Chandra, S V

1977-01-01

Suckling rats were exposed for 15 and 30 days to manganese through the milk of nursing dams receiving 15 mg MnCl/sub 2/.4H/sub 2/O/kg/day orally and after which the neurological manifestations of metal poisoning were studied. No significant differences in the growth rate, developmental landmarks and walking movements were observed between the control and manganese-exposed pups. The metal concentration was significantly increased in the brain of manganese-fed pups at 15 days and exhibited a further three-fold increase over the control, at 30 days. The accumulation of the metal in the brain of manganese-exposed nursing dams was comparatively much less. A significant decrease in succinic dehydrogenase, adenosine triphosphatase, adenosine deaminase, acetylcholine esterase and an increase in monoamine oxidase activity was observed in the brain of experimental pups and dams. The results suggest that the developing brain may also be susceptible to manganese.

Alterations to prepulse inhibition magnitude and latency in adult rats following neonatal treatment with domoic acid and social isolation rearing.

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Marriott, Amber L; Tasker, R Andrew; Ryan, Catherine L; Doucette, Tracy A

2016-02-01

Deficits in perceptual, informational, and attentional processing are consistently identified as a core feature in schizophrenia and related neuropsychiatric disorders. Neonatal injections of low doses of the AMPA/kainate agonist domoic acid (DOM) have previously been shown to alter various aspects of perceptual and attentional processing in adult rats. The current study investigated the effects of combined neonatal DOM treatment with isolation rearing on prepulse inhibition behaviour and relevant neurochemical measures, to assess the usefulness of these paradigms in modeling neurodevelopmental disorders. Daily subcutaneous injections of DOM (20 μg/kg) or saline were administered to male and female rat pups from postnatal days (PND) 8-14. After weaning, rats were either housed alone or in groups of 4. Both the magnitude and latency of prepulse inhibition were determined in adulthood (approximately 4.5 months of age) and post-mortem brain tissue was assayed using Western blot. Social isolation alone significantly lowered PPI magnitude in male (but not female) rats while DOM treatment appeared to make animals refractory to this effect. Combining social isolation and DOM treatment caused an additive decrease in PPI startle latency. No statistically significant differences were found in the expression of D1, D2, TH, GAD65 or GAD67 protein in either the prefrontal cortex or hippocampus, although some tendencies toward differences were noted. We conclude that both neonatal low-dose DOM and social isolation affect prepulse inhibition in rats but that each paradigm exerts these effects through different neuronal signalling systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Simvastatin Attenuates Neurogenetic Damage and Improves Neurocongnitive Deficits Induced by Isoflurane in Neonatal Rats

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Ning Wang

2018-03-01

Full Text Available Background/Aims: Isoflurane inhibited neurogenesis and induced subsequent neurocognitive deficits in developing brain. Simvastatin exerts neuroprotection in a wide range of brain injury models. In the present study, we investigated whether simvastatin could attenuate neurogenetic inhibition and cognitive deficits induced by isoflurane exposure in neonatal rats. Methods: Sprague-Dawley rats at postnatal day (PND 7 and neural stem cells (NSCs were treated with either gas mixture, isoflurane, or simvastatin 60 min prior to isoflurane exposure, respectively. The rats were decapitated at PND 8 and PND 10 for detection of neurogenesis in the subventricular zone (SVZ and subgranular zone (SGZ of the hippocampus by immunostaining. NSC proliferation, viability and apoptosis were assessed by immunohistochemistry, CCK-8 and TUNEL, respectively. The protein expressions of caspase-3, p-Akt and p-GSK-3β both in vivo and vitro were assessed by western blotting. Cognitive functions were assessed by Morris Water Maze test and context fear conditioning test at the adult. Results: Isoflurane exposure inhibited neurogenesis in the SVZ and SGZ, decreased NSC proliferation and viability, promoted NSC apoptosis and led to late cognitive deficits. Furthermore, isoflurane increased caspase-3 expression and decreased protein expressions of p-Akt and p-GSK-3β both in vivo and in vitro. Pretreatment with simvastatin attenuated isoflurane-elicited changes in NSCs and cognitive function. Co-treatment with LY294002 reversed the effect of simvastatin on NSCs in vitro. Conclusion: We for the first time showed that simvastatin, by upregulating Akt/GSK-3β signaling pathway, alleviated isoflurane-induced neurogenetic damage and neurocognitive deficits in developing rat brain.

Neonatal exposure to phenobarbital potentiates schizophrenia-like behavioral outcomes in the rat.

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Bhardwaj, S K; Forcelli, P A; Palchik, G; Gale, K; Srivastava, L K; Kondratyev, A

2012-06-01

Previous work has indicated an association between seizures early in life and increased risk of psychiatric disorders, including schizophrenia. However, because early-life seizures are commonly treated with antiepileptic drugs (AEDs) such as phenobarbital, the possibility that drug treatment may affect later-life psychiatric outcomes needs to be evaluated. We therefore tested the hypothesis that phenobarbital exposure in the neonatal rat increases the risk of schizophrenia-like behavioral abnormalities in adulthood. Thus, in this study, we examined the effects of a single acute neonatal exposure to phenobarbital on adult behavioral outcomes in the rat neonatal ventral hippocampal (nVH) lesion model of schizophrenia. We compared these outcomes to those in rats a) without nVH lesions and b) with nVH lesions, without phenobarbital. The tasks used for behavioral evaluation were: amphetamine-induced locomotion, prepulse inhibition, elevated plus-maze, and novel object recognition task. We found that neonatal phenobarbital treatment (in the absence of nVH lesions) was sufficient to disrupt sensorimotor gating (as tested by prepulse inhibition) in adulthood to an extent equivalent to nVH lesions. Additionally, neonatal phenobarbital exposure enhanced the locomotor response to amphetamine in adult animals with and without nVH lesions. Our findings suggest that neonatal exposure to phenobarbital can predispose to schizophrenia-like behavioral abnormalities. Our findings underscore the importance of examining AED exposure early in life as a potential risk factor for later-life neuropsychiatric abnormalities in clinical populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Distribution Dynamics of Recombinant Lactobacillus in the Gastrointestinal Tract of Neonatal Rats

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Bao, Sujin; Zhu, Libin; Zhuang, Qiang; Wang, Lucia; Xu, Pin-Xian; Itoh, Keiji; Holzman, Ian R.; Lin, Jing

2013-01-01

One approach to deliver therapeutic agents, especially proteins, to the gastro-intestinal (GI) tract is to use commensal bacteria as a carrier. Genus Lactobacillus is an attractive candidate for use in this approach. However, a system for expressing exogenous proteins at a high level has been lacking in Lactobacillus. Moreover, it will be necessary to introduce the recombinant Lactobacillus into the GI tract, ideally by oral administration. Whether orally administered Lactobacillus can reach and reside in the GI tract has not been explored in neonates. In this study, we have examined these issues in neonatal rats. To achieve a high level of protein expression in Lactobacillus, we tested the impact of three promoters and two backbones on protein expression levels using mRFP1, a red fluorescent protein, as a reporter. We found that a combination of an L-lactate dehydrogenase (ldhL) promoter of Lactobacillus sakei with a backbone from pLEM415 yielded the highest level of reporter expression. When this construct was used to transform Lactobacillus casei, Lactobacillus delbrueckii and Lactobacillus acidophilus, high levels of mRFP1 were detected in all these species and colonies of transformed Lactobacillus appeared pink under visible light. To test whether orally administered Lactobacillus can be retained in the GI tract of neonates, we fed the recombinant Lactobacillus casei to neonatal rats. We found that about 3% of the bacteria were retained in the GI tract of the rats at 24 h after oral feeding with more recombinant Lactobacillus in the stomach and small intestine than in the cecum and colon. No mortality was observed throughout this study with Lactobacillus. In contrast, all neonatal rats died within 24 hours after fed with transformed E. coli. Taken together, our results indicate that Lactobacillus has the potential to be used as a vehicle for the delivery of therapeutic agents to neonates. PMID:23544119

Blood-brain barrier and cerebral blood flow: Age differences in hemorrhagic stroke

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Semyachkina-Glushkovskaya Oxana

2015-11-01

Full Text Available Neonatal stroke is similar to the stroke that occurs in adults and produces a significant morbidity and long-term neurologic and cognitive deficits. There are important differences in the factors, clinical events and outcomes associated with the stroke in infants and adults. However, mechanisms underlying age differences in the stroke development remain largely unknown. Therefore, treatment guidelines for neonatal stroke must extrapolate from the adult data that is often not suitable for children. The new information about differences between neonatal and adult stroke is essential for identification of significant areas for future treatment and effective prevention of neonatal stroke. Here, we studied the development of stress-induced hemorrhagic stroke and possible mechanisms underlying these processes in newborn and adult rats. Using histological methods and magnetic resonance imaging, we found age differences in the type of intracranial hemorrhages. Newborn rats demonstrated small superficial bleedings in the cortex while adult rats had more severe deep bleedings in the cerebellum. Using Doppler optical coherent tomography, we found higher stress-reactivity of the sagittal sinus to deleterious effects of stress in newborn vs. adult rats suggesting that the cerebral veins are more vulnerable to negative stress factors in neonatal vs. adult brain in rats. However, adult but not newborn rats demonstrated the stroke-induced breakdown of blood brain barrier (BBB permeability. The one of possible mechanisms underlying the higher resistance to stress-related stroke injures of cerebral vessels in newborn rats compared with adult animals is the greater expression of two main tight junction proteins of BBB (occludin and claudin-5 in neonatal vs. mature brain in rats.

Enhancement of intestinal growth in neonatal rats by epidermal growth factor in milk

International Nuclear Information System (INIS)

Berseth, C.L.

1987-01-01

Breast milk has been shown to enhance neonatal intestinal growth. Because epidermal growth factor (EGF) is present in the milk of various mammalian species, the hypothesis was tested that EGF in rodent milk mediates, in part, the breast milk-enhanced intestinal growth in neonatal rat. Fifty-eight rat pups fed artificial formal that contained 1.2, 3.0, and 6.0 μg/ml EGF for 39 h had greater incorporation of [ 3 H]thymidine into DNA and DNA content of intestine than 29 pups fed unsupplemented formula. Pups fed EGF for 5 days had significantly greater body weight, intestinal weight, length, and DNA content than control pups. Conversely, pups fed pooled rat milk containing rabbit-derived antibody to EGF for 39 h had intestines of lower weight that contained less DNA than animals fed rat milk containing normal rabbit serum. EGF appears to mediate, in part, breast milk-enhanced neonatal intestinal growth

Magnetic resonance imaging based noninvasive measurements of brain hemodynamics in neonates

DEFF Research Database (Denmark)

De Vis, Jill B; Alderliesten, Thomas; Hendrikse, Jeroen

2016-01-01

Perinatal disturbances of brain hemodynamics can have a detrimental effect on the brain's parenchyma with consequently adverse neurodevelopmental outcome. Noninvasive, reliable tools to evaluate the neonate's brain hemodynamics are scarce. Advances in magnetic resonance imaging have provided new...

Edaravone attenuates neuronal apoptosis in hypoxic-ischemic brain damage rat model via suppression of TRAIL signaling pathway.

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Li, Chunyi; Mo, Zhihuai; Lei, Junjie; Li, Huiqing; Fu, Ruying; Huang, Yanxia; Luo, Shijian; Zhang, Lei

2018-06-01

Edaravone is a new type of oxygen free radical scavenger and able to attenuate various brain damage including hypoxic-ischemic brain damage (HIBD). This study was aimed at investigating the neuroprotective mechanism of edaravone in rat hypoxic-ischemic brain damage model and its correlation with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling pathway. 75 seven-day-old Sprague-Dawley neonatal rats were equally divided into three groups: sham-operated group (sham), HIBD group and HIBD rats injected with edaravone (HIBD + EDA) group. Neurological severity and space cognitive ability of rats in each group were evaluated using Longa neurological severity score and Morris water maze testing. TUNEL assay and flow cytometry were used to determine brain cell apoptosis. Western blot was used to estimate the expression level of death receptor-5 (DR5), Fas-associated protein with death domain (FADD), caspase 8, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax). In addition, immunofluorescence was performed to detect caspase 3. Edaravone reduced neurofunctional damage caused by HIBD and improved the cognitive capability of rats. The above experiment results suggested that edaravone could down-regulate the expression of active caspase 3 protein, thereby relieving neuronal apoptosis. Taken together, edaravone could attenuate neuronal apoptosis in rat hypoxic-ischemic brain damage model via suppression of TRAIL signaling pathway, which also suggested that edaravone might be an effective therapeutic strategy for HIBD clinical treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Brain Metabolism Alterations Induced by Pregnancy Swimming Decreases Neurological Impairments Following Neonatal Hypoxia-Ischemia in Very Immature Rats

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Eduardo F. Sanches

2018-06-01

Full Text Available Introduction: Prematurity, through brain injury and altered development is a major cause of neurological impairments and can result in motor, cognitive and behavioral deficits later in life. Presently, there are no well-established effective therapies for preterm brain injury and the search for new strategies is needed. Intra-uterine environment plays a decisive role in brain maturation and interventions using the gestational window have been shown to influence long-term health in the offspring. In this study, we investigated whether pregnancy swimming can prevent the neurochemical metabolic alterations and damage that result from postnatal hypoxic-ischemic brain injury (HI in very immature rats.Methods: Female pregnant Wistar rats were divided into swimming (SW or sedentary (SE groups. Following a period of adaptation before mating, swimming was performed during the entire gestation. At postnatal day (PND3, rat pups from SW and SE dams had right common carotid artery occluded, followed by systemic hypoxia. At PND4 (24 h after HI, the early neurochemical profile was measured by 1H-magnetic resonance spectroscopy. Astrogliosis, apoptosis and neurotrophins protein expression were assessed in the cortex and hippocampus. From PND45, behavioral testing was performed. Diffusion tensor imaging and neurite orientation dispersion and density imaging were used to evaluate brain microstructure and the levels of proteins were quantified.Results: Pregnancy swimming was able to prevent early metabolic changes induced by HI preserving the energetic balance, decreasing apoptotic cell death and astrogliosis as well as maintaining the levels of neurotrophins. At adult age, swimming preserved brain microstructure and improved the performance in the behavioral tests.Conclusion: Our study points out that swimming during gestation in rats could prevent prematurity related brain damage in progeny with high translational potential and possibly interesting cost

Statistical language learning in neonates revealed by event-related brain potentials

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Näätänen Risto

2009-03-01

Full Text Available Abstract Background Statistical learning is a candidate for one of the basic prerequisites underlying the expeditious acquisition of spoken language. Infants from 8 months of age exhibit this form of learning to segment fluent speech into distinct words. To test the statistical learning skills at birth, we recorded event-related brain responses of sleeping neonates while they were listening to a stream of syllables containing statistical cues to word boundaries. Results We found evidence that sleeping neonates are able to automatically extract statistical properties of the speech input and thus detect the word boundaries in a continuous stream of syllables containing no morphological cues. Syllable-specific event-related brain responses found in two separate studies demonstrated that the neonatal brain treated the syllables differently according to their position within pseudowords. Conclusion These results demonstrate that neonates can efficiently learn transitional probabilities or frequencies of co-occurrence between different syllables, enabling them to detect word boundaries and in this way isolate single words out of fluent natural speech. The ability to adopt statistical structures from speech may play a fundamental role as one of the earliest prerequisites of language acquisition.

[Effect of leptin on long-term spatial memory of rats with white matter damage in developing brain].

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Feng, Er-Cui; Jiang, Li

2017-12-01

To investigate the neuroprotective effect of leptin by observing its effect on spatial memory of rats with white matter damage in developing brain. A total of 80 neonatal rats were randomly divided into 3 groups: sham-operation (n=27), model (n=27) and leptin intervention (n=27). The rats in the model and leptin intervention groups were used to prepare a model of white matter damage in developing brain, and the rats in the leptin intervention group were given leptin (100 μg/kg) diluted with normal saline immediately after modelling for 4 consecutive days. The survival rate of the rats was observed and the change in body weight was monitored. When the rats reached the age of 21 days, the Morris water maze test was used to evaluate spatial memory. There was no significant difference in the survival rate of rats between the three groups (P>0.05). Within 10 days after birth, the leptin intervention group had similar body weight as the sham-operation group and significantly lower body weight than the model group (P0.05). The results of place navigation showed that from the second day of experiment, there was a significant difference in the latency period between the three groups (Pmemory impairment of rats with white matter damage in developing brain. It thus exerts a neuroprotective effect, and is worthy of further research.

Involvement of neuronal IL-1β in acquired brain lesions in a rat model of neonatal encephalopathy.

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Savard, Alexandre; Lavoie, Karine; Brochu, Marie-Elsa; Grbic, Djordje; Lepage, Martin; Gris, Denis; Sebire, Guillaume

2013-09-05

Infection-inflammation combined with hypoxia-ischemia (HI) is the most prevalent pathological scenario involved in perinatal brain damage leading to life-long neurological disabilities. Following lipopolysaccharide (LPS) and/or HI aggression, different patterns of inflammatory responses have been uncovered according to the brain differentiation stage. In fact, LPS pre-exposure has been reported to aggravate HI brain lesions in post-natal day 1 (P1) and P7 rat models that are respectively equivalent - in terms of brain development - to early and late human preterm newborns. However, little is known about the innate immune response in LPS plus HI-induced lesions of the full-term newborn forebrain and the associated neuropathological and neurobehavioral outcomes. An original preclinical rat model has been previously documented for the innate neuroimmune response at different post-natal ages. It was used in the present study to investigate the neuroinflammatory mechanisms that underline neurological impairments after pathogen-induced inflammation and HI in term newborns. LPS and HI exerted a synergistic detrimental effect on rat brain. Their effect led to a peculiar pattern of parasagittal cortical-subcortical infarcts mimicking those in the human full-term newborn with subsequent severe neurodevelopmental impairments. An increased IL-1β response in neocortical and basal gray neurons was demonstrated at 4 h after LPS + HI-exposure and preceded other neuroinflammatory responses such as microglial and astroglial cell activation. Neurological deficits were observed during the acute phase of injury followed by a recovery, then by a delayed onset of profound motor behavior impairment, reminiscent of the delayed clinical onset of motor system impairments observed in humans. Interleukin-1 receptor antagonist (IL-1ra) reduced the extent of brain lesions confirming the involvement of IL-1β response in their pathophysiology. In rat pups at a neurodevelopmental age

Inflammation, caffeine and adenosine in neonatal hypoxic ischemic brain injury

OpenAIRE

Winerdal, Max

2014-01-01

Background: Brain injury during the neonatal period has potentially lifelong consequences for a child. Perinatal infections and inflammation can induce preterm birth and unfavorable cognitive development, Thus inflammation has received enthusiastic interest for potential therapeutic approaches seeking to protect the newborn brain. Experimental evidence demonstrates that inflammation induces brain injury succeeding the initial insult. A key cytokine in brain injury is the tumor necrosis factor...

Plasticity in the Neonatal Brain following Hypoxic-Ischaemic Injury

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Eridan Rocha-Ferreira

2016-01-01

Full Text Available Hypoxic-ischaemic damage to the developing brain is a leading cause of child death, with high mortality and morbidity, including cerebral palsy, epilepsy, and cognitive disabilities. The developmental stage of the brain and the severity of the insult influence the selective regional vulnerability and the subsequent clinical manifestations. The increased susceptibility to hypoxia-ischaemia (HI of periventricular white matter in preterm infants predisposes the immature brain to motor, cognitive, and sensory deficits, with cognitive impairment associated with earlier gestational age. In term infants HI causes selective damage to sensorimotor cortex, basal ganglia, thalamus, and brain stem. Even though the immature brain is more malleable to external stimuli compared to the adult one, a hypoxic-ischaemic event to the neonate interrupts the shaping of central motor pathways and can affect normal developmental plasticity through altering neurotransmission, changes in cellular signalling, neural connectivity and function, wrong targeted innervation, and interruption of developmental apoptosis. Models of neonatal HI demonstrate three morphologically different types of cell death, that is, apoptosis, necrosis, and autophagy, which crosstalk and can exist as a continuum in the same cell. In the present review we discuss the mechanisms of HI injury to the immature brain and the way they affect plasticity.

Neonatal bee venom exposure induces sensory modality-specific enhancement of nociceptive response in adult rats.

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Li, Mengmeng; Chen, Huisheng; Tang, Jiaguang; Chen, Jun

2014-06-01

Previous studies have shown that inflammatory pain at the neonatal stage can produce long-term structural and functional changes in nociceptive pathways, resulting in altered pain perception in adulthood. However, the exact pattern of altered nociceptive response and associated neurochemical changes in the spinal cord in this process is unclear. In this study, we used an experimental paradigm in which each rat first received intraplantar bee venom (BV) or saline injection on postnatal day 1, 4, 7, 14, 21, or 28. This was followed 2 months later by a second intraplantar bee venom injection in the same rats to examine the difference in nociceptive responses. We found that neonatal inflammatory pain induced by the first BV injection significantly reduced baseline paw withdrawal mechanical threshold, but not baseline paw withdrawal thermal latency, when rats were examined 2 months from the first BV injection. Neonatal inflammatory pain also exacerbated mechanical, but not thermal, hyperalgesia in response to the second BV injection in these same rats. Rats exposed to neonatal inflammation also showed up-regulation of spinal NGF, TrkA receptor, BDNF, TrkB receptor, IL-1β, and COX-2 expression following the second BV injection, especially with prior BV exposure on postnatal day 21 or 28. These results indicate that neonatal inflammation produces sensory modality-specific changes in nociceptive behavior and alters neurochemistry in the spinal cord of adult rats. These results also suggest that a prior history of inflammatory pain during the developmental period might have an impact on clinical pain in highly susceptible adult patients. Wiley Periodicals, Inc.

Fetal trauma: brain imaging in four neonates

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Breysem, Luc; Mussen, E.; Demaerel, P.; Smet, M. [Department of Radiology, University Hospitals, Herestraat 49, 3000, Leuven (Belgium); Cossey, V. [Department of Pediatrics, University Hospitals, Leuven (Belgium); Voorde, W. van de [Department of Forensic Medicine, University Hospitals, Leuven (Belgium)

2004-09-01

The purpose of this paper is to describe brain pathology in neonates after major traffic trauma in utero during the third trimester. Our patient cohort consisted of four neonates born by emergency cesarean section after car accident in the third trimester of pregnancy. The median gestational age (n=4) was 36 weeks (range: 30-38). Immediate post-natal and follow-up brain imaging consisted of cranial ultrasound (n=4), computed tomography (CT) (n=1) and post-mortem magnetic resonance imaging (MRI) (n=1). Pathology findings were correlated with the imaging findings (n=3). Cranial ultrasound demonstrated a huge subarachnoidal hemorrhage (n=1), subdural hematoma (n=1), brain edema with inversion of the diastolic flow (n=1) and severe ischemic changes (n=1). In one case, CT demonstrated the presence and extension of the subarachnoidal hemorrhage, a parietal fracture and a limited intraventricular hemorrhage. Cerebellar hemorrhage and a small cerebral frontal contusion were seen on post-mortem MRI in a child with a major subarachnoidal hemorrhage on ultrasound. None of these four children survived (three children died within 2 days and one child died after 1 month). Blunt abdominal trauma during pregnancy can cause fetal cranial injury. In our cases, skull fracture, intracranial hemorrhage and hypoxic-ischemic encephalopathy were encountered. (orig.)

Fetal trauma: brain imaging in four neonates

International Nuclear Information System (INIS)

Breysem, Luc; Mussen, E.; Demaerel, P.; Smet, M.; Cossey, V.; Voorde, W. van de

2004-01-01

The purpose of this paper is to describe brain pathology in neonates after major traffic trauma in utero during the third trimester. Our patient cohort consisted of four neonates born by emergency cesarean section after car accident in the third trimester of pregnancy. The median gestational age (n=4) was 36 weeks (range: 30-38). Immediate post-natal and follow-up brain imaging consisted of cranial ultrasound (n=4), computed tomography (CT) (n=1) and post-mortem magnetic resonance imaging (MRI) (n=1). Pathology findings were correlated with the imaging findings (n=3). Cranial ultrasound demonstrated a huge subarachnoidal hemorrhage (n=1), subdural hematoma (n=1), brain edema with inversion of the diastolic flow (n=1) and severe ischemic changes (n=1). In one case, CT demonstrated the presence and extension of the subarachnoidal hemorrhage, a parietal fracture and a limited intraventricular hemorrhage. Cerebellar hemorrhage and a small cerebral frontal contusion were seen on post-mortem MRI in a child with a major subarachnoidal hemorrhage on ultrasound. None of these four children survived (three children died within 2 days and one child died after 1 month). Blunt abdominal trauma during pregnancy can cause fetal cranial injury. In our cases, skull fracture, intracranial hemorrhage and hypoxic-ischemic encephalopathy were encountered. (orig.)

Diffusion MRI of the neonate brain: acquisition, processing and analysis techniques

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Pannek, Kerstin [University of Queensland, Centre for Clinical Research, Brisbane (Australia); University of Queensland, School of Medicine, Brisbane (Australia); University of Queensland, Centre for Advanced Imaging, Brisbane (Australia); Guzzetta, Andrea [IRCCS Stella Maris, Department of Developmental Neuroscience, Calambrone Pisa (Italy); Colditz, Paul B. [University of Queensland, Centre for Clinical Research, Brisbane (Australia); University of Queensland, Perinatal Research Centre, Brisbane (Australia); Rose, Stephen E. [University of Queensland, Centre for Clinical Research, Brisbane (Australia); University of Queensland, Centre for Advanced Imaging, Brisbane (Australia); University of Queensland Centre for Clinical Research, Royal Brisbane and Women' s Hospital, Brisbane (Australia)

2012-10-15

Diffusion MRI (dMRI) is a popular noninvasive imaging modality for the investigation of the neonate brain. It enables the assessment of white matter integrity, and is particularly suited for studying white matter maturation in the preterm and term neonate brain. Diffusion tractography allows the delineation of white matter pathways and assessment of connectivity in vivo. In this review, we address the challenges of performing and analysing neonate dMRI. Of particular importance in dMRI analysis is adequate data preprocessing to reduce image distortions inherent to the acquisition technique, as well as artefacts caused by head movement. We present a summary of techniques that should be used in the preprocessing of neonate dMRI data, and demonstrate the effect of these important correction steps. Furthermore, we give an overview of available analysis techniques, ranging from voxel-based analysis of anisotropy metrics including tract-based spatial statistics (TBSS) to recently developed methods of statistical analysis addressing issues of resolving complex white matter architecture. We highlight the importance of resolving crossing fibres for tractography and outline several tractography-based techniques, including connectivity-based segmentation, the connectome and tractography mapping. These techniques provide powerful tools for the investigation of brain development and maturation. (orig.)

Effect of neonatal nociceptin or nocistatin imprinting on the brain concentration of biogenic amines and their metabolites.

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Tekes, Kornélia; Gyenge, Melinda; Sótonyi, Péter; Csaba, György

2009-04-01

Noradrenaline (NA), dopamine (DA), homovanillic acid (HA), serotonin (5HT) and 5-hydroxyindole acetic acid (5HIAA) content of five brain regions (hypothalamus, hippocampus, brainstem, striatum and frontal cortex) and the cerebrospinal fluid (CSF) was measured in adult (three months old) male and female rats treated neonatally with a single dose of 10 microg nociceptin (NC) or 10 microg nocistatin (NS) for hormonal imprinting. The biogenic amine and metabolite content of cerebrospinal fluid was also determined. In NC treated animals the serotonergic, dopaminergic as well as noradrenergic systems were influenced by the imprinting. The 5HT level increased in hypothalamus, the 5HIAA tissue levels were found increased in hypothalamus. Hippocampus and striatum and the HVA levels increased highly significantly in brainstem. Dopamine level decreased significantly in striatum, however in frontal cortex both noradrenalin and 5HIAA level decreased. Nevertheless, in NS-treated rats decreased NA tissue levels were found in hypothalamus, brainstem and frontal cortex. Decreased DA levels were found in the hypothalamus, brainstem and striatum. NS imprinting resulted in decreased HVA level, but increased one in the brainstem. The 5HT levels decreased in the hypothalamus, brainstem, striatum and frontal cortex, while 5HIAA content of CSF, and frontal cortex decreased, and that of hypothalamus, hippocampus and striatum increased. There was no significant difference between genders except in the 5HT tissue levels of NC treated rats. Data presented show that neonatal imprinting both by NC and NS have long-lasting and brain area specific effects. In earlier experiments endorphin imprinting also influenced the serotonergic system suggesting that during labour release of pain-related substances may durably affect the serotonergic (dopaminergic, adrenergic) system which can impress the animals' later behavior.

An improved in vitro blood-brain barrier model: rat brain endothelial cells co-cultured with astrocytes.

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Abbott, N Joan; Dolman, Diana E M; Drndarski, Svetlana; Fredriksson, Sarah M

2012-01-01

In vitro blood-brain barrier (BBB) models using primary cultured brain endothelial cells are important for establishing cellular and molecular mechanisms of BBB function. Co-culturing with BBB-associated cells especially astrocytes to mimic more closely the in vivo condition leads to upregulation of the BBB phenotype in the brain endothelial cells. Rat brain endothelial cells (RBECs) are a valuable tool allowing ready comparison with in vivo studies in rodents; however, it has been difficult to obtain pure brain endothelial cells, and few models achieve a transendothelial electrical resistance (TEER, measure of tight junction efficacy) of >200 Ω cm(2), i.e. the models are still relatively leaky. Here, we describe methods for preparing high purity RBECs and neonatal rat astrocytes, and a co-culture method that generates a robust, stable BBB model that can achieve TEER >600 Ω cm(2). The method is based on >20 years experience with RBEC culture, together with recent improvements to kill contaminating cells and encourage BBB differentiation.Astrocytes are isolated by mechanical dissection and cell straining and are frozen for later co-culture. RBECs are isolated from 3-month-old rat cortices. The brains are cleaned of meninges and white matter and enzymatically and mechanically dissociated. Thereafter, the tissue homogenate is centrifuged in bovine serum albumin to separate vessel fragments from other cells that stick to the myelin plug. The vessel fragments undergo a second enzyme digestion to separate pericytes from vessels and break down vessels into shorter segments, after which a Percoll gradient is used to separate capillaries from venules, arterioles, and single cells. To kill remaining contaminating cells such as pericytes, the capillary fragments are plated in puromycin-containing medium and RBECs grown to 50-60% confluence. They are then passaged onto filters for co-culture with astrocytes grown in the bottom of the wells. The whole procedure takes ∼2

Functional photoacoustic tomography for neonatal brain imaging: developments and challenges

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Hariri, Ali; Tavakoli, Emytis; Adabi, Saba; Gelovani, Juri; Avanaki, Mohammad R. N.

2017-03-01

Transfontanelle ultrasound imaging (TFUSI) is a routine diagnostic brain imaging method in infants who are born prematurely, whose skull bones have not completely fused together and have openings between them, so-called fontanelles. Open fontanelles in neonates provide acoustic windows, allowing the ultrasound beam to freely pass through. TFUSI is used to rule out neurological complications of premature birth including subarachnoid hemorrhage (SAH), intraventricular (IVH), subependimal (SEPH), subdural (SDH) or intracerebral (ICH) hemorrhages, as well as hypoxic brain injuries. TFUSI is widely used in the clinic owing to its low cost, safety, accessibility, and noninvasive nature. Nevertheless, the accuracy of TFUSI is limited. To address several limitations of current clinical imaging modalities, we develop a novel transfontanelle photoacoustic imaging (TFPAI) probe, which, for the first time, should allow for non-invasive structural and functional imaging of the infant brain. In this study, we test the feasibility of TFPAI for detection of experimentally-induced intra ventricular and Intraparenchymal hemorrhage phantoms in a sheep model with a surgically-induced cranial window which will serve as a model of neonatal fontanelle. This study is towards using the probe we develop for bedside monitoring of neonates with various disease conditions and complications affecting brain perfusion and oxygenation, including apnea, asphyxia, as well as for detection of various types of intracranial hemorrhages (SAH, IVH, SEPH, SDH, ICH).

Characterization of nociceptive response to chemical, mechanical, and thermal stimuli in adolescent rats with neonatal dopamine depletion.

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Ogata, M; Noda, K; Akita, H; Ishibashi, H

2015-03-19

Rats with dopamine depletion caused by 6-hydroxydopamine (6-OHDA) treatment during adulthood and the neonatal period exhibit akinetic motor activity and spontaneous motor hyperactivity during adolescence, respectively, indicating that the behavioral effects of dopamine depletion depend on the period of lesion development. Dopamine depletion during adulthood induces hyperalgesic response to mechanical, thermal, and/or chemical stimuli, whereas the effects of neonatal dopamine depletion on nociceptive response in adolescent rats are yet to be examined. The latter aspect was addressed in this study, and behavioral responses were examined using von-Frey, tail flick, and formalin tests. The formalin test revealed that rats with neonatal dopamine depletion exhibited a significant increase in nociceptive response during interphase (6-15min post formalin injection) and phase 2 (16-75min post formalin injection). This increase in nociceptive response to the formalin injection was not reversed by pretreatment with methamphetamine, which ameliorates motor hyperactivity observed in adolescent rats with neonatal 6-OHDA treatment. The von-Frey filament and tail flick tests failed to reveal significant differences in withdrawal thresholds between neonatal 6-OHDA-treated and vehicle-treated rats. The spinal neuronal response to the formalin injection into the rat hind paw was also examined through immunohistochemical analysis of c-Fos protein. Significantly increased numbers of c-Fos-immunoreactive cells were observed in laminae I-II and V-VI of the ipsilateral spinal cord to the site of the formalin injection in rats with neonatal dopamine depletion compared with vehicle-treated rats. These results suggest that the dopaminergic neural system plays a crucial role in the development of a neural network for tonic pain, including the spinal neural circuit for nociceptive transmission, and that the mechanism underlying hyperalgesia to tonic pain is not always consistent with that of

Neonatal rat hearts cannot be protected by ischemic postconditioning

Czech Academy of Sciences Publication Activity Database

Doul, J.; Charvátová, Z.; Ošťádalová, Ivana; Kohutiar, M.; Maxová, H.; Ošťádal, Bohuslav

2015-01-01

Roč. 64, č. 6 (2015), s. 789-794 ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : neonatal rats * ischemic postconditioning * tolerance to ischemia * contractile function * lactate dehydrogenase Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.643, year: 2015

Differential expression of parvalbumin interneurons in neonatal phencyclidine treated rats and socially isolated rats

DEFF Research Database (Denmark)

Kaalund, Sanne Simone; Riise, Jesper; Broberg, Brian

2013-01-01

of parvalbumin-positive interneurons (PV(+) interneurons). In this study we examined PV(+) expression in two rat models of cognitive dysfunction in schizophrenia, the environmental social isolation (SI) and pharmacological neonatal phencyclidine (neoPCP) models. Using a stereological method, the optical...

Patterns of damage in the mature neonatal brain

International Nuclear Information System (INIS)

Triulzi, Fabio; Parazzini, Cecilia; Righini, Andrea

2006-01-01

Patterns of damage in the mature neonatal brain can be subdivided into focal, multifocal and diffuse. The main cause of diffuse brain damage in the term newborn is hypoxic-ischaemic encephalopathy (HIE). HIE is still the major recognized perinatal cause of neurological morbidity in full-term newborns. MRI offers today the highest sensitivity in detecting acute anoxic injury of the neonatal brain. Conventional acquisition techniques together with modern diffusion techniques can identify typical patterns of HIE injury, even in the early course of the disease. However, even though highly suggestive, these patterns cannot be considered as pathognomonic. Perinatal metabolic disease such as kernicterus and severe hypoglycaemia should be differentiated from classic HIE. Other conditions, such as infections, non-accidental injury and rarer metabolic diseases can be misinterpreted as HIE in their early course when diffuse brain swelling is still the predominant MRI feature. Diffusion techniques can help to differentiate different types of diffuse brain oedema. Typical examples of focal injuries are arterial or venous infarctions. In arterial infarction, diffusion techniques can define more precisely than conventional imaging the extent of focal infarction, even in the hyperacute phase. Moreover, diffusion techniques provide quantitative data of acute corticospinal tract injury, especially at the level of the cerebral peduncles. Venous infarction should be suspected in every case of unexplained cerebral haematoma in the full-term newborn. In the presence of spontaneous bleeding, venous structures should always be evaluated by MR angiography. (orig.)

Patterns of damage in the mature neonatal brain

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Triulzi, Fabio; Parazzini, Cecilia; Righini, Andrea [Children' s Hospital ' ' Vittore Buzzi' ' , Departments of Radiology and Neuroradiology, Milan (Italy)

2006-07-15

Patterns of damage in the mature neonatal brain can be subdivided into focal, multifocal and diffuse. The main cause of diffuse brain damage in the term newborn is hypoxic-ischaemic encephalopathy (HIE). HIE is still the major recognized perinatal cause of neurological morbidity in full-term newborns. MRI offers today the highest sensitivity in detecting acute anoxic injury of the neonatal brain. Conventional acquisition techniques together with modern diffusion techniques can identify typical patterns of HIE injury, even in the early course of the disease. However, even though highly suggestive, these patterns cannot be considered as pathognomonic. Perinatal metabolic disease such as kernicterus and severe hypoglycaemia should be differentiated from classic HIE. Other conditions, such as infections, non-accidental injury and rarer metabolic diseases can be misinterpreted as HIE in their early course when diffuse brain swelling is still the predominant MRI feature. Diffusion techniques can help to differentiate different types of diffuse brain oedema. Typical examples of focal injuries are arterial or venous infarctions. In arterial infarction, diffusion techniques can define more precisely than conventional imaging the extent of focal infarction, even in the hyperacute phase. Moreover, diffusion techniques provide quantitative data of acute corticospinal tract injury, especially at the level of the cerebral peduncles. Venous infarction should be suspected in every case of unexplained cerebral haematoma in the full-term newborn. In the presence of spontaneous bleeding, venous structures should always be evaluated by MR angiography. (orig.)

Synchronization of motor neurons during locomotion in the neonatal rat

DEFF Research Database (Denmark)

Tresch, Matthew C.; Kiehn, Ole

2002-01-01

We describe here the robust synchronization of motor neurons at a millisecond time scale during locomotor activity in the neonatal rat. Action potential activity of motor neuron pairs was recorded extracellularly using tetrodes during locomotor activity in the in vitro neonatal rat spinal cord....... Approximately 40% of motor neuron pairs recorded in the same spinal segment showed significant synchronization, with the duration of the central peak in cross-correlograms between motor neurons typically ranging between ∼ 30 and 100 msec. The percentage of synchronized motor neuron pairs was considerably higher...... between motor neurons persisted. On the other hand, both local and distant coupling between motor neurons were preserved after antagonism of gap junction coupling between motor neurons. These results demonstrate that motor neuron activity is strongly synchronized at a millisecond time scale during...

Hypothermia Modulates Cytokine Responses After Neonatal Rat Hypoxic-Ischemic Injury and Reduces Brain Damage

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Xiangpeng Yuan

2014-11-01

Full Text Available While hypothermia (HT is the standard-of-care for neonates with hypoxic ischemic injury (HII, the mechanisms underlying its neuroprotective effect are poorly understood. We examined ischemic core/penumbra and cytokine/chemokine evolution in a 10-day-old rat pup model of HII. Pups were treated for 24 hr after HII with HT (32℃; n = 18 or normothermia (NT, 35℃; n = 15. Outcomes included magnetic resonance imaging (MRI, neurobehavioral testing, and brain cytokine/chemokine profiling (0, 24, 48, and 72 hr post-HII. Lesion volumes (24 hr were reduced in HT pups (total 74%, p < .05; penumbra 68%, p < .05; core 85%, p = .19. Lesion volumes rebounded at 72 hr (48 hr post-HT with no significant differences between NT and HT pups. HT reduced interleukin-1β (IL-1β at all time points (p < .05; monocyte chemoattractant protein-1 (MCP-1 trended toward being decreased in HT pups (p = .09. The stem cell signaling molecule, stromal cell-derived factor-1 (SDF-1 was not altered by HT. Our data demonstrate that HT reduces total and penumbral lesion volumes (at 24 and 48 hr, potentially by decreasing IL-1β without affecting SDF-1. Disassociation between the increasing trend in HII volumes from 48 to 72 hr post-HII when IL-1β levels remained low suggests that after rewarming, mechanisms unrelated to IL-1β expression are likely to contribute to this delayed increase in injury. Additional studies should be considered to determine what these mechanisms might be and also to explore whether extending the duration or degree of HT might ameliorate this delayed increase in injury.

Altered resting-state whole-brain functional networks of neonates with intrauterine growth restriction.

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Batalle, Dafnis; Muñoz-Moreno, Emma; Tornador, Cristian; Bargallo, Nuria; Deco, Gustavo; Eixarch, Elisenda; Gratacos, Eduard

2016-04-01

The feasibility to use functional MRI (fMRI) during natural sleep to assess low-frequency basal brain activity fluctuations in human neonates has been demonstrated, although its potential to characterise pathologies of prenatal origin has not yet been exploited. In the present study, we used intrauterine growth restriction (IUGR) as a model of altered neurodevelopment due to prenatal condition to show the suitability of brain networks to characterise functional brain organisation at neonatal age. Particularly, we analysed resting-state fMRI signal of 20 neonates with IUGR and 13 controls, obtaining whole-brain functional networks based on correlations of blood oxygen level-dependent (BOLD) signal in 90 grey matter regions of an anatomical atlas (AAL). Characterisation of the networks obtained with graph theoretical features showed increased network infrastructure and raw efficiencies but reduced efficiency after normalisation, demonstrating hyper-connected but sub-optimally organised IUGR functional brain networks. Significant association of network features with neurobehavioral scores was also found. Further assessment of spatiotemporal dynamics displayed alterations into features associated to frontal, cingulate and lingual cortices. These findings show the capacity of functional brain networks to characterise brain reorganisation from an early age, and their potential to develop biomarkers of altered neurodevelopment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Connectivity of Pacemaker Neurons in the Neonatal Rat Superficial Dorsal Horn

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Ford, Neil C.; Arbabi, Shahriar; Baccei, Mark L.

2014-01-01

Pacemaker neurons with an intrinsic ability to generate rhythmic burst-firing have been characterized in lamina I of the neonatal spinal cord, where they are innervated by high-threshold sensory afferents. However, little is known about the output of these pacemakers, as the neuronal populations which are targeted by pacemaker axons have yet to be identified. The present study combines patch clamp recordings in the intact neonatal rat spinal cord with tract-tracing to demonstrate that lamina I pacemaker neurons contact multiple spinal motor pathways during early life. Retrograde labeling of premotor interneurons with the trans-synaptic virus PRV-152 revealed the presence of burst-firing in PRV-infected lamina I neurons, thereby confirming that pacemakers are synaptically coupled to motor networks in the spinal ventral horn. Notably, two classes of pacemakers could be distinguished in lamina I based on cell size and the pattern of their axonal projections. While small pacemaker neurons possessed ramified axons which contacted ipsilateral motor circuits, large pacemaker neurons had unbranched axons which crossed the midline and ascended rostrally in the contralateral white matter. Recordings from identified spino-parabrachial and spino-PAG neurons indicated the presence of pacemaker activity within neonatal lamina I projection neurons. Overall, these results show that lamina I pacemakers are positioned to regulate both the level of activity in developing motor circuits as well as the ascending flow of nociceptive information to the brain, thus highlighting a potential role for pacemaker activity in the maturation of pain and sensorimotor networks in the CNS. PMID:25380417

Hydrogen sulfide protects neonatal rat medulla oblongata against prenatal cigarette smoke exposure via anti-oxidative and anti-inflammatory effects.

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Yan, Xiang; Lei, Fang; Hu, Yajie; Nie, Lihong; Jia, Qingyi; Zhou, Hua; Zhao, Fusheng; Zheng, Yu

2018-01-01

We previously demonstrated that hydrogen sulfide (H 2 S) protected neonatal rat medulla oblongata from prenatal cigarette smoke exposure (CSE) via anti-apoptotic effect. The present work further investigated the involvement of anti-oxidative and anti-inflammatory effects of H 2 S in the protection. Pregnant Sprague-Dawley rats were randomly divided into NaCl, CSE, CSE + NaHS (a donor of H 2 S) and NaHS groups. All the tests were performed with corresponding neonatal rats. Nissl staining revealed that NaHS treatment ameliorated neuronal chromatolysis in the hypoglossal nucleus and nucleus ambiguus resulted from prenatal CSE. Moreover, NaHS eliminated decrease of glutathione level, increase of malondialdehyde content and inhibition of superoxide dismutase activity within neonatal rat medulla oblongata caused by prenatal CSE. NaHS also relieved the up-regulation of tumor necrosis factor-α, interleukin-1β and interleukin-6 in the medulla oblongata of the neonatal CSE rats. These results suggest that H 2 S can alleviate prenatal CSE-induced injuries of neonatal rat medulla oblongata through anti-oxidative and anti-inflammatory effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental Evidence that In Vivo Intracerebral Administration of L-2-Hydroxyglutaric Acid to Neonatal Rats Provokes Disruption of Redox Status and Histopathological Abnormalities in the Brain.

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Ribeiro, Rafael Teixeira; Zanatta, Ângela; Amaral, Alexandre Umpierrez; Leipnitz, Guilhian; de Oliveira, Francine Hehn; Seminotti, Bianca; Wajner, Moacir

2018-04-01

Tissue accumulation of L-2-hydroxyglutaric acid (L-2-HG) is the biochemical hallmark of L-2-hydroxyglutaric aciduria (L-2-HGA), a rare neurometabolic inherited disease characterized by neurological symptoms and brain white matter abnormalities whose pathogenesis is not yet well established. L-2-HG was intracerebrally administered to rat pups at postnatal day 1 (P1) to induce a rise of L-2-HG levels in the central nervous system (CNS). Thereafter, we investigated whether L-2-HG in vivo administration could disturb redox homeostasis and induce brain histopathological alterations in the cerebral cortex and striatum of neonatal rats. L-2-HG markedly induced the generation of reactive oxygen species (increase of 2',7'-dichloroflurescein-DCFH-oxidation), lipid peroxidation (increase of malondialdehyde concentrations), and protein oxidation (increase of carbonyl formation and decrease of sulfhydryl content), besides decreasing the antioxidant defenses (reduced glutathione-GSH) and sulfhydryl content in the cerebral cortex. Alterations of the activities of various antioxidant enzymes were also observed in the cerebral cortex and striatum following L-2-HG administration. Furthermore, L-2-HG-induced lipid peroxidation and GSH decrease in the cerebral cortex were prevented by the antioxidant melatonin and by the classical antagonist of NMDA glutamate receptor MK-801, suggesting the involvement of reactive species and of overstimulation of NMDA receptor in these effects. Finally, L-2-HG provoked significant vacuolation and edema particularly in the cerebral cortex with less intense alterations in the striatum that were possibly associated with the unbalanced redox homeostasis caused by this metabolite. Taken together, it is presumed that these pathomechanisms may underlie the neurological symptoms and brain abnormalities observed in the affected patients.

MR imaging of the neonatal brain: Pathologic features

International Nuclear Information System (INIS)

McArdle, C.B.; Richardson, C.J.; Nicholas, D.A.; Hayden, C.K.; Amparo, E.G.

1986-01-01

Seventy-three neonates, aged 29-43 weeks since conception, were studied. US and/or CT correlations were obtained in most infants with pathology. In the first 4-5 days after hemorrhage, US and CT were superior to MR imaging, but after that time MR imaging was the single best modality for imaging blood. In early premature infants with very watery white matter, US detected infarction and brain edema that were poorly seen on both MR imaging and CT. However, in late premature and full-term infants, MR imaging was better than CT in distinguishing between normal white matter and infarction. Only MR imaging disclosed delayed myelination in 13 term infants with hydrocephalus and severe asphyxia. MR imaging with play an important role in imaging neonates once MR imaging-compatible monitors and neonatal head coils become widely available

Microglial Cells Prevent Hemorrhage in Neonatal Focal Arterial Stroke.

Science.gov (United States)

Fernández-López, David; Faustino, Joel; Klibanov, Alexander L; Derugin, Nikita; Blanchard, Elodie; Simon, Franziska; Leib, Stephen L; Vexler, Zinaida S

2016-03-09

Perinatal stroke leads to significant morbidity and long-term neurological and cognitive deficits. The pathophysiological mechanisms of brain damage depend on brain maturation at the time of stroke. To understand whether microglial cells limit injury after neonatal stroke by preserving neurovascular integrity, we subjected postnatal day 7 (P7) rats depleted of microglial cells, rats with inhibited microglial TGFbr2/ALK5 signaling, and corresponding controls, to transient middle cerebral artery occlusion (tMCAO). Microglial depletion by intracerebral injection of liposome-encapsulated clodronate at P5 significantly reduced vessel coverage and triggered hemorrhages in injured regions 24 h after tMCAO. Lack of microglia did not alter expression or intracellular redistribution of several tight junction proteins, did not affect degradation of collagen IV induced by the tMCAO, but altered cell types producing TGFβ1 and the phosphorylation and intracellular distribution of SMAD2/3. Selective inhibition of TGFbr2/ALK5 signaling in microglia via intracerebral liposome-encapsulated SB-431542 delivery triggered hemorrhages after tMCAO, demonstrating that TGFβ1/TGFbr2/ALK5 signaling in microglia protects from hemorrhages. Consistent with observations in neonatal rats, depletion of microglia before tMCAO in P9 Cx3cr1(GFP/+)/Ccr2(RFP/+) mice exacerbated injury and induced hemorrhages at 24 h. The effects were independent of infiltration of Ccr2(RFP/+) monocytes into injured regions. Cumulatively, in two species, we show that microglial cells protect neonatal brain from hemorrhage after acute ischemic stroke. Copyright © 2016 the authors 0270-6474/16/362881-13$15.00/0.

Aluminum neurotoxicity in the rat brain

International Nuclear Information System (INIS)

Yumoto, S.; Ohashi, H.; Nagai, H.; Kakimi, S.; Ogawa, Y.; Iwata, Y.; Ishii, K.

1992-01-01

To investigate the etiology of Alzheimer's disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer's disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer's disease patients. Our results indicate that Alzheimer's disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author)

Aluminum neurotoxicity in the rat brain

Energy Technology Data Exchange (ETDEWEB)

Yumoto, S [Tokyo Univ. (Japan). Faculty of Medicine; Ohashi, H; Nagai, H; Kakimi, S; Ogawa, Y; Iwata, Y; Ishii, K

1993-12-31

To investigate the etiology of Alzheimer`s disease, we administered aluminum to healthy rats and examined the aluminum uptake in the brain and isolated brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Ten days after the last injection, Al was detected in the rat brain and in isolated brain cell nuclei by PIXE analysis. Al was also demonstrated in the brain after 15 months of oral aluminum administration. Moreover, Al was detected in the brain and isolated brain cell nuclei from the patients with Alzheimer`s disease. Silver impregnation studies revealed that spines attached to the dendritic processes of cortical nerve cells decreased remarkably after aluminum administration. Electron microscopy revealed characteristic inclusion bodies in the hippocampal nerve cells 75 days after the injection. These morphological changes in the rat brain after the aluminum administration were similar to those reportedly observed in the brain of Alzheimer`s disease patients. Our results indicate that Alzheimer`s disease is caused by irreversible accumulation of aluminum in the brain, as well as in the nuclei of brain cells. (author).

Neonatal handling induces anovulatory estrous cycles in rats

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Gomes C.M.

1999-01-01

Full Text Available Since previous work has shown that stimulation early in life decreases sexual receptiveness as measured by the female lordosis quotient, we suggested that neonatal handling could affect the function of the hypothalamus-pituitary-gonadal axis. The effects of neonatal handling on the estrous cycle and ovulation were analyzed in adult rats. Two groups of animals were studied: intact (no manipulation, N = 10 and handled (N = 11. Pups were either handled daily for 1 min during the first 10 days of life or left undisturbed. At the age of 90 days, a vaginal smear was collected daily at 9:00 a.m. and analyzed for 29 days; at 9:00 a.m. on the day of estrus, animals were anesthetized with thiopental (40 mg/kg, ip, the ovaries were removed and the oviduct was dissected and squashed between 2 glass slides. The number of oocytes of both oviductal ampullae was counted under the microscope. The average numbers for each phase of the cycle (diestrus I, diestrus II, proestrus and estrus during the period analyzed were compared between the two groups. There were no significant differences between intact and handled females during any of the phases. However, the number of handled females that showed anovulatory cycles (8 out of 11 was significantly higher than in the intact group (none out of 10. Neonatal stimulation may affect not only the hypothalamus-pituitary-adrenal axis, as previously demonstrated, but also the hypothalamus-pituitary-gonadal axis in female rats.

USE OF DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING FOR REVEALING HYPOXIC-ISCHEMIC BRAIN LESIONS IN NEONATES

Directory of Open Access Journals (Sweden)

E. V. Shimchenko

2014-01-01

Full Text Available The article presents advantages of use of diffusion-weighted magnetic resonance imaging (DW MRI for revealing hypoxic-ischemic brain lesions in neonates. The trial included 97 neonates with perinatal brain lesion who had been undergoing treatment at a resuscitation department or neonatal pathology department in the first month of life. The article shows high information value of diffusion-weighted images (DWI for diagnostics of hypoxic-ischemic lesions in comparison with regular standard modes. In the event of no structural brain lesions of neonates, pronounced increase in signal characteristics revealed by DWI indicated considerable pathophysiological alterations. Subsequently, children developed structural alterations in the form of cystic encephalomalacia with expansion of cerebrospinal fluid spaces manifested with pronounced neurological deficit. DW MRI has been offered as a method of prognosticating further neurological development of children on early stages. 

ACUTE HYPOGLYCEMIA RESULTS IN REDUCED CORTICAL NEURONAL INJURY IN THE DEVELOPING IUGR RAT

OpenAIRE

Maliszewski-Hall, Anne M.; Stein, Ariel B.; Alexander, Michelle; Ennis, Kathleen; Rao, Raghavendra

2015-01-01

Background Hypoglycemia (HG) is common in IUGR neonates. In normally grown (NG) neonatal rats, acute HG causes neuronal injury in the brain, cerebral cortex more vulnerable than the hippocampus (HPC). We hypothesized that the IUGR brain is less vulnerable to hypoglycemia-induced injury while preserving the regional variation in vulnerability. Methods We induced IUGR via bilateral uterine artery ligation on gestational day 19 (term 22d) rats. On postnatal day 14, insulin-induced HG of equivale...

Neurobehavioral Deficits in a Rat Model of Recurrent Neonatal Seizures Are Prevented by a Ketogenic Diet and Correlate with Hippocampal Zinc/Lipid Transporter Signals.

Science.gov (United States)

Tian, Tian; Ni, Hong; Sun, Bao-liang

2015-10-01

The ketogenic diet (KD) has been shown to be effective as an antiepileptic therapy in adults, but it has not been extensively tested for its efficacy in neonatal seizure-induced brain damage. We have previously shown altered expression of zinc/lipid metabolism-related genes in hippocampus following penicillin-induced developmental model of epilepsy. In this study, we further investigated the effect of KD on the neurobehavioral and cognitive deficits, as well as if KD has any influence in the activity of zinc/lipid transporters such as zinc transporter 3 (ZnT-3), MT-3, ApoE, ApoJ (clusterin), and ACAT-1 activities in neonatal rats submitted to flurothyl-induced recurrent seizures. Postnatal day 9 (P9), 48 Sprague-Dawley rats were randomly assigned to two groups: flurothyl-induced recurrent seizure group (EXP) and control group (CONT). On P28, they were further randomly divided into the seizure group without ketogenic diet (EXP1), seizure plus ketogenic diet (EXP2), the control group without ketogenic diet (CONT1), and the control plus ketogenic diet (CONT2). Neurological behavioral parameters of brain damage (plane righting reflex, cliff avoidance reflex, and open field test) were observed from P35 to P49. Morris water maze test was performed during P51-P57. Then hippocampal mossy fiber sprouting and the protein levels of ZnT3, MT3, ApoE, CLU, and ACAT-1 were detected by Timm staining and Western blot analysis, respectively. Flurothyl-induced neurobehavioral toxicology and aberrant mossy fiber sprouting were blocked by KD. In parallel with these behavioral changes, rats treated with KD (EXP2) showed a significant down-regulated expression of ZnT-3, MT-3, ApoE, clusterin, and ACAT-1 in hippocampus when compared with the non-KD-treated EXP1 group. Our findings provide support for zinc/lipid transporter signals being potential targets for the treatment of neonatal seizure-induced brain damage by KD.

Sepsis-induced alteration in T-cell Ca(2+) signaling in neonatal rats.

Science.gov (United States)

Alattar, M H; Ravindranath, T M; Choudhry, M A; Muraskas, J K; Namak, S Y; Dallal, O; Sayeed, M M

2001-01-01

Sepsis-induced suppression in T-cell proliferation follows deranged Ca(2+) signaling in adult rats. In preliminary studies, we observed suppression in T-cell proliferation in septic neonatal rats as well. In this study, we assessed splenic T-cell cytosolic Ca(2+) concentration, [Ca(2+)](i), as its elevation plays an important role in T-cell proliferation. Also, we investigated the role of PGE(2) in sepsis-related changes in T-cell [Ca(2+)](i) in animals pretreated with cyclooxygenase-1 (COX-1) inhibitor (resveratrol) and cyclooxygenase-2 (COX-2) inhibitor (NS-398). Sepsis was induced in 15-day-old rat pups by intraperitoneal implantation of fecal pellets containing Escherichia coli and Bacteroides fragilis. The sham group consisted of pups implanted with sterile fecal pellets. Septic and sham pups were sacrificed 24 h after implantation and their spleens were removed. The spleens from sham and septic pups, along with spleens from unoperated control pups, were processed for single cell suspensions, and T cells were isolated using nylon wool columns. Fura-2 fluorophotometry was employed for the measurement of [Ca(2+)](i) (in nM units) in T cells stimulated with concanavalin A (ConA). Our results show that ConA-mediated T-cell [Ca(2+)](i) response is significantly suppressed in septic neonatal rats. Pretreatment of pups with COX-2, but not COX-1 inhibitor, prevented the decrease in the [Ca(2+)](i) response. These findings suggest that PGE(2) might induce the attenuation in T-cell Ca(2+) signaling during sepsis in neonatal rats. Copyright 2001 S. Karger AG, Basel

MRI findings of brain damage due to neonatal hypoglycemia

International Nuclear Information System (INIS)

Wang Lu; Fan Guoguang; Ji Xu; Sun Baohai; Guo Qiyong

2009-01-01

Objective: To report the MRI findings of brain damage observed in neonatal patients who suffered from isolated hypoglycemia and to explore the value of diffusion-weighted imaging(DWI) in early detection of neonatal hypoglycemic brain injury. Methods: Twelve neonates with isolated hypoglycemia (10 of the 12 were diagnosed to suffer from hypoglycemic encephalopathy) were enrolled in this study. They were first scanned at age from 3 days to 10 days with T 1 WI, T 2 WI and DWI(b is 0 s/mm 2 , 1000 s/mm 2 ), and 4 of them were then scanned from 7 days to 10 days following the initial scan. All acquired MR images were retrospectively analysed. Results: First series of DWI images showed distinct hyperintense signal in 11 cases in several areas including bilateral occipital cortex (2 cases), right occipital cortex (1 case), left occipital cortex and subcortical white matter(1 case), bilateral occipital cortex and subcortical white matter (2 cases), bilateral parieto-occipital cortex (2 cases), bilateral parieto-occipital cortex and subcortical white matter(2 cases), the splenium of corpus callosum (4 cases), bilateral corona radiata( 2 cases), left caudate nucleus and globus pallidus (1 case), bilateral thalamus (1 case), bilaterally posterior limb of internal capsule (1 case). In the initial T 1 WI and T 2 WI images, there were subtle hypointensity in the damaged cortical areas (3 cases), hyperintensity in the bilaterally affected occipital cortex( 1 case) on T 1 weighted images, and hyperintensity in the affected cortex and subcortical white matter with poor differentiation on T 2 weighted images. The followed-up MRI of 4 cases showed regional encephalomalacia in the affected occipital lobes(4 cases), slightly hyperintensity on T 2 weighted images in the damaged occipital cortex (2 cases), extensive demyelination (1 case), disappearance of hyperintensity of the splenium of corpus callosum (1 case), and persistent hyperintensity in the splenium of corpus callosum (1 case

Prenatal methadone exposure is associated with altered neonatal brain development

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Victoria J. Monnelly

Full Text Available Methadone is used for medication-assisted treatment of heroin addiction during pregnancy. The neurodevelopmental outcome of children with prenatal methadone exposure can be sub-optimal. We tested the hypothesis that brain development is altered among newborn infants whose mothers were prescribed methadone.20 methadone-exposed neonates born after 37weeks' postmenstrual age (PMA and 20 non-exposed controls underwent diffusion MRI at mean PMA of 39+2 and 41+1weeks, respectively. An age-optimized Tract-based Spatial Statistics (TBSS pipeline was used to perform voxel-wise statistical comparison of fractional anisotropy (FA data between exposed and non-exposed neonates.Methadone-exposed neonates had decreased FA within the centrum semiovale, inferior longitudinal fasciculi (ILF and the internal and external capsules after adjustment for GA at MRI (p<0.05, TFCE corrected. Median FA across the white matter skeleton was 12% lower among methadone-exposed infants. Mean head circumference (HC z-scores were lower in the methadone-exposed group (−0.52 (0.99 vs 1.15 (0.84, p<0.001; after adjustment for HC z-scores, differences in FA remained in the anterior and posterior limbs of the internal capsule and the ILF. Polydrug use among cases was common.Prenatal methadone exposure is associated with microstructural alteration in major white matter tracts, which is present at birth and is independent of head growth. Although the findings cannot be attributed to methadone per se, the data indicate that further research to determine optimal management of opioid use disorder during pregnancy is required. Future studies should evaluate childhood outcomes including infant brain development and long-term neurocognitive function. Keywords: Prenatal, Methadone, Brain, Neonate, MRI, Opioid

Impaired hypoxic ventilatory response following neonatal sustained and subsequent chronic intermittent hypoxia in rats.

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Mayer, C A; Ao, J; Di Fiore, J M; Martin, R J; MacFarlane, P M

2013-06-15

Neonatal chronic intermittent hypoxia (CIH) enhances the ventilatory sensitivity to acute hypoxia (acute hypoxic ventilatory response, HVR), whereas sustained hypoxia (SH) can have the opposite effect. Therefore, we investigated whether neonatal rats pre-treated with SH prior to CIH exhibit a modified HVR. Rat pups were exposed to CIH (5% O2/5min, 8h/day) between 6 and 15 days of postnatal age (P6-15) after pre-treatment with either normoxia or SH (11% O2; P1-5). Using whole-body plethysmography, the acute (5min, 10% O2) HVR at P16 (1 day post-CIH) was unchanged following CIH (67.9±6.7% above baseline) and also SH (58.8±10.5%) compared to age-matched normoxic rats (54.7±6.3%). In contrast, the HVR was attenuated (16.5±6.0%) in CIH exposed rats pre-treated with SH. These data suggest that while neonatal SH and CIH alone have little effect on the magnitude of the acute HVR, their combined effects impose a synergistic disturbance to postnatal development of the HVR. These data could provide important insight into the consequences of not maintaining adequate levels of oxygen saturation during the early neonatal period, especially in vulnerable preterm infants susceptible to frequent bouts of hypoxemic events (CIH) that are commonly associated with apnea of prematurity. Copyright © 2013 Elsevier B.V. All rights reserved.

Can induced hypothermia be assured during brain MRI in neonates with hypoxic-ischemic encephalopathy?

International Nuclear Information System (INIS)

Wintermark, Pia; Labrecque, Michelle; Hansen, Anne; Warfield, Simon K.; DeHart, Stephanie

2010-01-01

Until now, brain MRIs in asphyxiated neonates who are receiving therapeutic hypothermia have been performed after treatment is complete. However, there is increasing interest in utilizing early brain MRI while hypothermia is still being provided to rapidly understand the degree of brain injury and possibly refine neuroprotective strategies. This study was designed to assess whether therapeutic hypothermia can be maintained while performing a brain MRI. Twenty MRI scans were obtained in 12 asphyxiated neonates while they were treated with hypothermia. The median difference between esophageal temperature on NICU departure and return was 0.1 C (range: -0.8 to 0.8 C). We found that therapeutic hypothermia can be safely and reproducibly maintained during a brain MRI. Hypothermia treatment should not prevent obtaining an early brain MRI if clinically indicated. (orig.)

Can induced hypothermia be assured during brain MRI in neonates with hypoxic-ischemic encephalopathy?

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Wintermark, Pia [Children' s Hospital Boston, Division of Newborn Medicine, Boston, MA (United States); Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); Montreal Children' s Hospital, Division of Newborn Medicine, Montreal, QC (Canada); Labrecque, Michelle; Hansen, Anne [Children' s Hospital Boston, Division of Newborn Medicine, Boston, MA (United States); Warfield, Simon K.; DeHart, Stephanie [Children' s Hospital Boston, Department of Radiology, Boston, MA (United States)

2010-12-15

Until now, brain MRIs in asphyxiated neonates who are receiving therapeutic hypothermia have been performed after treatment is complete. However, there is increasing interest in utilizing early brain MRI while hypothermia is still being provided to rapidly understand the degree of brain injury and possibly refine neuroprotective strategies. This study was designed to assess whether therapeutic hypothermia can be maintained while performing a brain MRI. Twenty MRI scans were obtained in 12 asphyxiated neonates while they were treated with hypothermia. The median difference between esophageal temperature on NICU departure and return was 0.1 C (range: -0.8 to 0.8 C). We found that therapeutic hypothermia can be safely and reproducibly maintained during a brain MRI. Hypothermia treatment should not prevent obtaining an early brain MRI if clinically indicated. (orig.)

Characterisation of an in vitro blood-brain barrier model based on primary porcine capillary endothelial cells in monoculture or co-culture with primary rat or porcine astrocytes and pericytes

DEFF Research Database (Denmark)

Thomsen, Louiza Bohn; Larsen, Annette Burkhart; Moos, Torben

to in vivo such as efflux transporters, tight junction proteins, and high transendothelial electric resistance (TEER). Primary BCECs are isolated from a variety of mammals such as rats, mice, cattle and pigs. Often bovine and porcine BCECs are cultured in monoculture or in co-culture with rat astrocytes......In vitro blood-brain barrier (BBB) models based on primary brain capillary endothelial cells (BCECs) in monoculture or in co-culture with primary astrocytes and pericytes are often applied for studying physiology of the BBB. Primary BCECs retain many morphological and biochemical properties similar...... obtained from neonatal rats which have been shown to strengthen the barrier properties of the BCECs. In this study, brain endothelial cells (PBECs), astrocytes and pericytes are isolated from pig brains donated by the local abattoir. The brains are from 6 month old domestic pigs. The availability and high...

Brain single photon emission computed tomography in neonates

International Nuclear Information System (INIS)

Denays, R.; Van Pachterbeke, T.; Tondeur, M.

1989-01-01

This study was designed to rate the clinical value of [ 123 I]iodoamphetamine (IMP) or [ 99m Tc] hexamethyl propylene amine oxyme (HM-PAO) brain single photon emission computed tomography (SPECT) in neonates, especially in those likely to develop cerebral palsy. The results showed that SPECT abnormalities were congruent in most cases with structural lesions demonstrated by ultrasonography. However, mild bilateral ventricular dilatation and bilateral subependymal porencephalic cysts diagnosed by ultrasound were not associated with an abnormal SPECT finding. In contrast, some cortical periventricular and sylvian lesions and all the parasagittal lesions well visualized in SPECT studies were not diagnosed by ultrasound scans. In neonates with subependymal and/or intraventricular hemorrhage the existence of a parenchymal abnormality was only diagnosed by SPECT. These results indicate that [ 123 I]IMP or [ 99m Tc]HM-PAO brain SPECT shows a potential clinical value as the neurodevelopmental outcome is clearly related to the site, the extent, and the number of cerebral lesions. Long-term clinical follow-up is, however, mandatory in order to define which SPECT abnormality is associated with neurologic deficit

Involvement of the JNK/FOXO3a/Bim Pathway in Neuronal Apoptosis after Hypoxic-Ischemic Brain Damage in Neonatal Rats.

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Deyuan Li

Full Text Available c-Jun N-terminal kinase (JNK plays a key role in the regulation of neuronal apoptosis. Previous studies have revealed that forkhead transcription factor (FOXO3a is a critical effector of JNK-mediated tumor suppression. However, it is not clear whether the JNK/FOXO3a pathway is involved in neuronal apoptosis in the developing rat brain after hypoxia-ischemia (HI. In this study, we generated an HI model using postnatal day 7 rats. Fluorescence immunolabeling and Western blot assays were used to detect the distribution and expression of total and phosphorylated JNK and FOXO3a and the pro-apoptotic proteins Bim and CC3. We found that JNK phosphorylation was accompanied by FOXO3a dephosphorylation, which induced FOXO3a translocation into the nucleus, resulting in the upregulation of levels of Bim and CC3 proteins. Furthermore, we found that JNK inhibition by AS601245, a specific JNK inhibitor, significantly increased FOXO3a phosphorylation, which attenuated FOXO3a translocation into the nucleus after HI. Moreover, JNK inhibition downregulated levels of Bim and CC3 proteins, attenuated neuronal apoptosis and reduced brain infarct volume in the developing rat brain. Our findings suggest that the JNK/FOXO3a/Bim pathway is involved in neuronal apoptosis in the developing rat brain after HI. Agents targeting JNK may offer promise for rescuing neurons from HI-induced damage.

Neonatal brain MRI: how reliable is the radiologist's eye?

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Morel, B. [A. Trousseau Hospital APHP, Pediatric Radiology, Paris (France); LTCI, CNRS, Telecom ParisTech, Universite Paris-Saclay, Paris (France); Antoni, G.; Teglas, J.P. [INSERM, CESP Centre for Research in Epidemiology and Population Health, U1018, Reproduction and Child Development, Villejuif (France); Bloch, I. [LTCI, CNRS, Telecom ParisTech, Universite Paris-Saclay, Paris (France); Adamsbaum, C. [Paris Sud University, Pediatric Radiology Department Bicetre Hospital APHP, Faculty of Medicine, Paris (France)

2016-02-15

White matter (WM) analysis in neonatal brain magnetic resonance imaging (MRI) is challenging, as demonstrated by the issue of diffuse excessive high signal intensity (DEHSI). We evaluated the reliability of the radiologist's eye in this context. Three experienced observers graded the WM signal intensity on axial T2-weighted 1.5T images from 60 different premature newborns on 2 occasions 4 weeks apart with a semi-quantitative classification under identical viewing conditions. The intra- and inter-observer correlation coefficients were fair to moderate (Fleiss' kappa between 0.21 and 0.60). This is a serious limitation of which we need to be aware, as it can lead to contradictory conclusions in the challenging context of term-equivalent age brain MRI in premature infants. These results highlight the need for a semiautomatic tool to help in objectively analyzing MRI signal intensity in the neonatal brain. (orig.)

Effects of repeated anesthesia by thiopental in neonatal period on PTZ-induced convulsions and pain responses during maturation in rats

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Fatemeh Faghih Majidi

2012-06-01

Full Text Available Introduction: General anesthetics during critical periods of brain development may cause some seriousmalformations or side effects. Anesthetic drugs can involve in the brain development and synaptogenesis atthe critical period of development. There are some controversy with regards the effects of(neurodegenerative or neuroprotective barbiturates on brain. The aim of the present study was toinvestigate the possible relation between repeated induced thiopental (a GABAA agonist anesthesia at thepostnatal period and pentylentetrazol-induced convulsions and pain responses in adult in the Wistar rats.Materials and methods: 40 male neonate rats were divided into experimental and sham groups. Theexperimental group (n=20 was deeply anesthetized with thiopental (30 mg/kg daily during 10 to 20-daysof post- natal period and physiologic serum was used for sham animals. After maturation of male rats, thePTZ-induced seizures were induced by daily interapritoneally injection of PTZ (45 mg/kg, and thelatency of the appearance of generalized epileptiform behaviors was recorded. Pain responses were alsoevaluated using tail-flick and formalin tests.Results: No significant differences were found in the lantency of the appearance of behaviouralconvulsions and pain sensitivity between experimental and sham groups.Conclusion: Our findings indicate that prior exposure to thiopental during nenonatal stage has no effectson PTZ-induced seizures and also pain responses after maturation. Developmental compensatorymechanisms may protect the brian against the possible damage that induced by repeated thipopental duringneonatal period.

Magnesium sulfate versus esomeprazole impact on the neonates of preeclamptic rats.

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Shafik, Amani N; Khattab, Mahmoud A; Osman, Ahmed H

2018-06-01

Preeclampsia represents a major complication of pregnancy, associated with greater maternal and fetal complications. We compared the effects of esomeprazole (a proton pump inhibitor) and magnesium sulfate (MgSO4) on the deleterious effects observed on the mother and neonates in experimentally induced preeclampsia in rats. Preeclampsia was induced in pregnant rats with NG-nitro-l-arginine methyl ester (L-NAME) starting from day 10-till end of pregnancy. Pregnant rats were divided into four groups: control pregnant; untreated preeclampsia; preeclamptic rats treated with MgSO4 and preeclamptic treated with esomeprazole. Treatment was started on day 14 and continued until end of pregnancy. Systolic blood pressure, gestation duration, the total number of pups/fetal resorption, pups birth weight, and histopathology examination of the pup's organs were recorded. In comparison with the L-NAME group, the MgSO4 and esomeprazole treatment reduced the values of systolic blood pressure; MgSO4 normalized gestational duration while esomeprazole prolonged it (post-term pregnancy); both restored number of delivered pups; with no statistical differences between the numbers of died pups between the four groups studied while with esomeprazole, out of 10 pregnant females, 2 of them had complete intrauterine fetal resorption; esomeprazole normalized birth weight and histological structure of fetal liver, kidney, and brain. On the other side, MgSO4 treatment gave rise to lower than normal birth weight and minimal tissue damage. Esomeprazole and MgSO4 improved systolic blood pressure, prevented preterm labor and restored numbers of pups delivered and fetal weight. Esomeprazole prolonged gestational period post-term with subsequent improving reproductive outcome. Copyright © 2018 Elsevier B.V. All rights reserved.

Stimulation of 5-HT2A receptors recovers sensory responsiveness in acute spinal neonatal rats.

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Swann, Hillary E; Kauer, Sierra D; Allmond, Jacob T; Brumley, Michele R

2017-02-01

Quipazine is a 5-HT 2A -receptor agonist that has been used to induce motor activity and promote recovery of function after spinal cord injury in neonatal and adult rodents. Sensory stimulation also activates sensory and motor circuits and promotes recovery after spinal cord injury. In rats, tail pinching is an effective and robust method of sacrocaudal sensory afferent stimulation that induces motor activity, including alternating stepping. In this study, responsiveness to a tail pinch following treatment with quipazine (or saline vehicle control) was examined in spinal cord transected (at midthoracic level) and intact neonatal rats. Rat pups were secured in the supine posture with limbs unrestricted. Quipazine or saline was administered intraperitoneally and after a 10-min period, a tail pinch was administered. A 1-min baseline period prior to tail-pinch administration and a 1-min response period postpinch was observed and hind-limb motor activity, including locomotor-like stepping behavior, was recorded and analyzed. Neonatal rats showed an immediate and robust response to sensory stimulation induced by the tail pinch. Quipazine recovered hind-limb movement and step frequency in spinal rats back to intact levels, suggesting a synergistic, additive effect of 5-HT-receptor and sensory stimulation in spinal rats. Although levels of activity in spinal rats were restored with quipazine, movement quality (high vs. low amplitude) was only partially restored. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Regional alterations of brain biogenic amines and GABA/glutamate levels in rats following chronic lead exposure during neonatal development

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Shailesh Kumar, M V; Desiraju, T [National Inst. of Mental Health and Neuro Sciences, Bangalore (India). Dept. of Neurophysiology

1990-06-01

Wistar rat pups were administered either a high dose of lead acetate (400 {mu}g lead-g body weight/day) or a low dose (100 {mu}g lead/g body weight/day) by gastric intubation, from 2 days through 60 days of age. The rats on both these doses exhibited statistically significant decreases in body and brain weights throughout the lead treatment period. A group of rats on high dose was also rehabilitated by discontinuing the lead from 60 days of age. In these rats, at 160 days of age, the body weight but not the brain weight recovered to normal levels. During the lead intake, the rats on high dose revealed significant elevations in the levels of noradrenaline (NA) in the hippocampus (HI), cerebellum (CE), hypothalamus (HY), brainstem (BS), and accumbens-striatum (SA). The elevated levels in all the above regions except in the HY persisted even after rehabilitation. The dopamine (DA) levels changed significantly in opposite directions in HY (elevation) and BS (reduction) during the lead treatment, and the HY recovered after rehabilitation. Under lead, the serotonin (5HT) levels were elevated significantly in the HI, BS and MC (motor cortex), while after rehabilitation the abnormality persisted only in the MC. Low dose lead treatment was also effective on the same areas of brain. In the low dose group, estimation of the levels of GABA and glutamate were also done, and a significant decrease of GABA in CE and glutamate in MC was observed. The differences observed in the neurotoxic effects (none or significant) of lead in the different regions for each of the transmitters (NA, DA, 5HT) supports the interesting conclusion that the vulnerability of the axon terminals of any given type is dependent on some regional factors, although the projections of the different regions originate from an apparently similar category of neurons in the brain stem. (orig.).

Effects of different endocrine disruptor (EDC) mixtures on gene expression in neonatal rat brain regions

DEFF Research Database (Denmark)

Lichtensteiger, Walter; Bassetti-Gaille, Catherine; Faass, Oliver

2013-01-01

Sexual brain differentiation is a potential EDC target. It depends on a combination of estrogen receptor- and androgen receptor-mediated effects in males and on estrogens in females. It is not known how these processes are affected by real-world mixtures of EDCs. We investigated the effect of three...... EDC mixtures on gene expression in developing brain. Amix (8 anti-androgenic chemicals), Emix (4 estrogenic chemicals) and Tmix (Amix + Emix + paracetamol recently identified as anti-androgenic) were administered by oral gavage to rat dams from gestational day 7 until weaning, at doses corresponding...... to 450×, 200× and 100× high end human intakes (S. Christiansen et al., 2012. International Journal of Andrology 35, 303). At postnatal day 6, during the last part of sexual brain differentiation, exon microarray analyses were performed in medial preoptic area (MPO) in the highest dose group, and real...

Cardiac tolerance to ischemia in neonatal spontaneously hypertensive rats

Czech Academy of Sciences Publication Activity Database

Charvátová, Z.; Ošťádalová, Ivana; Zicha, Josef; Kuneš, Jaroslav; Maxová, H.; Ošťádal, Bohuslav

2012-01-01

Roč. 61, Suppl.1 (2012), S145-S153 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : neonatal spontaneously hypertensive rats * contractile function * ischemic preconditioning * chronic hypoxia Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.531, year: 2012

Effects of sciatic-conditioned medium on neonatal rat retinal cells in vitro

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Torres P.M.M.

1998-01-01

Full Text Available Schwann cells produce and release trophic factors that induce the regeneration and survival of neurons following lesions in the peripheral nerves. In the present study we examined the in vitro ability of developing rat retinal cells to respond to factors released from fragments of sciatic nerve. Treatment of neonatal rat retinal cells with sciatic-conditioned medium (SCM for 48 h induced an increase of 92.5 ± 8.8% (N = 7 for each group in the amount of total protein. SCM increased cell adhesion, neuronal survival and glial cell proliferation as evaluated by morphological criteria. This effect was completely blocked by 2.5 µM chelerythrine chloride, an inhibitor of protein kinase C (PKC. These data indicate that PKC activation is involved in the effect of SCM on retinal cells and demonstrate that fragments of sciatic nerve release trophic factors having a remarkable effect on neonatal rat retinal cells in culture.

Adenosine A1 receptors contribute to immune regulation after neonatal hypoxic ischemic brain injury

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Winerdal, Max; Winerdal, Malin E.; Wang, Ying-Qing; Fredholm, Bertil B.; Winqvist, Ola; Ådén, Ulrika

2015-01-01

Neonatal brain hypoxic ischemia (HI) often results in long-term motor and cognitive impairments. Post-ischemic inflammation greatly effects outcome and adenosine receptor signaling modulates both HI and immune cell function. Here, we investigated the influence of adenosine A1 receptor deficiency (A1R−/−) on key immune cell populations in a neonatal brain HI model. Ten-day-old mice were subjected to HI. Functional outcome was assessed by open locomotion and beam walking test and infarction siz...

Environmentally persistent free radicals induce airway hyperresponsiveness in neonatal rat lungs

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Lominiki Slawo

2011-03-01

Full Text Available Abstract Background Increased asthma risk/exacerbation in children and infants is associated with exposure to elevated levels of ultrafine particulate matter (PM. The presence of a newly realized class of pollutants, environmentally persistent free radicals (EPFRs, in PM from combustion sources suggests a potentially unrecognized risk factor for the development and/or exacerbation of asthma. Methods Neonatal rats (7-days of age were exposed to EPFR-containing combustion generated ultrafine particles (CGUFP, non-EPFR containing CGUFP, or air for 20 minutes per day for one week. Pulmonary function was assessed in exposed rats and age matched controls. Lavage fluid was isolated and assayed for cellularity and cytokines and in vivo indicators of oxidative stress. Pulmonary histopathology and characterization of differential protein expression in lung homogenates was also performed. Results Neonates exposed to EPFR-containing CGUFP developed significant pulmonary inflammation, and airway hyperreactivity. This correlated with increased levels of oxidative stress in the lungs. Using differential two-dimensional electrophoresis, we identified 16 differentially expressed proteins between control and CGUFP exposed groups. In the rats exposed to EPFR-containing CGUFP; peroxiredoxin-6, cofilin1, and annexin A8 were upregulated. Conclusions Exposure of neonates to EPFR-containing CGUFP induced pulmonary oxidative stress and lung dysfunction. This correlated with alterations in the expression of various proteins associated with the response to oxidative stress and the regulation of glucocorticoid receptor translocation in T lymphocytes.

[Effects of intrauterine cigarette smoking exposure on expression of 3-mercaptopyruvate sulfurtransferase in medulla oblongata of neonatal rats].

Science.gov (United States)

Nie, Li-Hong; Hu, Ya-Jie; Li, Xian-Ke; Xue, Lian; Jia, Qing-Yi; Yang, Yi-Wen; Zheng, Yu

2013-07-01

To investigate the expression of 3-mercaptopyruvate sulfurtransferase (3MST) in medulla oblongata of neonatal rats and effects of intrauterine cigarette exposure on its expression. Sprague Dawley pregnant rats were randomly divided into 2 groups, control group and cigarette smoke exposure group (n = 8). 3MST mRNA and protein expression in medulla oblongata of neonatal rats were analysed by RT-PCR and Western blot, respectively, and the expression of 3MST in the neurons of respiratory-related nuclei in medulla oblongata of neonatal rats was investigated with immunohistochemical technique. The RT-PCR and Western blot analyses showed that 3MST mRNA and protein were expressed in the medulla oblogata of neonatal rats and intrauterine cigarette exposure promoted their expression (P < 0.05). Immunohistochemical staining indicated that 3MST existed in the neurons of pre-Bötzinger complex (pre-BötC), hypoglossal nucleus (12N), ambiguous nucleus (Amb), facial nucleus (FN) and nucleus tractus solitarius (NTS) in control group of the animals and the mean optical densities of 3MST-positive neurons in the pre-BötC, 12N, Amb and FN, but not NTS, were significantly increased in cigarette smoke exposure group (P < 0.05). 3MST exists in the neurons of medullary respiratory nuclei of neonatal rats and its expression can be up-regulated by intrauterine cigarette exposure, suggesting that the 3MST-H2S pathway may be involved in protection of medullary respiratory centers against injury induced by intrauterine cigarette exposure.

Effect of propofol in the immature rat brain on short- and long-term neurodevelopmental outcome.

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Tanja Karen

Full Text Available BACKGROUND: Propofol is commonly used as sedative in newborns and children. Recent experimental studies led to contradictory results, revealing neurodegenerative or neuroprotective properties of propofol on the developing brain. We investigated neurodevelopmental short- and long-term effects of neonatal propofol treatment. METHODS: 6-day-old Wistar rats (P6, randomised in two groups, received repeated intraperitoneal injections (0, 90, 180 min of 30 mg/kg propofol or normal saline and sacrificed 6, 12 and 24 hrs following the first injection. Cortical and thalamic areas were analysed by Western blot and quantitative real-time PCR (qRT-PCR for expression of apoptotic and neurotrophin-dependent signalling pathways. Long-term effects were assessed by Open-field and Novel-Object-Recognition at P30 and P120. RESULTS: Western blot analyses revealed a transient increase of activated caspase-3 in cortical, and a reduction of active mitogen-activated protein kinases (ERK1/2, AKT in cortical and thalamic areas. qRT-PCR analyses showed a down-regulation of neurotrophic factors (BDNF, NGF, NT-3 in cortical and thalamic regions. Minor impairment in locomotive activity was observed in propofol treated adolescent animals at P30. Memory or anxiety were not impaired at any time point. CONCLUSION: Exposing the neonatal rat brain to propofol induces acute neurotrophic imbalance and neuroapoptosis in a region- and time-specific manner and minor behavioural changes in adolescent animals.

Prolonged ketamine exposure induces increased activity of the GluN2B-containing N-methyl-d-aspartate receptor in the anterior cingulate cortex of neonatal rats.

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Kokane, Saurabh S; Gong, Kerui; Jin, Jianhui; Lin, Qing

2017-09-01

Ketamine is a commonly used anesthetic among pediatric patients due to its high efficacy. However, it has been demonstrated by several preclinical studies that, widespread accelerated programmed death of neurons (neuroapoptosis) occurs due to prolonged or repeated exposure to ketamine specifically in the neonatal brain. Therefore, an emphasis on understanding the molecular mechanisms underlying this selective vulnerability of the neonatal brain to ketamine-induced neuroapoptosis becomes important in order to identify potential therapeutic targets, which would help prevent or at least ameliorate this neuroapoptosis. In this study, we demonstrated that repeated ketamine administration (6 injections of 20mg/kg dose given over 12h time period) in neonatal (postnatal day 7; PND 7) Sprague-Dawley rats induced a progressive increase in N-methyl-d-aspartate receptor (NMDAR)-mediated excitatory postsynaptic currents (EPSCs) in the neurons of the anterior cingulate cortex (ACC) for up to 6h after the last ketamine dose. Specifically, we observed that the increased EPSCs were largely mediated by GluN2B-containing NMDARs in the neurons of the ACC. Along with increased synaptic transmission, there was also a significant increase in the expression of the GluN2B-containing NMDARs as well. Taken together, these results showed that after repeated exposure to ketamine, the synaptic transmission mediated by GluN2B-containing NMDARs was significantly increased in the neonatal brain. This was significant as it showed for the first time that ketamine had subunit-specific effects on GluN2B-containing NMDARs, potentially implicating the involvement of these subunits in the increased vulnerability of immature neurons of the neonatal brain to ketamine-induced neuroapoptosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Testosterone potentiates the hypoxic ventilatory response of adult male rats subjected to neonatal stress.

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Fournier, Sébastien; Gulemetova, Roumiana; Joseph, Vincent; Kinkead, Richard

2014-05-01

Neonatal stress disrupts development of homeostatic systems. During adulthood, male rats subjected to neonatal maternal separation (NMS) are hypertensive and show a larger hypoxic ventilatory response (HVR), with greater respiratory instability during sleep. Neonatal stress also affects sex hormone secretion; hypoxia increases circulating testosterone of NMS (but not control) male rats. Given that these effects of NMS are not observed in females, we tested the hypothesis that testosterone elevation is necessary for the stress-related increase of the HVR in adult male rats. Pups subjected to NMS were placed in an incubator for 3 h per day from postnatal day 3 to 12. Control pups remained undisturbed. Rats were reared until adulthood, and the HVR was measured by plethysmography (fractional inspired O2 = 0.12, for 20 min). We used gonadectomy to evaluate the effects of reducing testosterone on the HVR. Gonadectomy had no effect on the HVR of control animals but reduced that of NMS animals below control levels. Immunohistochemistry was used to quantify androgen receptors in brainstem areas involved in the HVR. Androgen receptor expression was generally greater in NMS rats than in control rats; the most significant increase was noted in the caudal region of the nucleus tractus solitarii. We conclude that the abnormal regulation of testosterone is important in stress-related augmentation of the HVR. The greater number of androgen receptors within the brainstem may explain why NMS rats are more sensitive to testosterone withdrawal. Based on the similarities of the cardiorespiratory phenotype of NMS rats and patients suffering from sleep-disordered breathing, these results provide new insight into its pathophysiology, especially sex-based differences in its prevalence. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Nuclear ploidy of neonatal rat livers: effects of two hepatic carcinogens (mirex and dimethylnitrosamine)

International Nuclear Information System (INIS)

Carlson, J.; Abraham, R.

1985-01-01

The effect of two hepatic carcinogens, dimethylnitrosamine (DMN) (genotoxic) and mirex (epigenetic), on polyploidization in 12-d-old neonatal rats was investigated by Coulter counteranalysis and [ 3 H] thymidine uptake in isolated hepatic nuclear classes. DMN disturbed the normal ploidy development in the neonatal liver and the proportion of nuclei in the ploidy classes by inducing the premature formation of a significant population of tetraploids with a concommitant reduction in diploids. A great proportion of the replicative activity was present in tetraploid nuclei as measured by the incorporation of [ 3 H] thymidine. The labeling index and number of mitoses were also increased. In contrast to DMN, mirex had no influence on polyploidization. The neonatal rats used in these studies thus offer an opportunity to investigate in vivo the mode of action of genotoxic versus epigenetic compounds with reference to their effect on DNA

Neonatal Pain in Very Preterm Infants: Long-Term Effects on Brain, Neurodevelopment and Pain Reactivity

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Ruth Eckstein Grunau

2013-10-01

Full Text Available Effects of early life psychosocial adversity have received a great deal of attention, such as maternal separation in experimental animal models and abuse/neglect in young humans. More recently, long-term effects of the physical stress of repetitive procedural pain have begun to be addressed in infants hospitalized in neonatal intensive care. Preterm infants are more sensitive to pain and stress, which cannot be distinguished in neonates. The focus of this review is clinical studies of long-term effects of repeated procedural pain-related stress in the neonatal intensive care unit (NICU in relation to brain development, neurodevelopment, programming of stress systems, and later pain sensitivity in infants born very preterm (24–32 weeks’ gestational age. Neonatal pain exposure has been quantified as the number of invasive and/or skin-breaking procedures during hospitalization in the NICU. Emerging studies provide convincing clinical evidence for an adverse impact of neonatal pain/stress in infants at a time of physiological immaturity, rapidly developing brain microstructure and networks, as well as programming of the hypothalamic-pituitary-adrenal axis. Currently it appears that early pain/stress may influence the developing brain and thereby neurodevelopment and stress-sensitive behaviors, particularly in the most immature neonates. However, there is no evidence for greater prevalence of pain syndromes compared to children and adults born healthy at full term. In addressing associations between pain/stress and outcomes, careful consideration of confounding clinical factors related to prematurity is essential. The need for pain management for humanitarian care is widely advocated. Non-pharmacological interventions to help parents reduce their infant’s stress may be brain-protective.

Sustained neonatal hyperthyroidism in the rat affects myelination in the central nervous system.

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Marta, C B; Adamo, A M; Soto, E F; Pasquini, J M

1998-07-15

We have carried out a study of the effects of sustained neonatal hyperthyroidism on myelin and on the oligodendroglial cells, in an effort to obtain further insight into the molecular mechanisms underlying the action of thyroid hormones on the central nervous system (CNS). Expression of the mRNAs of myelin basic protein (MBP) myelin proteolipid protein (PLP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), transferrin, and c-Jun was investigated in 10- and 17-day-old normal and hyperthyroid rats, using Northern blot analysis. At 10 days of age, the levels of all the explored mRNAs were markedly higher in the experimental animals. The mRNA of transferrin showed a ninefold increase over control values, suggesting the possibility that this putative trophic factor might act as one of the mediators in the action of thyroid hormones. At 17 days of age on the other hand, the levels of all the mRNAs decreased markedly, reaching values below control, except for c-Jun, which remained higher than in normals. At 70 days of age, hyperthyroid rats showed clear evidence of myelin deficit, in agreement with previous results of our laboratories (Pasquini et al.: J Neurochem 57: Suppl S124, 1991). Immunocytochemistry of 70-day-old rat brain tissue sections showed a substantial reduction in the amount of MBP-reacting structures and a marked decrease in the number of oligodendroglial cells. Although the above-mentioned results could be the consequence, as proposed by Barres et al. (Development 120:1097-1108, 1994) and Baas et al. (Glia 19:324-332, 1997) of a premature arrest in oligodendroglial cell proliferation followed by early differentiation, the persistent high levels of expression of c-Jun, together with the dramatic decrease in the number of oligodendrocytes, suggested the possibility that prolonged hyperthyroidism could activate apoptotic mechanisms in the myelin forming cells. Using propidium iodide-labeled isolated oligodendroglial cells, we found, by flow cytometry

Neonatal stress tempers vulnerability of acute stress response in adult socially isolated rats

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Mariangela Serra

2014-06-01

Full Text Available Adverse experiences occurred in early life and especially during childhood and adolescence can have negative impact on behavior later in life and the quality of maternal care is considered a critical moment that can considerably influence the development and the stress responsiveness in offspring. This review will assess how the association between neonatal and adolescence stressful experiences such as maternal separation and social isolation, at weaning, may influence the stress responsiveness and brain plasticity in adult rats. Three hours of separation from the pups (3-14 postnatal days significantly increased frequencies of maternal arched-back nursing and licking-grooming by dams across the first 14 days postpartum and induced a long-lasting increase in their blood levels of corticosterone. Maternal separation, which per sedid not modified brain and plasma allopregnanolone and corticosterone levels in adult rats, significantly reduced social isolation-induced decrease of the levels of these hormones. Moreover, the enhancement of corticosterone and allopregnanolone levels induced by foot shock stress in socially isolated animals that were exposed to maternal separation was markedly reduced respect to that observed in socially isolated animals. Our results suggest that in rats a daily brief separation from the mother during the first weeks of life, which per se did not substantially alter adult function and reactivity of hypothalamic-pituitary-adrenal (HPA axis, elicited a significant protection versus the subsequent long-term stressful experience such that induced by social isolation from weaning. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in NeonatologyGuest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

Importance of neural mechanisms in colonic mucosal and muscular dysfunction in adult rats following neonatal colonic irritation

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Chaloner, A.; Rao, A.; Al-Chaer, E.D.; Meerveld, B. Greenwood-Van

2009-01-01

Previous studies have shown that early life trauma induced by maternal separation or colonic irritation leads to hypersensitivity to colorectal distension in adulthood. We tested the hypothesis that repetitive colorectal distension in neonates leads to abnormalities in colonic permeability and smooth muscle function in the adult rat. In neonatal rats, repetitive colorectal distension was performed on days 8, 10, and 12. As adults, stool consistency was graded from 0 (formed stool) to 3 (liqui...

Dairy fat blends high in α-linolenic acid are superior to n-3 fatty-acid-enriched palm oil blends for increasing DHA levels in the brains of young rats.

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Du, Qin; Martin, Jean-Charles; Agnani, Genevieve; Pages, Nicole; Leruyet, Pascale; Carayon, Pierre; Delplanque, Bernadette

2012-12-01

Achieving an appropriate docosahexaenoic acid (DHA) status in the neonatal brain is an important goal of neonatal nutrition. We evaluated how different dietary fat matrices improved DHA content in the brains of both male and female rats. Forty rats of each gender were born from dams fed over gestation and lactation with a low α-linolenic acid (ALA) diet (0.4% of fatty acids) and subjected for 6 weeks after weaning to a palm oil blend-based diet (10% by weight) that provided either 1.5% ALA or 1.5% ALA and 0.12% DHA with 0.4% arachidonic acid or to an anhydrous dairy fat blend that provided 1.5% or 2.3% ALA. Fatty acids in the plasma, red blood cells (RBCs) and whole brain were determined by gas chromatography. The 1.5% ALA dairy fat was superior to both the 1.5% ALA palm oil blends for increasing brain DHA (14.4% increase, PDHA due to a gender-to-diet interaction, with dairy fats attenuating the gender effect. Brain DHA was predicted with a better accuracy by some plasma and RBC fatty acids when used in combination (R(2) of 0.6) than when used individually (R(2)=0.47 for RBC n-3 docosapentaenoic acid at best). In conclusion, dairy fat blends enriched with ALA appear to be an interesting strategy for achieving optimal DHA levels in the brain of postweaning rats. Human applications are worth considering. Copyright © 2012 Elsevier Inc. All rights reserved.

Environmental enrichment decreases asphyxia-induced neurobehavioral developmental delay in neonatal rats.

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Kiss, Peter; Vadasz, Gyongyver; Kiss-Illes, Blanka; Horvath, Gabor; Tamas, Andrea; Reglodi, Dora; Koppan, Miklos

2013-11-13

Perinatal asphyxia during delivery produces long-term disability and represents a major problem in neonatal and pediatric care. Numerous neuroprotective approaches have been described to decrease the effects of perinatal asphyxia. Enriched environment is a popular strategy to counteract nervous system injuries. The aim of the present study was to investigate whether enriched environment is able to decrease the asphyxia-induced neurobehavioral developmental delay in neonatal rats. Asphyxia was induced in ready-to-deliver mothers by removing the pups by caesarian section after 15 min of asphyxia. Somatic and neurobehavioral development was tested daily and motor coordination weekly. Our results show that rats undergoing perinatal asphyxia had a marked developmental delay and worse performance in motor coordination tests. However, pups kept in enriched environment showed a decrease in the developmental delay observed in control asphyctic pups. Rats growing up in enriched environment did not show decrease in weight gain after the first week and the delay in reflex appearance was not as marked as in control rats. In addition, the development of motor coordination was not as strikingly delayed as in the control group. Short-term neurofunctional outcome are known to correlate with long-term deficits. Our results thus show that enriched environment could be a powerful strategy to decrease the deleterious developmental effects of perinatal asphyxia.

Effects of heavy-ion radiation on the brain vascular system

International Nuclear Information System (INIS)

Yang, T.C.; Craise, L.M.; Tobias, C.A.

1985-01-01

In the laboratory, the authors have been studying the effects of heavy-ion radiation on the vascular system, using neonatal rats as a model system. They investigated the response of the brain vascular system to ionizing radiation and found that distinct petechial hemorrhages developed in the cerebral cortex within a few hours after irradiation, reached a maximum after about 13 to 24 hours, and then decreased exponentially with time. No brain hemorrhage was found in neonatal rats 12 days after irradiation. Heavy ions induce more hemorrhages than x rays for a given dose, and the RBE for 670-MeV/u neon particles ranges from about 2.0 for low doses to about 1.4 for high doses

Estrogen restores brain insulin sensitivity in ovariectomized non-obese rats, but not in ovariectomized obese rats.

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Pratchayasakul, Wasana; Chattipakorn, Nipon; Chattipakorn, Siriporn C

2014-06-01

We previously demonstrated that obesity caused the reduction of peripheral and brain insulin sensitivity and that estrogen therapy improved these defects. However, the beneficial effect of estrogen on brain insulin sensitivity and oxidative stress in either ovariectomy alone or ovariectomy with obesity models has not been determined. We hypothesized that ovariectomy alone or ovariectomy with obesity reduces brain insulin sensitivity and increases brain oxidative stress, which are reversed by estrogen treatment. Thirty female rats were assigned as either sham-operated or ovariectomized. After the surgery, each group was fed either a normal diet or high-fat diet for 12 weeks. At week 13, rats in each group received either the vehicle or estradiol for 30 days. At week 16, blood and brain were collected for determining the peripheral and brain insulin sensitivity as well as brain oxidative stress. We found that ovariectomized rats and high-fat diet fed rats incurred obesity, reduced peripheral and brain insulin sensitivity, and increased brain oxidative stress. Estrogen ameliorated peripheral insulin sensitivity in these rats. However, the beneficial effect of estrogen on brain insulin sensitivity and brain oxidative stress was observed only in ovariectomized normal diet-fed rats, but not in ovariectomized high fat diet-fed rats. Our results suggested that reduced brain insulin sensitivity and increased brain oxidative stress occurred after either ovariectomy or obesity. However, the reduced brain insulin sensitivity and the increased brain oxidative stress in ovariectomy with obesity could not be ameliorated by estrogen treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

Digital gene atlas of neonate common marmoset brain.

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Shimogori, Tomomi; Abe, Ayumi; Go, Yasuhiro; Hashikawa, Tsutomu; Kishi, Noriyuki; Kikuchi, Satomi S; Kita, Yoshiaki; Niimi, Kimie; Nishibe, Hirozumi; Okuno, Misako; Saga, Kanako; Sakurai, Miyano; Sato, Masae; Serizawa, Tsuna; Suzuki, Sachie; Takahashi, Eiki; Tanaka, Mami; Tatsumoto, Shoji; Toki, Mitsuhiro; U, Mami; Wang, Yan; Windak, Karl J; Yamagishi, Haruhiko; Yamashita, Keiko; Yoda, Tomoko; Yoshida, Aya C; Yoshida, Chihiro; Yoshimoto, Takuro; Okano, Hideyuki

2018-03-01

Interest in the common marmoset (Callithrix jacchus) as a primate model animal has grown recently, in part due to the successful demonstration of transgenic marmosets. However, there is some debate as to the suitability of marmosets, compared to more widely used animal models, such as the macaque monkey and mouse. Especially, the usage of marmoset for animal models of human cognition and mental disorders, is still yet to be fully explored. To examine the prospects of the marmoset model for neuroscience research, the Marmoset Gene Atlas (https://gene-atlas.bminds.brain.riken.jp/) provides a whole brain gene expression atlas in the common marmoset. We employ in situ hybridization (ISH) to systematically analyze gene expression in neonate marmoset brains, which allows us to compare expression with other model animals such as mouse. We anticipate that these data will provide sufficient information to develop tools that enable us to reveal marmoset brain structure, function, cellular and molecular organization for primate brain research. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Disorganization of Oligodendrocyte Development in the Layer II/III of the Sensorimotor Cortex Causes Motor Coordination Dysfunction in a Model of White Matter Injury in Neonatal Rats.

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Ueda, Yoshitomo; Misumi, Sachiyo; Suzuki, Mina; Ogawa, Shino; Nishigaki, Ruriko; Ishida, Akimasa; Jung, Cha-Gyun; Hida, Hideki

2018-01-01

We previously established neonatal white matter injury (WMI) model rat that is made by right common carotid artery dissection at postnatal day 3, followed by 6% hypoxia for 60 min. This model has fewer oligodendrocyte progenitor cells and reduced myelin basic protein (MBP) positive areas in the sensorimotor cortex, but shows no apparent neuronal loss. However, how motor deficits are induced in this model is unclear. To elucidate the relationship between myelination disturbance and concomitant motor deficits, we first performed motor function tests (gait analysis, grip test, horizontal ladder test) and then analyzed myelination patterns in the sensorimotor cortex using transmission electron microscopy (TEM) and Contactin associated protein 1 (Caspr) staining in the neonatal WMI rats in adulthood. Behavioral tests revealed imbalanced motor coordination in this model. Motor deficit scores were higher in the neonatal WMI model, while hindlimb ladder stepping scores and forelimb grasping force were comparable to controls. Prolonged forelimb swing times and decreased hindlimb paw angles on the injured side were revealed by gait analysis. TEM revealed no change in myelinated axon number and the area g-ratio in the layer II/III of the cortex. Electromyographical durations and latencies in the gluteus maximus in response to electrical stimulation of the brain area were unchanged in the model. Caspr staining revealed fewer positive dots in layers II/III of the WMI cortex, indicating fewer and/or longer myelin sheath. These data suggest that disorganization of oligodendrocyte development in layers II/III of the sensorimotor cortex relates to imbalanced motor coordination in the neonatal WMI model rat.

Importance of neural mechanisms in colonic mucosal and muscular dysfunction in adult rats following neonatal colonic irritation.

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Chaloner, A; Rao, A; Al-Chaer, E D; Greenwood-Van Meerveld, B

2010-02-01

Previous studies have shown that early life trauma induced by maternal separation or colonic irritation leads to hypersensitivity to colorectal distension in adulthood. We tested the hypothesis that repetitive colorectal distension in neonates leads to abnormalities in colonic permeability and smooth muscle function in the adult rat. In neonatal rats, repetitive colorectal distension was performed on days 8, 10, and 12. As adults, stool consistency was graded from 0 (formed stool) to 3 (liquid stool). Colonic tissue was isolated for histology and myeloperoxidase levels. The colonic mucosa was placed in modified Ussing chambers for measurements of permeability and short-circuit current responses to forskolin, electrical field stimulation, and carbachol. Segments of colonic musculature were placed in organ baths and contractile response to potassium chloride, electrical field stimulation, and carbachol were determined. In adult rats that experienced neonatal colonic irritation, no significant changes in colonic histology or myeloperoxidase activity were observed; however, stool consistency scores were increased. Mucosal permeability, measured as an increase in basal conductance, was significantly increased but no changes in short-circuit current responses were observed. In adulthood, rats that underwent colorectal distension as neonates exhibited an elevated smooth muscle contractile response to potassium chloride, but no changes in response to electrical field stimulation or carbachol. In summary, neonatal colonic irritation, shown previously to produce colonic hypersensitivity, leads to significant alterations in colonic mucosal and smooth muscle function characterized by loose stools, increased mucosal permeability, and increased smooth muscle contractility in the absence of colon inflammation in adulthood. Published by Elsevier Ltd.

Semi-quantitative Assessment of Brain Maturation by Conventional Magnetic Resonance Imaging in Neonates with Clinically Mild Hypoxic-ischemic Encephalopathy

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Gao, Jie; Sun, Qin-Li; Zhang, Yu-Miao; Li, Yan-Yan; Li, Huan; Hou, Xin; Yu, Bo-Lang; Zhou, Xi-Hui; Yang, Jian

2015-01-01

Background: Mild hypoxic-ischemic encephalopathy (HIE) injury is becoming the major type in neonatal brain diseases. The aim of this study was to assess brain maturation in mild HIE neonatal brains using total maturation score (TMS) based on conventional magnetic resonance imaging (MRI). Methods: Totally, 45 neonates with clinically mild HIE and 45 matched control neonates were enrolled. Gestated age, birth weight, age after birth and postmenstrual age at magnetic resonance (MR) scan were homogenous in the two groups. According to MR findings, mild HIE neonates were divided into three subgroups: Pattern I, neonates with normal MR appearance; Pattern II, preterm neonates with abnormal MR appearance; Pattern III, full-term neonates with abnormal MR appearance. TMS and its parameters, progressive myelination (M), cortical infolding (C), involution of germinal matrix tissue (G), and glial cell migration bands (B), were employed to assess brain maturation and compare difference between HIE and control groups. Results: The mean of TMS was significantly lower in mild HIE group than it in the control group (mean ± standard deviation [SD] 11.62 ± 1.53 vs. 12.36 ± 1.26, P < 0.001). In four parameters of TMS scores, the M and C scores were significantly lower in mild HIE group. Of the three patterns of mild HIE, Pattern I (10 cases) showed no significant difference of TMS compared with control neonates, while Pattern II (22 cases), III (13 cases) all had significantly decreased TMS than control neonates (mean ± SD 10.56 ± 0.93 vs. 11.48 ± 0.55, P < 0.05; 12.59 ± 1.28 vs. 13.25 ± 1.29, P < 0.05). It was M, C, and GM scores that significantly decreased in Pattern II, while for Pattern III, only C score significantly decreased. Conclusions: The TMS system, based on conventional MRI, is an effective method to detect delayed brain maturation in clinically mild HIE. The conventional MRI can reveal the different retardations in subtle structures and development processes

Inflammatory injury to the neonatal brain – what can we do?

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Noa eOfek-shlomai

2014-04-01

Full Text Available Abstract Perinatal brain damage is one of the leading causes of life long disability. This damage could be hypoxic-ischemic, inflammatory or both.This mini-review discusses different interventions aiming at minimizing inflammatory processes in the neonatal brain, both before and after insult. Current options of anti-inflammatory measures for neonates remain quite limited. We describe current anti-inflammatory intervention strategies such as avoiding perinatal infection and inflammation, and reducing exposure to inflammatory processes. We describe the known effects of anti-inflammatory drugs such as steroids, antibiotics, and indomethacin, and the possible anti-inflammatory role of other substances such as IL-1receptor antagonists, erythropoietin, caffeine, estradiol, insulin like growth factor and melatonin as well as endogenous protectors, and genetic regulation of inflammation. If successful, these may decrease mortality and long term morbidity among term and preterm infants.

Formation of binucleated myocardial cells in the neonatal rat. An index for growth hypertrophy

International Nuclear Information System (INIS)

Clubb, F.J. Jr.; Bishop, S.P.

1984-01-01

The purposes of this study were to characterize myocardial cell growth in neonatal rats and investigate the mechanism of binucleation in myocardial cells. To test the hypothesis that binucleated myocardial cells result from karyokinesis without cytokinesis, experiments were designed to measure the rate of DNA synthesis and the percentage of binucleated myocardial cells in neonatal rats during growth. Estimates of myocardial cell nuclear divisions were obtained from rats pulsed with tritiated thymidine at 17 days of gestation. Autoradiograms were prepared from isolated myocardial cells of rats killed at various ages postpartum, and the number of developed silver halide grains over myocardial cell nuclei was calculated. This estimated the mitotic activity of nuclei. To determine myocardial cell DNA synthesis postpartum, another set of rats were injected at various time periods with 4 hourly doses of tritiated thymidine, and hearts were fixed by perfusion 1 hour later. Labeling index of myocardial cells was calculated (labeled/total myocardial cells) from autoradiograms. Results indicated that the growth of myocardial cells in period can be divided into three phases: (a) a hyperplastic phase, (b) a transitional phase, and (c) a hypertrophic phase. Binucleation of myocardial cells was not due to fusion of mononucleated cells

Selective survival of β1-adenergic receptors in rat cerebellum following neonatal X-irradiation

International Nuclear Information System (INIS)

Minneman, K.P.; Pittman, R.N.; Wolfe, B.B.; Molinoff, P.B.

1981-01-01

To investigate the cellular localization of β 1 - and β 2 -adrenergic receptors, the effects of intermittent neonatal X-irradiation focused on the cerebellum were determined on the densities of the two subtypes of β-adrenergic receptor. This treatment destroys the late-maturing cerebellar interneurons including the granule, basket and stellate cells. The total number of β 2 -adrenergic receptors per cerebellum was reduced by 81-83% in 6- and 12-week-old X-irradiated rats. However, the number of β 1 -adrenergic receptors per cerebellum in 6- and 12-week-old X-irradiated rats was not significantly different from that in control animals. The results suggest that β 2 receptors in the rat cerebellum are primarily associated with the small interneurons destroyed by neonatal X-irradiation. The β 1 receptors may be located on a cell population which is unaffected by this treatment, possibly on cerebellar Purkinje cells. (Auth.)

Sex Differences in Behavioral Outcomes Following Temperature Modulation During Induced Neonatal Hypoxic Ischemic Injury in Rats

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Amanda L. Smith

2015-05-01

Full Text Available Neonatal hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain can cause various degrees of tissue damage, as well as subsequent cognitive/behavioral deficits such as motor, learning/memory, and auditory impairments. These outcomes frequently result from cardiovascular and/or respiratory events observed in premature infants. Data suggests that there is a sex difference in HI outcome, with males being more adversely affected relative to comparably injured females. Brain/body temperature may play a role in modulating the severity of an HI insult, with hypothermia during an insult yielding more favorable anatomical and behavioral outcomes. The current study utilized a postnatal day (P 7 rodent model of HI injury to assess the effect of temperature modulation during injury in each sex. We hypothesized that female P7 rats would benefit more from lowered body temperatures as compared to male P7 rats. We assessed all subjects on rota-rod, auditory discrimination, and spatial/non-spatial maze tasks. Our results revealed a significant benefit of temperature reduction in HI females as measured by most of the employed behavioral tasks. However, HI males benefitted from temperature reduction as measured on auditory and non-spatial tasks. Our data suggest that temperature reduction protects both sexes from the deleterious effects of HI injury, but task and sex specific patterns of relative efficacy are seen.

Sex differences in behavioral outcomes following temperature modulation during induced neonatal hypoxic ischemic injury in rats.

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Smith, Amanda L; Garbus, Haley; Rosenkrantz, Ted S; Fitch, Roslyn Holly

2015-05-22

Neonatal hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) can cause various degrees of tissue damage, as well as subsequent cognitive/behavioral deficits such as motor, learning/memory, and auditory impairments. These outcomes frequently result from cardiovascular and/or respiratory events observed in premature infants. Data suggests that there is a sex difference in HI outcome, with males being more adversely affected relative to comparably injured females. Brain/body temperature may play a role in modulating the severity of an HI insult, with hypothermia during an insult yielding more favorable anatomical and behavioral outcomes. The current study utilized a postnatal day (P) 7 rodent model of HI injury to assess the effect of temperature modulation during injury in each sex. We hypothesized that female P7 rats would benefit more from lowered body temperatures as compared to male P7 rats. We assessed all subjects on rota-rod, auditory discrimination, and spatial/non-spatial maze tasks. Our results revealed a significant benefit of temperature reduction in HI females as measured by most of the employed behavioral tasks. However, HI males benefitted from temperature reduction as measured on auditory and non-spatial tasks. Our data suggest that temperature reduction protects both sexes from the deleterious effects of HI injury, but task and sex specific patterns of relative efficacy are seen.

Extended Postnatal Brain Development in the Longest-Lived Rodent: Prolonged Maintenance of Neotenous Traits in the Naked Mole-Rat Brain.

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Orr, Miranda E; Garbarino, Valentina R; Salinas, Angelica; Buffenstein, Rochelle

2016-01-01

The naked mole-rat (NMR) is the longest-lived rodent with a maximum lifespan >31 years. Intriguingly, fully-grown naked mole-rats (NMRs) exhibit many traits typical of neonatal rodents. However, little is known about NMR growth and maturation, and we question whether sustained neotenous features when compared to mice, reflect an extended developmental period, commensurate with their exceptionally long life. We tracked development from birth to 3 years of age in the slowest maturing organ, the brain, by measuring mass, neural stem cell proliferation, axonal, and dendritic maturation, synaptogenesis and myelination. NMR brain maturation was compared to data from similar sized rodents, mice, and to that of long-lived mammals, humans, and non-human primates. We found that at birth, NMR brains are significantly more developed than mice, and rather are more similar to those of newborn primates, with clearly laminated hippocampi and myelinated white matter tracts. Despite this more mature brain at birth than mice, postnatal NMR brain maturation occurs at a far slower rate than mice, taking four-times longer than required for mice to fully complete brain development. At 4 months of age, NMR brains reach 90% of adult size with stable neuronal cytostructural protein expression whereas myelin protein expression does not plateau until 9 months of age in NMRs, and synaptic protein expression continues to change throughout the first 3 years of life. Intriguingly, NMR axonal composition is more similar to humans than mice whereby NMRs maintain expression of three-repeat (3R) tau even after brain growth is complete; mice experience an abrupt downregulation of 3R tau by postnatal day 8 which continues to diminish through 6 weeks of age. We have identified key ages in NMR cerebral development and suggest that the long-lived NMR may provide neurobiologists an exceptional model to study brain developmental processes that are compressed in common short-lived laboratory animal models.

Extended postnatal brain development in the longest-lived rodent: prolonged maintenance of neotenous traits in the naked mole-rat brain

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Miranda E. Orr

2016-11-01

Full Text Available The naked mole-rat (NMR is the longest-lived rodent with a maximum lifespan >31 years. Intriguingly, fully-grown naked mole-rats (NMRs exhibit many traits typical of neonatal rodents. However, little is known about NMR growth and maturation, and we question whether sustained neotenous features when compared to mice, reflect an extended developmental period, commensurate with their exceptionally long life. We tracked development from birth to three years of age in the slowest maturing organ, the brain, by measuring mass, neural stem cell proliferation, axonal and dendritic maturation, synaptogenesis and myelination. NMR brain maturation was compared to data from similar sized rodents, mice, and to that of long-lived mammals, humans and non-human primates. We found that at birth, NMR brains are significantly more developed than mice, and rather are more similar to those of newborn primates, with clearly laminated hippocampi and myelinated white matter tracts. Despite this more mature brain at birth than mice, postnatal NMR brain maturation occurs at a far slower rate than mice, taking four-times longer than required for mice to fully complete brain development. At four months of age, NMR brains reach 90% of adult size with stable neuronal cytostructural protein expression whereas myelin protein expression does not plateau until nine months of age in NMRs, and synaptic protein expression continues to change throughout the first three years of life. Intriguingly, NMR axonal composition is more similar to humans than mice whereby NMRs maintain expression of three-repeat (3R tau even after brain growth is complete; mice experience an abrupt downregulation of 3R tau by postnatal day 8 which continues to diminish through six weeks of age. We have identified key ages in NMR cerebral development and suggest that the long-lived NMR may provide neurobiologists an exceptional model to study brain developmental processes that are compressed in common short

Topography of Striate-Extrastriate Connections in Neonatally Enucleated Rats

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Robyn J. Laing

2013-01-01

Full Text Available It is known that retinal input is necessary for the normal development of striate cortex and its corticocortical connections, but there is little information on the role that retinal input plays in the development of retinotopically organized connections between V1 and surrounding visual areas. In nearly all lateral extrastriate areas, the anatomical and physiological representation of the nasotemporal axis of the visual field mirrors the representation of this axis in V1. To determine whether the mediolateral topography of striate-extrastriate projections is preserved in neonatally enucleated rats, we analyzed the patterns of projections resulting from tracer injections placed at different sites along the mediolateral axis of V1. We found that the correlation between the distance from injection sites to the lateral border of V1 and the distance of the labeling patterns in area 18a was strong in controls and much weaker in enucleates. Data from pairs of injections in the same animal revealed that the separation of area 18a projection fields for a given separation of injection sites was more variable in enucleated than in control rats. Our analysis of single and double tracer injections suggests that neonatal bilateral enucleation weakens, but not completely abolishes, the mediolateral topography in area 18a.

Development of acute hydrocephalus does not change brain tissue mechanical properties in adult rats, but in juvenile rats.

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Pong, Alice C; Jugé, Lauriane; Bilston, Lynne E; Cheng, Shaokoon

2017-01-01

Regional changes in brain stiffness were previously demonstrated in an experimental obstructive hydrocephalus juvenile rat model. The open cranial sutures in the juvenile rats have influenced brain compression and mechanical properties during hydrocephalus development and the extent by which closed cranial sutures in adult hydrocephalic rat models affect brain stiffness in-vivo remains unclear. The aims of this study were to determine changes in brain tissue mechanical properties and brain structure size during hydrocephalus development in adult rat with fixed cranial volume and how these changes were related to brain tissue deformation. Hydrocephalus was induced in 9 female ten weeks old Sprague-Dawley rats by injecting 60 μL of a kaolin suspension (25%) into the cisterna magna under anaesthesia. 6 sham-injected age-matched female SD rats were used as controls. MR imaging (9.4T, Bruker) was performed 1 day before and then at 3 days post injection. T2-weighted anatomical MR images were collected to quantify ventricle and brain tissue cross-sectional areas. MR elastography (800 Hz) was used to measure the brain stiffness (G*, shear modulus). Brain tissue in the adult hydrocephalic rats was more compressed than the juvenile hydrocephalic rats because the skulls of the adult hydrocephalic rats were unable to expand like the juvenile rats. In the adult hydrocephalic rats, the cortical gray matter thickness and the caudate-putamen cross-sectional area decreased (Spearman, P hydrocephalus is complex and is not solely dependent on brain tissue deformation. Further studies on the interactions between brain tissue stiffness, deformation, tissue oedema and neural damage are necessary before MRE can be used as a tool to track changes in brain biomechanics in hydrocephalus.

[In vitro generation of insulin-producing cells from the neonatal rat bone marrow mesenchymal stem cells].

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Li, Xiaohu; Huang, Haiyan; Liu, Xirong; Xia, Hongxia; Li, Mincai

2015-03-01

To observe the differentiation of the neonatal rat bone marrow mesenchymal stem cells (MSCs) into insulin-producing cells and detect the expressions of insulin, pancreatic duodenal homebox-1 (PDX-1) and nestin. MSCs were isolated from the neonatal rats and cultured in the modified medium composed of 10 μg/L human epidermal growth factor (EGF), 10 μg/L basic fibroblast growth factor (bFGF), 10 μg/L hepatocyte growth factor (HGF), 10 μg/L human B cell regulin, 20 mmol/L nicotinamide and 20 g/L B27. After the induction, the mRNA expressions of insulin, PDX-1 and nestin were examined by reverse transcription-PCR, and the insulin, PDX-1 and nestin protein levels were detected by immunocytochemistry. The insulin and PDX-1 mRNA expressions increased and the nestin mRNA expression decreased in the differentiation of the neonatal rat MSCs into insulin-producing cells. The nestin, PDX-1 and insulin proteins were co-expressed in insulin-producing cells. MSCs can be induced to differentiate into insulin-producing cells.

Morphological features of the neonatal brain support development of subsequent cognitive, language, and motor abilities.

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Spann, Marisa N; Bansal, Ravi; Rosen, Tove S; Peterson, Bradley S

2014-09-01

Knowledge of the role of brain maturation in the development of cognitive abilities derives primarily from studies of school-age children to adults. Little is known about the morphological features of the neonatal brain that support the subsequent development of abilities in early childhood, when maturation of the brain and these abilities are the most dynamic. The goal of our study was to determine whether brain morphology during the neonatal period supports early cognitive development through 2 years of age. We correlated morphological features of the cerebral surface assessed using deformation-based measures (surface distances) of high-resolution MRI scans for 33 healthy neonates, scanned between the first to sixth week of postmenstrual life, with subsequent measures of their motor, language, and cognitive abilities at ages 6, 12, 18, and 24 months. We found that morphological features of the cerebral surface of the frontal, mesial prefrontal, temporal, and occipital regions correlated with subsequent motor scores, posterior parietal regions correlated with subsequent language scores, and temporal and occipital regions correlated with subsequent cognitive scores. Measures of the anterior and middle portions of the cingulate gyrus correlated with scores across all three domains of ability. Most of the significant findings were inverse correlations located bilaterally in the brain. The inverse correlations may suggest either that a more protracted morphological maturation or smaller local volumes of neonatal brain tissue supports better performance on measures of subsequent motor, language, and cognitive abilities throughout the first 2 years of postnatal life. The correlations of morphological measures of the cingulate with measures of performance across all domains of ability suggest that the cingulate supports a broad range of skills in infancy and early childhood, similar to its functions in older children and adults. Copyright © 2014 Wiley Periodicals, Inc.

Functional neuroanatomy of executive function after neonatal brain injury in adults who were born very preterm.

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Anastasia K Kalpakidou

Full Text Available Individuals who were born very preterm (VPT; <33 gestational weeks are at risk of experiencing deficits in tasks involving executive function in childhood and beyond. In addition, the type and severity of neonatal brain injury associated with very preterm birth may exert differential effects on executive functioning by altering its neuroanatomical substrates. Here we addressed this question by investigating with functional magnetic resonance imaging (fMRI the haemodynamic response during executive-type processing using a phonological verbal fluency and a working memory task in VPT-born young adults who had experienced differing degrees of neonatal brain injury. 12 VPT individuals with a history of periventricular haemorrhage and ventricular dilatation (PVH+VD, 17 VPT individuals with a history of uncomplicated periventricular haemorrhage (UPVH, 13 VPT individuals with no history of neonatal brain injury and 17 controls received an MRI scan whilst completing a verbal fluency task with two cognitive loads ('easy' and 'hard' letters. Two groups of VPT individuals (PVH+VD; n = 10, UPVH; n = 8 performed an n-back task with three cognitive loads (1-, 2-, 3-back. Results demonstrated that VPT individuals displayed hyperactivation in frontal, temporal, and parietal cortices and in caudate nucleus, insula and thalamus compared to controls, as demands of the verbal fluency task increased, regardless of type of neonatal brain injury. On the other hand, during the n-back task and as working memory load increased, the PVH+VD group showed less engagement of the frontal cortex than the UPVH group. In conclusion, this study suggests that the functional neuroanatomy of different executive-type processes is altered following VPT birth and that neural activation associated with specific aspects of executive function (i.e., working memory may be particularly sensitive to the extent of neonatal brain injury.

Low-Dose Sevoflurane Promotes Hippocampal Neurogenesis and Facilitates the Development of Dentate Gyrus-Dependent Learning in Neonatal Rats

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Chong Chen

2015-04-01

Full Text Available Huge body of evidences demonstrated that volatile anesthetics affect the hippocampal neurogenesis and neurocognitive functions, and most of them showed impairment at anesthetic dose. Here, we investigated the effect of low dose (1.8% sevoflurane on hippocampal neurogenesis and dentate gyrus-dependent learning. Neonatal rats at postnatal day 4 to 6 (P4–6 were treated with 1.8% sevoflurane for 6 hours. Neurogenesis was quantified by bromodeoxyuridine labeling and electrophysiology recording. Four and seven weeks after treatment, the Morris water maze and contextual-fear discrimination learning tests were performed to determine the influence on spatial learning and pattern separation. A 6-hour treatment with 1.8% sevoflurane promoted hippocampal neurogenesis and increased the survival of newborn cells and the proportion of immature granular cells in the dentate gyrus of neonatal rats. Sevoflurane-treated rats performed better during the training days of the Morris water maze test and in contextual-fear discrimination learning test. These results suggest that a subanesthetic dose of sevoflurane promotes hippocampal neurogenesis in neonatal rats and facilitates their performance in dentate gyrus-dependent learning tasks.

Liver antioxidant stores protect the brain from electromagnetic radiation (900 and 1800 MHz)-induced oxidative stress in rats during pregnancy and the development of offspring.

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Çetin, Hasan; Nazıroğlu, Mustafa; Çelik, Ömer; Yüksel, Murat; Pastacı, Nural; Özkaya, Mehmet Okan

2014-12-01

The present study determined the effects of mobile phone (900 and 1800 MHz)-induced electromagnetic radiation (EMR) exposure on oxidative stress in the brain and liver as well as the element levels in growing rats from pregnancy to 6 weeks of age. Thirty-two rats and their offspring were equally divided into three different groups: the control, 900 MHz, and 1800 MHz groups. The 900 MHz and 1800 MHz groups were exposed to EMR for 60 min/d during pregnancy and neonatal development. At the 4th, 5th, and 6th weeks of the experiment, brain samples were obtained. Brain and liver glutathione peroxidase activities, as well as liver vitamin A and β-carotene concentrations decreased in the EMR groups, although brain iron, vitamin A, and β-carotene concentrations increased in the EMR groups. In the 6th week, selenium concentrations in the brain decreased in the EMR groups. There were no statistically significant differences in glutathione, vitamin E, chromium, copper, magnesium, manganese, and zinc concentrations between the three groups. EMR-induced oxidative stress in the brain and liver was reduced during the development of offspring. Mobile phone-induced EMR could be considered as a cause of oxidative brain and liver injury in growing rats.

Neonatal brain injury and neuroanatomy of memory processing following very preterm birth in adulthood: an fMRI study.

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Anastasia K Kalpakidou

Full Text Available Altered functional neuroanatomy of high-order cognitive processing has been described in very preterm individuals (born before 33 weeks of gestation; VPT compared to controls in childhood and adolescence. However, VPT birth may be accompanied by different types of adverse neonatal events and associated brain injury, the severity of which may have differential effects on brain development and subsequent neurodevelopmental outcome. We conducted a functional magnetic resonance imaging (fMRI study to investigate how differing degrees of neonatal brain injury, detected by neonatal ultrasounds, affect the functional neuroanatomy of memory processing in VPT young adults. We used a verbal paired associates learning task, consisting of four encoding, four cued-recall and four baseline condition blocks. To further investigate whether differences in neural activation between the groups were modulated by structural brain changes, structural MRI data were also collected. We studied 12 VPT young adults with a history of periventricular haemorrhage with associated ventricular dilatation, 17 VPT individuals with a history of uncomplicated periventricular haemorrhage, 12 individuals with normal ultrasonographic findings, and 17 controls. Results of a linear trend analysis demonstrated that during completion of the paired associates learning task right frontal and right parietal brain activation decreased as the severity of neonatal brain injury increased. There were no statistically significant between-group differences in on-line task performance and participants' intelligence quotient (IQ at assessment. This pattern of differential activation across the groups was observed particularly in the right middle frontal gyrus during encoding and in the right posterior cingulate gyrus during recall. Structural MRI data analysis revealed that grey matter volume in the right superior temporal gyrus, right cerebellum, left middle temporal gyrus, right globus pallidus and

Neonatal overfeeding disrupts pituitary ghrelin signalling in female rats long-term; Implications for the stress response.

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Sominsky, Luba; Ziko, Ilvana; Spencer, Sarah J

2017-01-01

The hypothalamic-pituitary-adrenal (HPA) axis responses to psychological stress are exacerbated in adult female but not male rats made obese due to overfeeding in early life. Ghrelin, traditionally known for its role in energy homeostasis, has been recently recognised for its role in coordinating the HPA responses to stress, particularly by acting directly at the anterior pituitary where the growth hormone secretagogue receptor (GHSR), the receptor for acyl ghrelin, is abundantly expressed. We therefore hypothesised that neonatal overfeeding in female rats would compromise pituitary responsiveness to ghrelin, contributing to a hyperactive central stress responsiveness. Unlike in males where hypothalamic ghrelin signalling is compromised by neonatal overfeeding, there was no effect of early life diet on circulating ghrelin or hypothalamic ghrelin signalling in females, indicating hypothalamic feeding and metabolic ghrelin circuitry remains intact. However, neonatal overfeeding did lead to long-term alterations in the pituitary ghrelin system. The neonatally overfed females had increased neonatal and reduced adult expression of GHSR and ghrelin-O-acyl transferase (GOAT) in the pituitary as well as reduced pituitary responsiveness to exogenous acyl ghrelin-induced adrenocorticotropic hormone (ACTH) release in vitro. These data suggest that neonatal overfeeding dysregulates pituitary ghrelin signalling long-term in females, potentially accounting for the hyper-responsive HPA axis in these animals. These findings have implications for how females may respond to stress throughout life, suggesting the way ghrelin modifies the stress response at the level of the pituitary may be less efficient in the neonatally overfed.

Protective Effects of N-Acetyl-L-Cysteine in Human Oligodendrocyte Progenitor Cells and Restoration of Motor Function in Neonatal Rats with Hypoxic-Ischemic Encephalopathy

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Dongsun Park

2015-01-01

Full Text Available Objective. Since oligodendrocyte progenitor cells (OPCs are the target cells of neonatal hypoxic-ischemic encephalopathy (HIE, the present study was aimed at investigating the protective effects of N-acetyl-L-cysteine (NAC, a well-known antioxidant and precursor of glutathione, in OPCs as well as in neonatal rats. Methods. In in vitro study, protective effects of NAC on KCN cytotoxicity in F3.Olig2 OPCs were investigated via MTT assay and apoptotic signal analysis. In in vivo study, NAC was administered to rats with HIE induced by hypoxia-ischemia surgery at postnatal day 7, and their motor functions and white matter demyelination were analyzed. Results. NAC decreased KCN cytotoxicity in F3.Olig2 cells and especially suppressed apoptosis by regulating Bcl2 and p-ERK. Administration of NAC recovered motor functions such as the using ratio of forelimb contralateral to the injured brain, locomotor activity, and rotarod performance of neonatal HIE animals. It was also confirmed that NAC attenuated demyelination in the corpus callosum, a white matter region vulnerable to HIE. Conclusion. The results indicate that NAC exerts neuroprotective effects in vitro and in vivo by preserving OPCs, via regulation of antiapoptotic signaling, and that F3.Olig2 human OPCs could be a good tool for screening of candidates for demyelinating diseases.

Three-dimensional engineered heart tissue from neonatal rat cardiac myocytes.

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Zimmermann, W H; Fink, C; Kralisch, D; Remmers, U; Weil, J; Eschenhagen, T

2000-04-05

A technique is presented that allows neonatal rat cardiac myocytes to form spontaneously and coherently beating 3-dimensional engineered heart tissue (EHT) in vitro, either as a plane biconcaval matrix anchored at both sides on Velcro-coated silicone tubes or as a ring. Contractile activity was monitored in standard organ baths or continuously in a CO(2) incubator for up to 18 days (=26 days after casting). Long-term measurements showed an increase in force between days 8 and 18 after casting and stable forces thereafter. At day 10, the twitch amplitude (TA) of electrically paced EHTs (average length x width x thickness, 11 x 6 x 0.4 mm) was 0.51 mN at length of maximal force development (L(max)) and a maximally effective calcium concentration. EHTs showed typical features of neonatal rat heart: a positive force-length and a negative force-frequency relation, high sensitivity to calcium (EC(50) 0.24 mM), modest positive inotropic (increase in TA by 46%) and pronounced positive lusitropic effect of isoprenaline (decrease in twitch duration by 21%). Both effects of isoprenaline were sensitive to the muscarinic receptor agonist carbachol in a pertussis toxin-sensitive manner. Adenovirus-mediated gene transfer of beta-galactosidase into EHTs reached 100% efficiency. In summary, EHTs retain many of the physiological characteristics of rat cardiac tissue and allow efficient gene transfer with subsequent force measurement. Copyright 2000 John Wiley & Sons, Inc.

Development of antibodies against the rat brain somatostatin receptor.

Science.gov (United States)

Theveniau, M; Rens-Domiano, S; Law, S F; Rougon, G; Reisine, T

1992-05-15

Somatostatin (SRIF) is a neurotransmitter in the brain involved in the regulation of motor activity and cognition. It induces its physiological actions by interacting with receptors. We have developed antibodies against the receptor to investigate its structural properties. Rabbit polyclonal antibodies were generated against the rat brain SRIF receptor. These antibodies (F4) were able to immunoprecipitate solubilized SRIF receptors from rat brain and the cell line AtT-20. The specificity of the interaction of these antibodies with SRIF receptors was further demonstrated by immunoblotting. F4 detected SRIF receptors of 60 kDa from rat brain and adrenal cortex and the cell lines AtT-20, GH3, and NG-108, which express high densities of SRIF receptors. They did not detect immunoreactive material from rat liver or COS-1, HEPG, or CRL cells, which do not express functional SRIF receptors. In rat brain, 60-kDa immunoreactivity was detected by F4 in the hippocampus, cerebral cortex, and striatum, which have high densities of SRIF receptors. However, F4 did not interact with proteins from cerebellum and brain stem, which express few SRIF receptors. Immunoreactive material cannot be detected in rat pancreas or pituitary, which have been reported to express a 90-kDa SRIF receptor subtype. The selective detection of 60-kDa SRIF receptors by F4 indicates that the 60- and 90-kDa SRIF receptor subtypes are immunologically distinct. The availability of antibodies that selectively detect native and denatured brain SRIF receptors provides us with a feasible approach to clone the brain SRIF receptor gene(s).

Low body weight and cardiac tolerance to ischemia in neonatal rats

Czech Academy of Sciences Publication Activity Database

Chvojková, Zuzana; Ošťádalová, Ivana; Ošťádal, Bohuslav

2005-01-01

Roč. 54, č. 4 (2005), s. 357-362 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/00/1659; GA MŠk(CZ) LN00A069 Institutional research plan: CEZ:AV0Z5011922 Keywords : low body weight * cardiac tolerance to ischemia * neonatal rats Subject RIV: ED - Physiology Impact factor: 1.806, year: 2005

Brain dysfunctions in Wistar rats exposed to municipal landfill leachates

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Chibuisi G. Alimba

2015-12-01

Full Text Available Brain damage induced by Olusosun and Aba-Eku municipal landfill leachates was investigated in Wistar rats. Male rats were orally exposed to 1–25% concentrations of the leachates for 30 days. Catalase (CAT and superoxide dismutase (SOD activities, and malondialdehyde (MDA concentrations in the brain and serum of rats were evaluated; body and brain weight gain and histopathology were examined. There was significant (p < 0.05 decrease in body weight gain and SOD activity but increase in absolute and relative brain weight gain, MDA concentration and CAT activity in both brain and serum of treated rats. The biochemical parameters, which were more altered in the brain than serum, corroborated the neurologic lesions; neurodegeneration of purkinje cells with loss of dendrites, perineural vacuolations of the neuronal cytoplasm (spongiosis and neuronal necrosis in the brain. The concentrations of Cr, Cu, Pb, As, Cd, Mn, Ni, sulphates, ammonia, chloride and phosphate in the leachate samples were above standard permissible limits. The interactions of the neurotoxic constituents of the leachates induced the observed brain damage in the rats via oxidative damage. This suggests health risk in wildlife and human populations.

Lead poisoning and the blood-brain barrier

International Nuclear Information System (INIS)

Hertz, M.H.; Bolwig, T.G.; Grandjean, P.; Westergaard, E.

1981-01-01

Lead exposure may produce varying degrees of neuropsychiatric manifestations from discrete phenomena, quite often seen in children and as an occupational disease, to the rare fulminant lead encephalopathy. It was determined whether or not damage of the blood-brain barrier permeability in adult rats, as has been demonstr rated in neonatal animals exposed to lead, could also play a role. Massive lead exposure did not induce any change in the transfer (facilitated diffusion) of phenylalanine and tyrosine measured by means of the indicator dilution technique. Ultrastructural examination, after application of horseradish peroxidase, did not reveal any pahtological changes in the permeability to the tracer. It is concluded that in adult rats, in contrast to neonatal anmials, the observed pathological signs clearly seen in the chronically exposed animals must be ascribed to a noxious influence of lead on the extravascular side of the blood-brain barrier. (author)

Neuroprotection by selective neuronal deletion of Atg7 in neonatal brain injury

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Xie, Cuicui; Ginet, Vanessa; Sun, Yanyan; Koike, Masato; Zhou, Kai; Li, Tao; Li, Hongfu; Li, Qian; Wang, Xiaoyang; Uchiyama, Yasuo; Truttmann, Anita C.; Kroemer, Guido; Puyal, Julien; Blomgren, Klas; Zhu, Changlian

2016-01-01

ABSTRACT Perinatal asphyxia induces neuronal cell death and brain injury, and is often associated with irreversible neurological deficits in children. There is an urgent need to elucidate the neuronal death mechanisms occurring after neonatal hypoxia-ischemia (HI). We here investigated the selective neuronal deletion of the Atg7 (autophagy related 7) gene on neuronal cell death and brain injury in a mouse model of severe neonatal hypoxia-ischemia. Neuronal deletion of Atg7 prevented HI-induced autophagy, resulted in 42% decrease of tissue loss compared to wild-type mice after the insult, and reduced cell death in multiple brain regions, including apoptosis, as shown by decreased caspase-dependent and -independent cell death. Moreover, we investigated the lentiform nucleus of human newborns who died after severe perinatal asphyxia and found increased neuronal autophagy after severe hypoxic-ischemic encephalopathy compared to control uninjured brains, as indicated by the numbers of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3)-, LAMP1 (lysosomal-associated membrane protein 1)-, and CTSD (cathepsin D)-positive cells. These findings reveal that selective neuronal deletion of Atg7 is strongly protective against neuronal death and overall brain injury occurring after HI and suggest that inhibition of HI-enhanced autophagy should be considered as a potential therapeutic target for the treatment of human newborns developing severe hypoxic-ischemic encephalopathy. PMID:26727396

The common antitussive agent dextromethorphan protects against hyperoxia-induced cell death in established in vivo and in vitro models of neonatal brain injury.

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Posod, A; Pinzer, K; Urbanek, M; Wegleiter, K; Keller, M; Kiechl-Kohlendorfer, U; Griesmaier, E

2014-08-22

Preterm infants are prematurely subjected to relatively high oxygen concentrations, even when supplemental oxygen is not administered. There is increasing evidence to show that an excess of oxygen is toxic to the developing brain. Dextromethorphan (DM), a frequently used antitussive agent with pleiotropic mechanisms of action, has been shown to be neuroprotective in various models of central nervous system pathology. Due to its numerous beneficial properties, it might also be able to counteract detrimental effects of a neonatal oxygen insult. The aim of the current study was to evaluate its therapeutic potential in established cell culture and rodent models of hyperoxia-induced neonatal brain injury. For in vitro studies pre- and immature oligodendroglial (OLN-93) cells were subjected to hyperoxic conditions for 48 h after pre-treatment with increasing doses of DM. For in vivo studies 6-day-old Wistar rat pups received a single intraperitoneal injection of DM in two different dosages prior to being exposed to hyperoxia for 24h. Cell viability and caspase-3 activation were assessed as outcome parameters at the end of exposure. DM significantly increased cell viability in immature oligodendroglial cells subjected to hyperoxia. In pre-oligodendroglial cells cell viability was not significantly affected by DM treatment. In vivo caspase-3 activation induced by hyperoxic exposure was significantly lower after administration of DM in gray and white matter areas. In control animals kept under normoxic conditions DM did not significantly influence caspase-3-dependent apoptosis. The present results indicate that DM is a promising and safe treatment strategy for neonatal hyperoxia-induced brain injury that merits further investigation. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Correlation between subacute sensorimotor deficits and brain water content after surgical brain injury in rats

OpenAIRE

McBride, Devin W.; Wang, Yuechun; Sherchan, Prativa; Tang, Jiping; Zhang, John H.

2015-01-01

Brain edema is a major contributor to poor outcome and reduced quality of life after surgical brain injury (SBI). Although SBI pathophysiology is well-known, the correlation between cerebral edema and neurological deficits has not been thoroughly examined in the rat model of SBI. Thus, the purpose of this study was to determine the correlation between brain edema and deficits in standard sensorimotor neurobehavior tests for rats subjected to SBI. Sixty male Sprague-Dawley rats were subjected ...

Neonatal Brain Abnormalities and Memory and Learning Outcomes at 7 Years in Children Born Very Preterm

Science.gov (United States)

Omizzolo, Cristina; Scratch, Shannon E; Stargatt, Robyn; Kidokoro, Hiroyuki; Thompson, Deanne K; Lee, Katherine J; Cheong, Jeanie; Neil, Jeffrey; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

2014-01-01

Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term born controls. Neonatal brain abnormalities, and in particular deep grey matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children, especially global, white-matter, grey-matter and cerebellar abnormalities. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function. PMID:23805915

Neonatal maternal separation up-regulates protein signalling for cell survival in rat hypothalamus.

Science.gov (United States)

Irles, Claudine; Nava-Kopp, Alicia T; Morán, Julio; Zhang, Limei

2014-05-01

We have previously reported that in response to early life stress, such as maternal hyperthyroidism and maternal separation (MS), the rat hypothalamic vasopressinergic system becomes up-regulated, showing enlarged nuclear volume and cell number, with stress hyperresponsivity and high anxiety during adulthood. The detailed signaling pathways involving cell death/survival, modified by adverse experiences in this developmental window remains unknown. Here, we report the effects of MS on cellular density and time-dependent fluctuations of the expression of pro- and anti-apoptotic factors during the development of the hypothalamus. Neonatal male rats were exposed to 3 h-daily MS from postnatal days 2 to 15 (PND 2-15). Cellular density was assessed in the hypothalamus at PND 21 using methylene blue staining, and neuronal nuclear specific protein and glial fibrillary acidic protein immunostaining at PND 36. Expression of factors related to apoptosis and cell survival in the hypothalamus was examined at PND 1, 3, 6, 9, 12, 15, 20 and 43 by Western blot. Rats subjected to MS exhibited greater cell-density and increased neuronal density in all hypothalamic regions assessed. The time course of protein expression in the postnatal brain showed: (1) decreased expression of active caspase 3; (2) increased Bcl-2/Bax ratio; (3) increased activation of ERK1/2, Akt and inactivation of Bad; PND 15 and PND 20 were the most prominent time-points. These data indicate that MS can induce hypothalamic structural reorganization by promoting survival, suppressing cell death pathways, increasing cellular density which may alter the contribution of these modified regions to homeostasis.

Low-dose sevoflurane promotes hippocampal neurogenesis and facilitates the development of dentate gyrus-dependent learning in neonatal rats.

Science.gov (United States)

Chen, Chong; Shen, Feng-Yan; Zhao, Xuan; Zhou, Tao; Xu, Dao-Jie; Wang, Zhi-Ru; Wang, Ying-Wei

2015-01-01

Huge body of evidences demonstrated that volatile anesthetics affect the hippocampal neurogenesis and neurocognitive functions, and most of them showed impairment at anesthetic dose. Here, we investigated the effect of low dose (1.8%) sevoflurane on hippocampal neurogenesis and dentate gyrus-dependent learning. Neonatal rats at postnatal day 4 to 6 (P4-6) were treated with 1.8% sevoflurane for 6 hours. Neurogenesis was quantified by bromodeoxyuridine labeling and electrophysiology recording. Four and seven weeks after treatment, the Morris water maze and contextual-fear discrimination learning tests were performed to determine the influence on spatial learning and pattern separation. A 6-hour treatment with 1.8% sevoflurane promoted hippocampal neurogenesis and increased the survival of newborn cells and the proportion of immature granular cells in the dentate gyrus of neonatal rats. Sevoflurane-treated rats performed better during the training days of the Morris water maze test and in contextual-fear discrimination learning test. These results suggest that a subanesthetic dose of sevoflurane promotes hippocampal neurogenesis in neonatal rats and facilitates their performance in dentate gyrus-dependent learning tasks. © The Author(s) 2015.

Effects of benzo(a)pyrene exposure on the ATPase activity and calcium concentration in the hippocampus of neonatal rats.

Science.gov (United States)

Yang, Kai; Chen, Chengzhi; Cheng, Shuqun; Cao, Xianqing; Tu, Baijie

2017-03-30

To investigate whether postnatal benzo(a)pyrene (B(a)P) exposure caused the impairments on the process of neurodevelopment and the alteration in the calcium medium in the neonatal rats. Eighty neonatal Sprague Dawley (SD) rats were randomly divided into 5 groups (untreated control group, vehicle group, 0.02 mg/kg, 0.2 mg/kg and 2 mg/kg B(a)P-exposed group). Rats were treated with B(a)P by the intragastric administration from postnatal day (PND) 4 to 25. Morris water maze (MWM) was employed to observe the spatial memory of rats. The activity of calcium adenosine triphosphatase (Ca2+-ATPase), sodium-potassium adenosine triphosphatase (Na+-K+-ATPase) and calcium-magnesium adenosine triphosphatase (Ca2+-Mg2+-ATPase) in the hippocampus were detected by commercial kits. Fura-2 pentakis(acetoxymethyl) (Fura-2/AM) probe and reactive oxygen species (ROS) reagent kit were used for measuring the concentration of Ca2+ and ROS in the hippocampus synapse, respectively. Rats exposed to B(a)P resulted in the deficits in the spatial memory manifested by the increased escape latency and decreased number of crossing platform and time spent in target quadrant in comparison with the control groups. Benzo(a)pyrene exposure caused the significant decrease in the ATPase activity in the hippocampus and caused Ca2+ overload in the synaptic, besides, the ROS concentration increased significantly which may further induce neurobehavioral impairment of the neonatal rats. Our findings suggest that postnatal B(a)P exposure may cause the neurobehavioral impairments in the neonatal rats, which were mediated by the decreased ATPase activity and elevated Ca2+ concentration. Int J Occup Med Environ Health 2017;30(2):203-211. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Extreme hypoxia tolerance of naked mole-rat brain.

Science.gov (United States)

Larson, John; Park, Thomas J

2009-12-09

Mammalian brains have extremely high levels of aerobic metabolism and typically suffer irreversible damage after brief periods of oxygen deprivation such as occur during stroke or cardiac arrest. Here we report that brain tissue from naked mole-rats, rodents that live in a chronically low-oxygen environment, is remarkably resistant to hypoxia: naked mole-rat neurons maintain synaptic transmission much longer than mouse neurons and can recover from periods of anoxia exceeding 30 min. We suggest that brain tolerance to hypoxia may result from slowed or arrested brain development in these extremely long-lived animals.

In vitro comparison of rat and chicken brain neurotoxic esterase

International Nuclear Information System (INIS)

Novak, R.; Padilla, S.

1986-01-01

A systematic comparison was undertaken to characterize neurotoxic esterase (NTE) from rat and chicken brain in terms of inhibitor sensitivities, pH optima, and molecular weights. Paraoxon titration of phenyl valerate (PV)-hydrolyzing carboxylesterases showed that rat esterases were more sensitive than chicken to paraoxon inhibition at concentrations less than or equal to microM and superimposable with chicken esterases at concentrations of 2.5-1000 microM. Mipafox titration of the paraoxon-resistant esterases at a fixed paraoxon concentration of 100 microM (mipafox concentration: 0-1000 microM) resulted in a mipafox I50 of 7.3 microM for chicken brain NTE and 11.6 microM for rat brain NTE. NTE (i.e., paraoxon-resistant, mipafox-sensitive esterase activity) comprised 80% of chicken and 60% of rat brain paraoxon-resistant activity with the specific activity of chicken brain NTE approximately twice that of rat brain NTE. The pH maxima for NTE from both species was similar showing broad, slightly alkaline optima from pH 7.9 to 8.6. [ 3 H]Diisopropyl phosphorofluoridate (DFP)-labeled NTE from the brains of both species had an apparent mol wt of 160,000 measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis. In conclusion, NTE from both species was very similar, with the mipafox I50 for rat NTE within the range of reported values for chicken and human NTE, and the inhibitor parameters of the chicken NTE assay were applicable for the rat NTE assay

Disruption of the blood-brain interface in neonatal rat neocortex induces a transient expression of metallothionein in reactive astrocytes

DEFF Research Database (Denmark)

Penkowa, M; Moos, T

1995-01-01

rats were subjected to a localized freeze lesion of the neocortex of the right temporal cortex. This lesion results in a disrupted blood-brain interface, leading to extravasation of plasma proteins. From 16 h, reactive astrocytosis, defined as an increase in the number and size of cells expressing GFAP...

An automatic rat brain extraction method based on a deformable surface model.

Science.gov (United States)

Li, Jiehua; Liu, Xiaofeng; Zhuo, Jiachen; Gullapalli, Rao P; Zara, Jason M

2013-08-15

The extraction of the brain from the skull in medical images is a necessary first step before image registration or segmentation. While pre-clinical MR imaging studies on small animals, such as rats, are increasing, fully automatic imaging processing techniques specific to small animal studies remain lacking. In this paper, we present an automatic rat brain extraction method, the Rat Brain Deformable model method (RBD), which adapts the popular human brain extraction tool (BET) through the incorporation of information on the brain geometry and MR image characteristics of the rat brain. The robustness of the method was demonstrated on T2-weighted MR images of 64 rats and compared with other brain extraction methods (BET, PCNN, PCNN-3D). The results demonstrate that RBD reliably extracts the rat brain with high accuracy (>92% volume overlap) and is robust against signal inhomogeneity in the images. Copyright © 2013 Elsevier B.V. All rights reserved.

Neonatal domoic acid decreases in vivo binding of [11C]yohimbine to α2 adrenoceptors in adult rat brain

DEFF Research Database (Denmark)

Thomsen, Majken; Lillethorup, Thea Pinholt; Jakobsen, Steen

-quantitative analysis. MicroPET images were analyzed using PMOD software and registered to an average Sprague-Dawley rat MRI brain atlas to acquire data in limbic and cortical regions of interest. Results: In behavioural testing DOM60, and to a lesser extent DOM20 rats, spent more time in the periphery during the open......-Dawley rats (n=6-7 per group) were injected (s.c.) daily from postnatal day 8-14 with saline or one of two low sub-convulsive doses, 20µg/kg [DOM20] or 60µg/kg [DOM60] of DOM, an AMPA/kainate receptor agonist. The behaviour of the rats was observed in an open field test, a social interaction test...... and the forced swim test at day 50, 75 and 98, respectively. At ~120 days of age 3-4 rats per group were injected with [11C]yohimbine, an α2 adrenergic receptor antagonist, and scanned in a Mediso micro positron emission tomography (PET) scanner, to measure α2 adrenoceptor binding. The volume of distribution (VT...

Hypoglycemia is associated with increased risk for brain injury and adverse neurodevelopmental outcome in neonates at risk for encephalopathy.

Science.gov (United States)

Tam, Emily W Y; Haeusslein, Laurel A; Bonifacio, Sonia L; Glass, Hannah C; Rogers, Elizabeth E; Jeremy, Rita J; Barkovich, A James; Ferriero, Donna M

2012-07-01

To investigate the contribution of hypoglycemia in the first 24 hours after birth to brain injury in term newborns at risk for neonatal encephalopathy. A prospective cohort of 94 term neonates born between 1994 and 2010 with early postnatal brain magnetic resonance imaging studies were analyzed for regions of brain injury. Neurodevelopmental outcome was assessed at 1 year of age. Hypoglycemia (glucose encephalopathy with increased corticospinal tract injury and adverse motor and cognitive outcomes. Copyright © 2012 Mosby, Inc. All rights reserved.

Dopaminergic modulation of striatal acetylcholine release in rats depleted of dopamine as neonates.

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Johnson, B J; Bruno, J P

1995-02-01

A repeated sessions, in vivo microdialysis design was used to determine the D1- and D2-like receptor modulation of striatal ACh efflux in intact adult rats and those depleted of DA on postnatal Day 3. Systemic administration of the D1-like agonist SKF 38393 (1.0 or 10.0 mg/kg, or the D2-like antagonist clebopride (1.0 or 10.0 mg/kg) increased ACh efflux in both controls and DA-depleted animals. Systemic administration of the D1-like antagonist SCH 23390 (0.05 or 0.2 mg/kg) or D2-like agonist quinpirole (0.5 or 1.0 mg/kg) decreased ACh efflux in both groups of animals. DA-depleted animals exhibited a larger response than did controls to the lower doses of these drugs. Intrastriatal administration of clebopride (10 microM) increased ACh efflux in DA-depleted animals. Finally, basal and clebopride-stimulated ACh efflux were unaffected by the repeated microdialysis sessions. These data demonstrate that the reciprocal modulation of striatal ACh efflux, seen in controls and in rats depleted of DA as adults, is also present in adults depleted of DA as neonates. Because the roles of D1- and D2-receptors in the expression of motor behavior differ between rats depleted of DA as adults vs as neonates, these data suggest that alterations in the dopaminergic modulation of striatal ACh release do not underlie the sparing from motoric deficits seen in animals depleted of DA as neonates.

KCNQ channels are involved in the regulatory volume decrease response in primary neonatal rat cardiomyocytes

DEFF Research Database (Denmark)

Calloe, Kirstine; Nielsen, Morten Schak; Grunnet, Morten

2007-01-01

of neonatal rat cardiomyocytes was studied in intact single cells attached to coverslips, i.e. with an intact cytoskeleton. The potential contribution of KCNQ (Kv7) channels to the RVD response and the possible involvement of the F-actin cytoskeleton were investigated. The rate of RVD was significantly...... changes the structure of the F-actin cytoskeleton, leading to a more rounded cell shape, less pronounced F-actin stress fibers and patches of actin. In the presence of cytochalasin D (1 microM), a potent inhibitor of actin polymerization, the RVD response was strongly reduced, confirming a possible role...... for an intact F-actin cytoskeleton in linking cell swelling to activation of ion transport in neonatal rat cardiomyocytes. Udgivelsesdato: 2007-Jun...

Neonicotinoid Insecticides Alter the Gene Expression Profile of Neuron-Enriched Cultures from Neonatal Rat Cerebellum

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Junko Kimura-Kuroda

2016-10-01

Full Text Available Neonicotinoids are considered safe because of their low affinities to mammalian nicotinic acetylcholine receptors (nAChRs relative to insect nAChRs. However, because of importance of nAChRs in mammalian brain development, there remains a need to establish the safety of chronic neonicotinoid exposures with regards to children’s health. Here we examined the effects of longterm (14 days and low dose (1 μM exposure of neuron-enriched cultures from neonatal rat cerebellum to nicotine and two neonicotinoids: acetamiprid and imidacloprid. Immunocytochemistry revealed no differences in the number or morphology of immature neurons or glial cells in any group versus untreated control cultures. However, a slight disturbance in Purkinje cell dendritic arborization was observed in the exposed cultures. Next we performed transcriptome analysis on total RNAs using microarrays, and identified significant differential expression (p < 0.05, q < 0.05, ≥1.5 fold between control cultures versus nicotine-, acetamiprid-, or imidacloprid-exposed cultures in 34, 48, and 67 genes, respectively. Common to all exposed groups were nine genes essential for neurodevelopment, suggesting that chronic neonicotinoid exposure alters the transcriptome of the developing mammalian brain in a similar way to nicotine exposure. Our results highlight the need for further careful investigations into the effects of neonicotinoids in the developing mammalian brain.

Neuropeptide Y receptors in rat brain: autoradiographic localization

International Nuclear Information System (INIS)

Martel, J.C.; St-Pierre, S.; Quirion, R.

1986-01-01

Neuropeptide Y (NPY) receptor binding sites have been characterized in rat brain using both membrane preparations and receptor autoradiography. Radiolabelled NPY binds with high affinity and specificity to an apparent single class of sites in rat brain membrane preparations. The ligand selectivity pattern reveals strong similarities between central and peripheral NPY receptors. NPY receptors are discretely distributed in rat brain with high densities found in the olfactory bulb, superficial layers of the cortex, ventral hippocampus, lateral septum, various thalamic nuclei and area postrema. The presence of high densities of NPY and NPY receptors in such areas suggests that NPY could serve important functions as a major neurotransmitter/neuromodulator in the central nervous system

Evidence that the periaqueductal gray matter mediates the facilitation of panic-like reactions in neonatally-isolated adult rats.

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Jeyce Willig Quintino-dos-Santos

Full Text Available Plenty of evidence suggests that childhood separation anxiety (CSA predisposes the subject to adult-onset panic disorder (PD. As well, panic is frequently comorbid with both anxiety and depression. The brain mechanisms whereby CSA predisposes to PD are but completely unknown in spite of the increasing evidence that panic attacks are mediated at midbrain's dorsal periaqueductal gray matter (DPAG. Accordingly, here we examined whether the neonatal social isolation (NSI, a model of CSA, facilitates panic-like behaviors produced by electrical stimulations of DPAG of rats as adults. Eventual changes in anxiety and depression were also assessed in the elevated plus-maze (EPM and forced-swimming test (FST respectively. Male pups were subjected to 3-h daily isolations from post-natal day 2 (PN2 until weaning (PN21 allotting half of litters in individual boxes inside a sound-attenuated chamber (NSI, n = 26 whilst siblings (sham-isolated rats, SHAM, n = 27 and dam were moved to another box in a separate room. Non-handled controls (CTRL, n = 18 remained undisturbed with dams until weaning. As adults, rats were implanted with electrodes into the DPAG (PN60 and subjected to sessions of intracranial stimulation (PN65, EPM (PN66 and FST (PN67-PN68. Groups were compared by Fisher's exact test (stimulation sites, likelihood ratio chi-square tests (stimulus-response threshold curves and Bonferroni's post hoc t-tests (EPM and FST, for P<0.05. Notably, DPAG-evoked panic-like responses of immobility, exophthalmus, trotting, galloping and jumping were markedly facilitated in NSI rats relative to both SHAM and CTRL groups. Conversely, anxiety and depression scores either did not change or were even reduced in neonatally-handled groups relative to CTRL, respectively. Data are the first behavioral evidence in animals that early-life separation stress produces the selective facilitation of panic-like behaviors in adulthood. Most importantly, results implicate

Tumor necrosis factor-alpha during neonatal brain development affects anxiety- and depression-related behaviors in adult male and female mice.

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Babri, Shirin; Doosti, Mohammad-Hossein; Salari, Ali-Akbar

2014-03-15

A nascent literature suggests that neonatal infection is a risk factor for the development of brain, behavior and hypothalamic-pituitary-adrenal axis which can affect anxiety- and depression-related behaviors in later life. It has been documented that neonatal infection raises the concentrations of tumor necrosis factor-alpha (TNF-α) in neonate rodents and such infections may result in neonatal brain injury, at least in part, through pro-inflammatory cytokines. In addition, previous studies have shown that TNF-α is involved in cellular differentiation, neurogenesis and programmed cell death during the development of the central nervous system. We investigated for the first time whether neonatal exposure to TNF-α can affect body weight, stress-induced corticosterone (COR), anxiety- and depression-related behaviors in adult mice. In the present study, neonatal mice were treated to recombinant mouse TNF-α (0.2, 0.4, 0.7 and 1 μg/kg) or saline on postnatal days 3 and 5, then adult male and female mice were exposed to different behavioral tests. The results indicated that neonatal TNF-α treatment reduced body weight in neonatal period in both sexes. In addition, this study presents findings indicating that high doses of TNF- increase stress-induced COR levels, anxiety- and depression-related behaviors in adult males, but increase levels of anxiety without significantly influencing depression in adult female mice [corrected]. Our findings suggest that TNF-α exposure during neonatal period can alter brain and behavior development in a dose and sex-dependent manner in mice. Copyright © 2014 Elsevier B.V. All rights reserved.

Functional Magnetic Resonance Study of Non-conventional Morphological Brains: malnourished rats

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Martin R.

2015-08-01

Full Text Available Malnutrition during brain development can cause serious problems that can be irreversible. Dysfunctional patterns of brain activity can be detected with functional MRI. We used BOLD functional Magnetic Resonance Imaging (fMRI to investigate region differences of brain activity between control and malnourished rats. The food-competition method was applied to a rat model to induce malnutrition during lactation. A 7T magnet was used to detect changes of the BOLD signal associated with changes in brain activity caused by the trigeminal nerve stimulation in malnourished and control rats. Major neuronal activation was observed in malnourished rats in several brain regions, including cerebellum, somatosensory cortex, hippocampus, and hypothalamus. Statistical analysis of the BOLD signals from various brain areas revealed significant differences in somatosensory cortex between the control and experimental groups, as well as a significant difference between the cerebellum and other structures in the experimental group. This study, particularly in malnourished rats, demonstrates increased BOLD activation in the cerebellum.

Expression of aquaporin 9 in rat liver and efferent ducts of the male reproductive system after neonatal diethylstilbestrol exposure

DEFF Research Database (Denmark)

Wellejus, Anja; Jensen, Henrik E; Loft, Steffen

2008-01-01

Aquaporins (AQP) have important solute transport functions in many tissues including the epididymal efferent ducts (ED) and in the liver. We investigated the effect of neonatal exposure to diethylstilbestrol (DES) on AQP9 expressions in the ED and in the liver of rats. DES was administered from d...... to the epithelial cells of the ED. In conclusion, neonatal DES exposure appears to upregulate AQP9 channels in the ED in male rats, whereas a downregulation in the hepatic expression was observed, particularly in the periacinous area....

CNS development under altered gravity: cerebellar glial and neuronal protein expression in rat neonates exposed to hypergravity

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Nguon, K.; Li, G.-H.; Sajdel-Sulkowska, E. M.

2004-01-01

The future of space exploration depends on a solid understanding of the developmental process under microgravity, specifically in relation to the central nervous system (CNS). We have previously employed a hypergravity paradigm to assess the impact of altered gravity on the developing rat cerebellum [Exp. Biol. Med. 226 (2000) 790]. The present study addresses the molecular mechanisms involved in the cerebellar response to hypergravity. Specifically, the study focuses on the expression of selected glial and neuronal cerebellar proteins in rat neonates exposed to hypergravity (1.5 G) from embryonic day (E)11 to postnatal day (P)6 or P9 (the time of maximal cerebellar changes) comparing them against their expression in rat neonates developing under normal gravity. Proteins were analyzed by quantitative Western blots of cerebellar homogenates; RNA analysis was performed in the same samples using quantitative PCR. Densitometric analysis of Western blots suggested a reduction in glial (glial acidic protein, GFAP) and neuronal (neuronal cell adhesion moiecule, NCAM-L1, synaptophysin) proteins, but the changes in individual cerebellar proteins in hypergravity-exposed neonates appeared both age- and gender-specific. RNA analysis suggested a reduction in GFAP and synaptophysin mRNAs on P6. These data suggest that exposure to hypergravity may interfere with the expression of selected cerebellar proteins. These changes in protein expression may be involved in mediating the effect of hypergravity on the developing rat cerebellum.

On the edge of language acquisition: inherent constraints on encoding multisyllabic sequences in the neonate brain.

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Ferry, Alissa L; Fló, Ana; Brusini, Perrine; Cattarossi, Luigi; Macagno, Francesco; Nespor, Marina; Mehler, Jacques

2016-05-01

To understand language, humans must encode information from rapid, sequential streams of syllables - tracking their order and organizing them into words, phrases, and sentences. We used Near-Infrared Spectroscopy (NIRS) to determine whether human neonates are born with the capacity to track the positions of syllables in multisyllabic sequences. After familiarization with a six-syllable sequence, the neonate brain responded to the change (as shown by an increase in oxy-hemoglobin) when the two edge syllables switched positions but not when two middle syllables switched positions (Experiment 1), indicating that they encoded the syllables at the edges of sequences better than those in the middle. Moreover, when a 25 ms pause was inserted between the middle syllables as a segmentation cue, neonates' brains were sensitive to the change (Experiment 2), indicating that subtle cues in speech can signal a boundary, with enhanced encoding of the syllables located at the edges of that boundary. These findings suggest that neonates' brains can encode information from multisyllabic sequences and that this encoding is constrained. Moreover, subtle segmentation cues in a sequence of syllables provide a mechanism with which to accurately encode positional information from longer sequences. Tracking the order of syllables is necessary to understand language and our results suggest that the foundations for this encoding are present at birth. © 2015 John Wiley & Sons Ltd.

A-to-I RNA editing in the rat brain is age-dependent, region-specific and sensitive to environmental stress across generations.

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Zaidan, Hiba; Ramaswami, Gokul; Golumbic, Yaela N; Sher, Noa; Malik, Assaf; Barak, Michal; Galiani, Dalia; Dekel, Nava; Li, Jin B; Gaisler-Salomon, Inna

2018-01-08

Adenosine-to-inosine (A-to-I) RNA editing is an epigenetic modification catalyzed by adenosine deaminases acting on RNA (ADARs), and is especially prevalent in the brain. We used the highly accurate microfluidics-based multiplex PCR sequencing (mmPCR-seq) technique to assess the effects of development and environmental stress on A-to-I editing at 146 pre-selected, conserved sites in the rat prefrontal cortex and amygdala. Furthermore, we asked whether changes in editing can be observed in offspring of stress-exposed rats. In parallel, we assessed changes in ADARs expression levels. In agreement with previous studies, we found editing to be generally higher in adult compared to neonatal rat brain. At birth, editing was generally lower in prefrontal cortex than in amygdala. Stress affected editing at the serotonin receptor 2c (Htr2c), and editing at this site was significantly altered in offspring of rats exposed to prereproductive stress across two generations. Stress-induced changes in Htr2c editing measured with mmPCR-seq were comparable to changes measured with Sanger and Illumina sequencing. Developmental and stress-induced changes in Adar and Adarb1 mRNA expression were observed but did not correlate with editing changes. Our findings indicate that mmPCR-seq can accurately detect A-to-I RNA editing in rat brain samples, and confirm previous accounts of a developmental increase in RNA editing rates. Our findings also point to stress in adolescence as an environmental factor that alters RNA editing patterns several generations forward, joining a growing body of literature describing the transgenerational effects of stress.

Gastrointestinal absorption and retention of plutonium-238 in neonatal rats and swine

International Nuclear Information System (INIS)

Sullivan, M.F.

1978-01-01

Neonatal rats gavaged with 237 Pu or 238 Pu retained a substantial quantity in gut mucosa for a week but absorbed only 2.9% of the 237 Pu. After 140 days the amount retained fell to half that initially deposited. Newborn swine also retained large amounts in the gut and absorbed about 40% of the dose

Pivotal Role of Brain-Derived Neurotrophic Factor Secreted by Mesenchymal Stem Cells in Severe Intraventricular Hemorrhage in Newborn Rats.

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Ahn, So Yoon; Chang, Yun Sil; Sung, Dong Kyung; Sung, Se In; Ahn, Jee-Yin; Park, Won Soon

2017-01-24

Mesenchymal stem cell (MSC) transplantation protects against neonatal severe intraventricular hemorrhage (IVH)-induced brain injury by a paracrine rather than regenerative mechanism; however, the paracrine factors involved and their roles have not yet been delineated. This study aimed to identify the paracrine mediator(s) and to determine their role in mediating the therapeutic effects of MSCs in severe IVH. We first identified significant upregulation of brain-derived neurotrophic factor (BDNF) in MSCs compared with fibroblasts, in both DNA and antibody microarrays, after thrombin exposure. We then knocked down BDNF in MSCs by transfection with small interfering (si)RNA specific for human BDNF. The therapeutic effects of MSCs with or without BDNF knockdown were evaluated in vitro in rat neuronal cells challenged with thrombin, and in vivo in newborn Sprague-Dawley rats by injecting 200 μl of blood on postnatal day 4 (P4), and transplanting MSCs (1 × 105 cells) intraventricularly on P6. siRNA-induced BDNF knockdown abolished the in vitro benefits of MSCs on thrombin-induced neuronal cell death. BDNF knockdown also abolished the in vivo protective effects against severe IVH-induced brain injuries such as the attenuation of posthemorrhagic hydrocephalus, impaired behavioral test performance, increased astrogliosis, increased number of TUNEL cells, ED-1+ cells, and inflammatory cytokines, and reduced myelin basic protein expression. Our data indicate that BDNF secreted by transplanted MSCs is one of the critical paracrine factors that play a seminal role in attenuating severe IVH-induced brain injuries in newborn rats.

Parcellation of the Healthy Neonatal Brain into 107 Regions Using Atlas Propagation through Intermediate Time Points in Childhood.

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Blesa, Manuel; Serag, Ahmed; Wilkinson, Alastair G; Anblagan, Devasuda; Telford, Emma J; Pataky, Rozalia; Sparrow, Sarah A; Macnaught, Gillian; Semple, Scott I; Bastin, Mark E; Boardman, James P

2016-01-01

Neuroimage analysis pipelines rely on parcellated atlases generated from healthy individuals to provide anatomic context to structural and diffusion MRI data. Atlases constructed using adult data introduce bias into studies of early brain development. We aimed to create a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired soon after birth from 33 typically developing neonates born at term (mean postmenstrual age at birth 39(+5) weeks, range 37(+2)-41(+6)). An adult brain atlas (SRI24/TZO) was propagated to the neonatal data using temporal registration via childhood templates with dense temporal samples (NIH Pediatric Database), with the final atlas (Edinburgh Neonatal Atlas, ENA33) constructed using the Symmetric Group Normalization (SyGN) method. After this step, the computed final transformations were applied to T2-weighted data, and fractional anisotropy, mean diffusivity, and tissue segmentations to provide a multi-modal atlas with 107 anatomical regions; a symmetric version was also created to facilitate studies of laterality. Volumes of each region of interest were measured to provide reference data from normal subjects. Because this atlas is generated from step-wise propagation of adult labels through intermediate time points in childhood, it may serve as a useful starting point for modeling brain growth during development.

Parcellation of the healthy neonatal brain into 107 regions using atlas propagation through intermediate time points in childhood

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Manuel eBlesa Cabez

2016-05-01

Full Text Available Neuroimage analysis pipelines rely on parcellated atlases generated from healthy individuals to provide anatomic context to structural and diffusion MRI data. Atlases constructed using adult data introduce bias into studies of early brain development. We aimed to create a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired soon after birth from 33 typically developing neonates born at term (mean postmenstrual age at birth 39+5 weeks, range 37+2-41+6. An adult brain atlas (SRI24/TZO was propagated to the neonatal data using temporal registration via childhood templates with dense temporal samples (NIH Pediatric Database, with the final atlas (Edinburgh Neonatal Atlas, ENA33 constructed using the Symmetric Group Normalization method. After this step, the computed final transformations were applied to T2-weighted data, and fractional anisotropy, mean diffusivity, and tissue segmentations to provide a multi-modal atlas with 107 anatomical regions; a symmetric version was also created to facilitate studies of laterality. Volumes of each region of interest were measured to provide reference data from normal subjects. Because this atlas is generated from step-wise propagation of adult labels through intermediate time points in childhood, it may serve as a useful starting point for modelling brain growth during development.

Neurological assessments after treatment with the antimalarial β-arteether in neonatal and adult rats.

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Erickson, R I; Defensor, E B; Fairchild, D G; Mirsalis, J C; Steinmetz, K L

2011-08-01

The World Health Organization currently recommends combinatorial treatment including artemisinins as first-line therapy against drug-resistant Plasmodium falciparum malaria. Although highly efficacious, artemisinin and its derivatives, including β-arteether (βAE), are associated with ototoxicity, tremors, and other autonomic and motor impairments in the clinic. Similar neurological symptoms, as well as brainstem lesions, have been observed in adult laboratory species (mice, rats, dogs, and non human primates) following acute treatment with βAE; however, few long-term, nonclinical studies have been conducted. Furthermore, the majority of deaths attributed to malarial infection occur in children under age five, yet no laboratory studies have been initiated in neonatal or juvenile animals. In the current study, neonatal 7-day-old rats were administered intramuscular doses of 1-90 mg/kg βAE in sesame oil for up to eight treatment cycles (one cycle=7 days treatment+7 days without treatment). Neonates were tested for changes in sensorimotor function, and the same animals were tested as adults in the Functional Observational Battery, for motor activity, and in the 8-arm radial maze. Pups receiving a single cycle of 60 or 90 mg/kg died within a week of treatment but had few behavioral changes and no brainstem pathology. In the long-term study, behavioral and motor changes and brainstem lesions were observed in a dose- and time-related manner. Rats given repeated cycles of 1 or 5mg/kg βAE showed subtle motor abnormalities (e.g., slight loss of righting reflex) while repeated cycles of 10mg/kg βAE treatment resulted in obvious motor and behavioral changes. Rats receiving 1mg/kg βAE had no brainstem lesions whereas some rats treated with 5mg/kg βAE and all rats treated with 10 mg/kg βAE had brainstem lesions. Brainstem lesions were observed after as few as five cycles and were characterized by gliosis, satellitosis and progressive necrosis in motor neurons of the

Increased MMP-9 and TIMP-1 in mouse neonatal brain and plasma and in human neonatal plasma after hypoxia-ischemia: a potential marker of neonatal encephalopathy.

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Bednarek, Nathalie; Svedin, Pernilla; Garnotel, Roselyne; Favrais, Géraldine; Loron, Gauthier; Schwendiman, Leslie; Hagberg, Henrik; Morville, Patrice; Mallard, Carina; Gressens, Pierre

2012-01-01

To implement neuroprotective strategies in newborns, sensitive and specific biomarkers are needed for identifying those who are at risk for brain damage. We evaluated the effectiveness of matrix metalloproteinases (MMPs) and their naturally occurring tissue inhibitors of metalloproteinases (TIMPs) in predicting neonatal encephalopathy (NE) damage in newborns. Plasma MMP-9 and TIMP-1 levels were upregulated as early as 1 h after the HI insult but not did not show such elevations after other types of injury (ibotenate-induced excitotoxicity, hypoxia, lipopolysaccharide-induced inflammation), and brain levels reflected this increase soon thereafter. We confirmed these results by carrying out plasma MMP-9 and TIMP-1 measurements in human newborns with NE. In these infants, protein levels of MMP-9 and TIMP-1 were found to be elevated during a short window up to 6 h after birth. This feature is particularly useful in identifying newborns in need of neuroprotection. A second peak observed 72 h after birth is possibly related to the second phase of energy failure after a HI insult. Our data, although preliminary, support the use of MMP-9 and TIMP-1 as early biomarkers for the presence and extent of perinatal brain injury in human term newborns. We first used a mouse model of neonatal HI injury to explore mechanistic aspects such as the time course of these markers after the hypoxia-ischemia event, and the correlation between the levels of these candidate markers in brain and plasma.

Enterobacter sakazakii brain abscess in the neonate: the importance of neuroradiologic imaging

International Nuclear Information System (INIS)

Burdette, J.H.; Santos, C.

2000-01-01

Background. Enterobacter sakazakii is a rare but important cause of life-threatening neonatal sepsis and meningitis complicated by the development of brain abscess. Objective. Given the neurotropic qualities of this organism, early diagnosis and treatment are crucial as a poor prognosis follows brain abscess formation. Materials and methods. Cross-sectional imaging (CT and MRI) play an important role in the diagnostic work-up. Conclusion. A biopsy-proven case of E. sakazakii brain abscess, which was diagnosed on MR images, is presented, and the importance of prompt radiologic imaging of the central nervous system in the work-up of patients with this life-threatening disease is discussed. (orig.)

Repair of neonatal brain injury : bringing stem cell-based therapy into clinical practice

NARCIS (Netherlands)

Wagenaar, Nienke; Nijboer, Cora H.; van Bel, Frank

2017-01-01

Hypoxic-ischaemic brain injury is one of most important causes of neonatal mortality and long-term neurological morbidity in infants born at term. At present, only hypothermia in infants with perinatal hypoxic-ischaemic encephalopathy has shown benefit as a neuroprotective strategy. Otherwise,

Bumetanide augments the neuroprotective efficacy of phenobarbital plus hypothermia in a neonatal hypoxia-ischemia model

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Liu, YiQing; Shangguan, Yu; Barks, John D.E.; Silverstein, Faye S.

2014-01-01

The NaKCl cotransporter NKCC1 facilitates intraneuronal chloride accumulation in the developing brain. Bumetanide, a clinically available diuretic, inhibits this chloride transporter, and augments the antiepileptic effects of phenobarbital in neonatal rodents. In a neonatal cerebral hypoxia-ischemia (HI) model, elicited by right carotid ligation, followed by 90 min 8% O2 exposure in 7-day-old(P7) rats, phenobarbital(PB) increases the neuroprotective efficacy of hypothermia. We evaluated whether bumetanide influenced the neuroprotective efficacy of combination treatment with PB and hypothermia(HT). P7 rats underwent HI lesioning; 15 min later, all received PB (30 mg/kg). 10 min later, half received bumetanide (10 mg/kg, PB-HT+BUM) and half received saline (PB-HT+SAL). One hour after HI, all were cooled (30°C, 3h). Contralateral forepaw sensorimotor function and brain damage were evaluated 1 to 4 weeks later. Forepaw functional measures were close to normal in the PB-HT+BUM group, while deficits persisted in PB-HT+SAL controls; there were corresponding reductions in right cerebral hemisphere damage (at P35, % damage: PB-HT+BUM, 21±16 versus 38±20 in controls). These results provide evidence that NKCC1 inhibition amplifies phenobarbital bioactivity in the immature brain, and suggest that co-administration of phenobarbital and bumetanide may represent a clinically feasible therapy to augment the neuroprotective efficacy of therapeutic hypothermia in asphyxiated neonates. PMID:22398701

[Expression of c-jun protein after experimental rat brain concussion].

Science.gov (United States)

Wang, Feng; Li, Yong-hong

2010-02-01

To observe e-jun protein expression after rat brain concussion and explore the forensic pathologic markers following brain concussion. Fifty-five rats were randomly divided into brain concussion group and control group. The expression of c-jun protein was observed by immunohistochemistry. There were weak positive expression of c-jun protein in control group. In brain concussion group, however, some neutrons showed positive expression of c-jun protein at 15 min after brain concussion, and reach to the peak at 3 h after brain concussion. The research results suggest that detection of c-jun protein could be a marker to determine brain concussion and estimate injury time after brain concussion.

Neonatal hydrocephalus is a result of a block in folate handling and metabolism involving 10-formyltetrahydrofolate dehydrogenase.

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Naz, Naila; Jimenez, Alicia Requena; Sanjuan-Vilaplana, Anna; Gurney, Megan; Miyan, Jaleel

2016-08-01

Folate is vital in a range of biological processes and folate deficiency is associated with neurodevelopmental disorders such as neural tube defects and hydrocephalus (HC). 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is a key regulator for folate availability and metabolic interconversion for the supply of 1-carbon groups. In previous studies, we found a deficiency of FDH in CSF associated with the developmental deficit in congenital and neonatal HC. In this study, we therefore aimed to investigate the role of FDH in folate transport and metabolism during the brain development of the congenital hydrocephalic Texas (H-Tx) rat and normal (Sprague-Dawley) rats. We show that at embryonic (E) stage E18 and E20, FDH-positive cells and/or vesicles derived from the cortex can bind methyl-folate similarly to folate receptor alpha, the main folate transporter. Hydrocephalic rats expressed diminished nuclear FDH in both liver and brain at all postnatal (P) ages tested (P5, P15, and P20) together with a parallel increase in hepatic nuclear methyl-folate at P5 and cerebral methylfolate at P15 and P20. A similar relationship was found between FDH and 5-methyl cytosine, the main marker for DNA methylation. The data indicated that FDH binds and transports methylfolate in the brain and that decreased liver and brain nuclear expression of FDH is linked with decreased DNA methylation which could be a key factor in the developmental deficits associated with congenital and neonatal HC. Folate deficiency is associated with neurodevelopmental disorders such as neural tube defects and hydrocephalus. 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is a key regulator for folate availability and metabolic interconversion. We show that FDH binds and transports methylfolate in the brain. Moreover, we found that a deficiency of FDH in the nucleus of brain and liver is linked with decreased DNA methylation which could be a key factor in the developmental deficits associated with congenital and

Reduced Renshaw Recurrent Inhibition after Neonatal Sciatic Nerve Crush in Rats

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Liang Shu

2014-01-01

Full Text Available Renshaw recurrent inhibition (RI plays an important gated role in spinal motion circuit. Peripheral nerve injury is a common disease in clinic. Our current research was designed to investigate the change of the recurrent inhibitory function in the spinal cord after the peripheral nerve crush injury in neonatal rat. Sciatic nerve crush was performed on 5-day-old rat puppies and the recurrent inhibition between lateral gastrocnemius-soleus (LG-S and medial gastrocnemius (MG motor pools was assessed by conditioning monosynaptic reflexes (MSR elicited from the sectioned dorsal roots and recorded either from the LG-S and MG nerves by antidromic stimulation of the synergist muscle nerve. Our results demonstrated that the MSR recorded from both LG-S or MG nerves had larger amplitude and longer latency after neonatal sciatic nerve crush. The RI in both LG-S and MG motoneuron pools was significantly reduced to virtual loss (15–20% of the normal RI size even after a long recovery period upto 30 weeks after nerve crush. Further, the degree of the RI reduction after tibial nerve crush was much less than that after sciatic nerve crush indicatig that the neuron-muscle disconnection time is vital to the recovery of the spinal neuronal circuit function during reinnervation. In addition, sciatic nerve crush injury did not cause any spinal motor neuron loss but severally damaged peripheral muscle structure and function. In conclusion, our results suggest that peripheral nerve injury during neonatal early development period would cause a more sever spinal cord inhibitory circuit damage, particularly to the Renshaw recurrent inhibition pathway, which might be the target of neuroregeneration therapy.

Bumetanide enhances phenobarbital efficacy in a rat model of hypoxic neonatal seizures.

Science.gov (United States)

Cleary, Ryan T; Sun, Hongyu; Huynh, Thanhthao; Manning, Simon M; Li, Yijun; Rotenberg, Alexander; Talos, Delia M; Kahle, Kristopher T; Jackson, Michele; Rakhade, Sanjay N; Berry, Gerard T; Berry, Gerard; Jensen, Frances E

2013-01-01

Neonatal seizures can be refractory to conventional anticonvulsants, and this may in part be due to a developmental increase in expression of the neuronal Na(+)-K(+)-2 Cl(-) cotransporter, NKCC1, and consequent paradoxical excitatory actions of GABAA receptors in the perinatal period. The most common cause of neonatal seizures is hypoxic encephalopathy, and here we show in an established model of neonatal hypoxia-induced seizures that the NKCC1 inhibitor, bumetanide, in combination with phenobarbital is significantly more effective than phenobarbital alone. A sensitive mass spectrometry assay revealed that bumetanide concentrations in serum and brain were dose-dependent, and the expression of NKCC1 protein transiently increased in cortex and hippocampus after hypoxic seizures. Importantly, the low doses of phenobarbital and bumetanide used in the study did not increase constitutive apoptosis, alone or in combination. Perforated patch clamp recordings from ex vivo hippocampal slices removed following seizures revealed that phenobarbital and bumetanide largely reversed seizure-induced changes in EGABA. Taken together, these data provide preclinical support for clinical trials of bumetanide in human neonates at risk for hypoxic encephalopathy and seizures.

Neonatal tobacco smoke reduces thermogenesis capacity in brown adipose tissue in adult rats

Directory of Open Access Journals (Sweden)

T.C. Peixoto

2018-04-01

Full Text Available Maternal smoking is a risk factor for progeny obesity. We have previously shown, in a rat model of neonatal tobacco smoke exposure, a mild increase in food intake and a considerable increase in visceral adiposity in the adult offspring. Males also had secondary hyperthyroidism, while females had only higher T4. Since brown adipose tissue (BAT hypofunction is related to obesity, here we tested the hypothesis that higher levels of thyroid hormones are not functional in BAT, suggesting a lower metabolic rate. We evaluated autonomic nerve activity in BAT and its function in adult rats that were exposed to tobacco smoke during lactation. At birth, litters were adjusted to 3 male and 3 female pups/litter. From postnatal day (PND 3 to 21, Wistar lactating rats and their pups were divided into SE group, smoke-exposed in a cigarette smoking machine (4 times/day and C group, exposed to filtered air. Offspring were sacrificed at PND180. Adult SE rats of both genders had lower interscapular BAT autonomic nervous system activity, with higher BAT mass but no change in morphology. BAT UCP1 and CPT1a protein levels were decreased in the SE groups of both genders. Male SE rats had lower β3-AR, TRα1, and TRβ1 expression while females showed lower PGC1α expression. BAT Dio2 mRNA and hypothalamic POMC and MC4R levels were similar between groups. Hypothalamic pAMPK level was higher in SE males and lower in SE females. Thus, neonatal cigarette smoke exposure induces lower BAT thermogenic capacity, which can be obesogenic at adulthood.

Neonatal tobacco smoke reduces thermogenesis capacity in brown adipose tissue in adult rats.

Science.gov (United States)

Peixoto, T C; Moura, E G; Oliveira, E; Younes-Rapozo, V; Soares, P N; Rodrigues, V S T; Santos, T R; Peixoto-Silva, N; Carvalho, J C; Calvino, C; Conceição, E P S; Guarda, D S; Claudio-Neto, S; Manhães, A C; Lisboa, P C

2018-01-01

Maternal smoking is a risk factor for progeny obesity. We have previously shown, in a rat model of neonatal tobacco smoke exposure, a mild increase in food intake and a considerable increase in visceral adiposity in the adult offspring. Males also had secondary hyperthyroidism, while females had only higher T4. Since brown adipose tissue (BAT) hypofunction is related to obesity, here we tested the hypothesis that higher levels of thyroid hormones are not functional in BAT, suggesting a lower metabolic rate. We evaluated autonomic nerve activity in BAT and its function in adult rats that were exposed to tobacco smoke during lactation. At birth, litters were adjusted to 3 male and 3 female pups/litter. From postnatal day (PND) 3 to 21, Wistar lactating rats and their pups were divided into SE group, smoke-exposed in a cigarette smoking machine (4 times/day) and C group, exposed to filtered air. Offspring were sacrificed at PND180. Adult SE rats of both genders had lower interscapular BAT autonomic nervous system activity, with higher BAT mass but no change in morphology. BAT UCP1 and CPT1a protein levels were decreased in the SE groups of both genders. Male SE rats had lower β3-AR, TRα1, and TRβ1 expression while females showed lower PGC1α expression. BAT Dio2 mRNA and hypothalamic POMC and MC4R levels were similar between groups. Hypothalamic pAMPK level was higher in SE males and lower in SE females. Thus, neonatal cigarette smoke exposure induces lower BAT thermogenic capacity, which can be obesogenic at adulthood.

Independent mediation of unconditioned motor behavior by striatal D1 and D2 receptors in rats depleted of dopamine as neonates.

Science.gov (United States)

Bruno, J P; Byrnes, E M; Johnson, B J

1995-11-01

The effects of systemic administration of DA receptor antagonists suggest that unconditioned motor behavior in rats depleted of DA as neonates continues to be dependent upon dopaminergic transmission, yet the specific contribution of D1 and D2 receptors to these behaviors has been altered. The purpose of the present study was to determine whether these depletion-induced receptor changes are occurring at the level of striatal DA terminals and their targets. The ability of bilateral intrastriatal injections (0.5 microliter) of DA receptor antagonists to induce motoric deficits was determined in adult rats treated with vehicle or 6-OHDA (100 micrograms, intraventricular) on postnatal day 3. Administration of the D1-like antagonist SCH 23390 (0.5-2.0 micrograms) or the D2-like antagonist clebopride (1.0-4.0 micrograms) induced dose-dependent akinesia, catalepsy, and somatosensory neglect in vehicle-treated controls. In contrast, neither antagonist produced deficits in rats depleted of forebrain DA as neonates. However, combined administration of SCH 23390 + clebopride induced similar akinesia, catalepsy, and somatosensory neglect in both controls and DA depleted animals. Animals depleted of DA were more sensitive than controls to the low doses of this combined D1 + D2 antagonism. These results demonstrate that activation of striatal DA receptors remains necessary for unconditioned motor behavior in rats depleted of DA as neonates. However, the specific contributions of D1- and D2-like receptors to these behaviors differ between intact animals and those depleted of DA as neonates. The ability of endogenous DA acting at either D1 or D2 receptors to support spontaneous motor behavior in rats depleted of DA as neonates may contribute to their relative sparing from parkinsonian deficits.

5-HT modulation of multiple inward rectifiers in motoneurons in intact preparations of the neonatal rat spinal cord

DEFF Research Database (Denmark)

Kjaerulff, Ole; Kiehn, Ole

2001-01-01

This study introduces novel aspects of inward rectification in neonatal rat spinal motoneurons (MNs) and its modulation by serotonin (5-HT). Whole cell tight-seal recordings were made from MNs in an isolated lumbar spinal cord preparation from rats 1-2 days of age. In voltage clamp, hyperpolarizi...

Increase of long-term 'diabesity' risk, hyperphagia, and altered hypothalamic neuropeptide expression in neonatally overnourished 'small-for-gestational-age' (SGA rats.

Directory of Open Access Journals (Sweden)

Karen Schellong

Full Text Available BACKGROUND: Epidemiological data have shown long-term health adversity in low birth weight subjects, especially concerning the metabolic syndrome and 'diabesity' risk. Alterations in adult food intake have been suggested to be causally involved. Responsible mechanisms remain unclear. METHODS AND FINDINGS: By rearing in normal (NL vs. small litters (SL, small-for-gestational-age (SGA rats were neonatally exposed to either normal (SGA-in-NL or over-feeding (SGA-in-SL, and followed up into late adult age as compared to normally reared appropriate-for-gestational-age control rats (AGA-in-NL. SGA-in-SL rats displayed rapid neonatal weight gain within one week after birth, while SGA-in-NL growth caught up only at juvenile age (day 60, as compared to AGA-in-NL controls. In adulthood, an increase in lipids, leptin, insulin, insulin/glucose-ratio (all p<0.05, and hyperphagia under normal chow as well as high-energy/high-fat diet, modelling modern 'westernized' lifestyle, were observed only in SGA-in-SL as compared to both SGA-in-NL and AGA-in-NL rats (p<0.05. Lasercapture microdissection (LMD-based neuropeptide expression analyses in single neuron pools of the arcuate hypothalamic nucleus (ARC revealed a significant shift towards down-regulation of the anorexigenic melanocortinergic system (proopiomelanocortin, Pomc in SGA-in-SL rats (p<0.05. Neuropeptide expression within the orexigenic system (neuropeptide Y (Npy, agouti-related-peptide (Agrp and galanin (Gal was not significantly altered. In essence, the 'orexigenic index', proposed here as a neuroendocrine 'net-indicator', was increased in SGA-in-SL regarding Npy/Pomc expression (p<0.01, correlated to food intake (p<0.05. CONCLUSION: Adult SGA rats developed increased 'diabesity' risk only if exposed to neonatal overfeeding. Hypothalamic malprogramming towards decreased anorexigenic activity was involved into the pathophysiology of this neonatally acquired adverse phenotype. Neonatal overfeeding

Plasticity in One Hemisphere, Control From Two: Adaptation in Descending Motor Pathways After Unilateral Corticospinal Injury in Neonatal Rats

Directory of Open Access Journals (Sweden)

Tong-Chun Wen

2018-04-01

Full Text Available After injury to the corticospinal tract (CST in early development there is large-scale adaptation of descending motor pathways. Some studies suggest the uninjured hemisphere controls the impaired forelimb, while others suggest that the injured hemisphere does; these pathways have never been compared directly. We tested the contribution of each motor cortex to the recovery forelimb function after neonatal injury of the CST. We cut the left pyramid (pyramidotomy of postnatal day 7 rats, which caused a measurable impairment of the right forelimb. We used pharmacological inactivation of each motor cortex to test its contribution to a skilled reach and supination task. Rats with neonatal pyramidotomy were further impaired by inactivation of motor cortex in both the injured and the uninjured hemispheres, while the forelimb of uninjured rats was impaired only from the contralateral motor cortex. Thus, inactivation demonstrated motor control from each motor cortex. In contrast, physiological and anatomical interrogation of these pathways support adaptations only in the uninjured hemisphere. Intracortical microstimulation of motor cortex in the uninjured hemisphere of rats with neonatal pyramidotomy produced responses from both forelimbs, while stimulation of the injured hemisphere did not elicit responses from either forelimb. Both anterograde and retrograde tracers were used to label corticofugal pathways. There was no increased plasticity from the injured hemisphere, either from cortex to the red nucleus or the red nucleus to the spinal cord. In contrast, there were very strong CST connections to both halves of the spinal cord from the uninjured motor cortex. Retrograde tracing produced maps of each forelimb within the uninjured hemisphere, and these were partly segregated. This suggests that the uninjured hemisphere may encode separate control of the unimpaired and the impaired forelimbs of rats with neonatal pyramidotomy.

Plasticity in One Hemisphere, Control From Two: Adaptation in Descending Motor Pathways After Unilateral Corticospinal Injury in Neonatal Rats.

Science.gov (United States)

Wen, Tong-Chun; Lall, Sophia; Pagnotta, Corey; Markward, James; Gupta, Disha; Ratnadurai-Giridharan, Shivakeshavan; Bucci, Jacqueline; Greenwald, Lucy; Klugman, Madelyne; Hill, N Jeremy; Carmel, Jason B

2018-01-01

After injury to the corticospinal tract (CST) in early development there is large-scale adaptation of descending motor pathways. Some studies suggest the uninjured hemisphere controls the impaired forelimb, while others suggest that the injured hemisphere does; these pathways have never been compared directly. We tested the contribution of each motor cortex to the recovery forelimb function after neonatal injury of the CST. We cut the left pyramid (pyramidotomy) of postnatal day 7 rats, which caused a measurable impairment of the right forelimb. We used pharmacological inactivation of each motor cortex to test its contribution to a skilled reach and supination task. Rats with neonatal pyramidotomy were further impaired by inactivation of motor cortex in both the injured and the uninjured hemispheres, while the forelimb of uninjured rats was impaired only from the contralateral motor cortex. Thus, inactivation demonstrated motor control from each motor cortex. In contrast, physiological and anatomical interrogation of these pathways support adaptations only in the uninjured hemisphere. Intracortical microstimulation of motor cortex in the uninjured hemisphere of rats with neonatal pyramidotomy produced responses from both forelimbs, while stimulation of the injured hemisphere did not elicit responses from either forelimb. Both anterograde and retrograde tracers were used to label corticofugal pathways. There was no increased plasticity from the injured hemisphere, either from cortex to the red nucleus or the red nucleus to the spinal cord. In contrast, there were very strong CST connections to both halves of the spinal cord from the uninjured motor cortex. Retrograde tracing produced maps of each forelimb within the uninjured hemisphere, and these were partly segregated. This suggests that the uninjured hemisphere may encode separate control of the unimpaired and the impaired forelimbs of rats with neonatal pyramidotomy.

Brain glucose content in fetuses of ethanol-fed rats

Energy Technology Data Exchange (ETDEWEB)

Pullen, G.; Singh, S.P.; Snyder, A.K.; Hoffen, B.

1986-03-01

The authors have previously demonstrated impaired placental glucose transfer and fetal hypoglycemia in association with ethanol ingestion by pregnant rats. The present study examines the relationship between glucose availability and fetal brain growth under the same conditions. Rats (EF) were fed ethanol (30% of caloric intake) in liquid diet throughout gestation. Controls received isocaloric diet without ethanol by pair-feeding (PF) or ad libitum (AF). On the 22nd day of gestation fetuses were obtained by cesarean section. Fetal brains were removed and freeze-clamped. Brain weight was significantly reduced (p < 0.001) by maternal ethanol ingestion (206 +/- 2, 212 +/- 4 and 194 +/- 2 mg in AF, FP and EF fetuses respectively). Similarly, fetal brain glucose content was lower (p < 0.05) in the EF group (14.3 +/- 0.9 mmoles/g dry weight) than in the PF (18.6 +/- 1.0) or the AF (16.2 +/- 0.9) groups. The protein: DNA ratio, an indicator of cell size, correlated positively (r = 0.371, p < 0.005) with brain glucose content. In conclusion, maternal ethanol ingestion resulted in lower brain weight and reduced brain glucose content. Glucose availability may be a significant factor in the determination of cell size in the fetal rat brain.

Fetal and neonatal brain injury: mechanisms, management, and the risks of practice

National Research Council Canada - National Science Library

Stevenson, David K; Benitz, William E; Sunshine, Philip

2003-01-01

..., imaging studies, and laboratory measurements can identify the timing and severity of the injury event. Despite these advances, fetal and neonatal brain injury remains a major concern with devastating consequences. It is hoped that this definitive account will provide the clinician not only with a better understanding of the mechanisms involved but also with...

Hydrophilic solute transport across the rat blood-brain barrier

International Nuclear Information System (INIS)

Lucchesi, K.J.

1987-01-01

Brain capillary permeability-surface area products (PS) of hydrophilic solutes ranging in size from 180 to 5,500 Daltons were measured in rats according to the method of Ohno, Pettigrew and Rapoport. The distribution volume of 70 KD dextran at 10 minutes after i.v. injection was also measured to determine the residual volume of blood in brain tissue at the time of sacrifice. Small test solutes were injected in pairs in order to elucidate whether their transfer into the brain proceeds by diffusion through water- or lipid-filled channels or by vesicular transport. This issue was examined in rats whose blood-brain barrier (BBB) was presumed to be intact (untreated) and in rats that received intracarotid infusions to open the BBB (isosmotic salt (ISS) and hyperosmolar arabinose). Ohno PS values of 3 H-inulin and 14 C-L-glucose in untreated rats were found to decrease as the labelling time was lengthened. This was evidence that a rapidly equilibrating compartment exists between blood and brain that renders the Ohno two-compartment model inadequate for computing true transfer rate constants. When the data were reanalyzed using a multi-compartment graphical analysis, solutes with different molecular radii were found to enter the brain at approximately equal rates. Furthermore, unidirectional transport is likely to be initiated by solute adsorption to a glycocalyx coat on the luminal surface of brain capillary endothelium. Apparently, more inulin than L-glucose was adsorbed, which may account for its slightly faster transfer across the BBB. After rats were treated with intracarotid infusions of ISS or hyperosmolar arabinose, solute PS values were significantly increased, but the ratio of PS for each of the solute pairs approached that of their free-diffusion coefficients

Testosterone supplementation restores vasopressin innervation in the senescent rat brain

NARCIS (Netherlands)

Goudsmit, E.; Fliers, E.; Swaab, D. F.

1988-01-01

The vasopressin (AVP) innervation in the male rat brain is decreased in senescence. This decrease is particularly pronounced in brain regions where AVP fiber density is dependent on plasma levels of sex steroids. Since plasma testosterone levels decrease progressively with age in the rat, the

Quantification of ante-mortem hypoxic ischemic brain injury by post-mortem cerebral magnetic resonance imaging in neonatal encephalopathy.

Science.gov (United States)

Montaldo, Paolo; Chaban, Badr; Lally, Peter J; Sebire, Neil J; Taylor, Andrew M; Thayyil, Sudhin

2015-11-01

Post-mortem (PM) magnetic resonance imaging (MRI) is increasingly used as an alternative to conventional autopsy in babies dying from neonatal encephalopathy. However, the confounding effect of post-mortem changes on the detection of ante-mortem ischemic injury is unclear. We examined whether quantitative MR measurements can accurately distinguish ante-mortem ischemic brain injury from artifacts using post-mortem MRI. We compared PM brain MRI (1.5 T Siemens, Avanto) in 7 infants who died with neonatal encephalopathy (NE) of presumed hypoxic-ischemic origin with 7 newborn infants who had sudden unexplained neonatal death (SUND controls) without evidence of hypoxic-ischemic brain injury at autopsy. We measured apparent diffusion coefficients (ADCs), T1-weighted signal intensity ratios (SIRs) compared to vitreous humor and T2 relaxation times from 19 predefined brain areas typically involved in neonatal encephalopathy. There were no differences in mean ADC values, SIRs on T1-weighted images or T2 relaxation times in any of the 19 predefined brain areas between NE and SUND infants. All MRI images showed loss of cortical gray/white matter differentiation, loss of the normal high signal intensity (SI) in the posterior limb of the internal capsule on T1-weighted images, and high white matter SI on T2-weighted images. Normal post-mortem changes may be easily mistaken for ante-mortem ischemic injury, and current PM MRI quantitative assessment cannot reliably distinguish these. These findings may have important implications for appropriate interpretation of PM imaging findings, especially in medico-legal practice. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Dietary choline during periadolescence attenuates cognitive damage caused by neonatal maternal separation in male rats.

Science.gov (United States)

Moreno Gudiño, Hayarelis; Carías Picón, Diamela; de Brugada Sauras, Isabel

2017-07-01

Choline (Ch) is an essential nutrient that acts as a cognitive facilitator when administered during perinatal periods, and it has been recognised as a 'pharmacological' agent that can ease cognitive dysfunctions provoked by exposure to damaging stimuli during early developmental stages. The aim of the present work is to determine whether providing a diet rich in Ch would reduce the severity of the memory deficit provoked by a neonatal stress episode in male adult rats. The effect of Ch on memory was measured using memory tasks such as object and place recognition. Ontogenetic manipulations were conducted during two sensitive developmental periods. During the first post-natal (PN) 14 days, only the male rat pups were selected and half of them were separated from the mother, group maternal separation (MS). Subsequently, during periadolescence (PN 21-60), the rats were exposed to a deficient (DEF = 0 g/kg Ch chloride), sufficient (CON = 1.1 g/kg Ch chloride), or supplemented (SUP = 5 g/kg Ch chloride) diets for this nutrient. The results indicated that for group MS, only rats fed with the SUP diet were able to recognise the familiar object and place that had been experienced 24 hours before, unlike groups DEF and CON. In addition, whereas rats in the non-separated group (No-MS) recognised the object independently of the diet, only rats that received a DEF diet failed to recognise the place, showing that a Ch deficit affects spatial memory tasks. These results show that Ch supplementation during periadolescence can attenuate the memory deficit provoked by extended neonatal stress.

A comparative study of myosin and its subunits in adult and neonatal-rat hearts and in rat heart cells from young and old cultures.

OpenAIRE

Ghanbari, H A; McCarl, R L

1980-01-01

A possible explanation for the decrease in myosin Ca2+-dependent ATPase activity as rat heart cells age in culture is presented. The subunit structure and enzyme kinetics of myosin from adult and neonatal rat hearts and from rat heart cells of young and old cultures are compared. These studies indicate that the loss in Ca-ATPase activity of myosin from older cultures was an intrinsic property of the myosin itself. Myofibrillar fractions from the indicated four sources showed no qualitative or...

Congenital Malformations in Neonates after irradiation of Rats During Pregnancy

International Nuclear Information System (INIS)

Abdel-Gawad, I.I.; Mohammad, M.H.M.

2000-01-01

Radiation is considered a teratogen during the whole period of embryonic development and fetal growth. However, the time of gestation at which irradiation takes place will affect the type of congenital malformation Induced. A study was carried out to observe various forms of congenital malformations induced after irradiation of pregnant rats to 1,2 and 3 Gy on the 9 th , 12 th and 15 th days of gestation. Various types of congenital malformations were observed in the neonates of irradiated animals as compared to controls. Most of the malformations were observed in neonates of animals irradiated with 2 and 3 Gy on the 12 th and 15 th days of gestation. This confirms that developmental anomalies occur mostly during the period of organ development. Other periods of gestation are less vulnerable to, induction of malformation after irradiation. Some representative photographs of the malformations induced such as penguin shape, absence of tail, low set ears, growth retardation and others are illustrated in the text

Effect of an NCAM mimetic peptide FGL on impairment in spatial learning and memory after neonatal phencyclidine treatment in rats

DEFF Research Database (Denmark)

Secher, Thomas; Berezin, Vladimir; Bock, Elisabeth

2008-01-01

treatment regimen where FGL was administered throughout development. Rats were tested as adults for spatial reference memory, reversal learning, and working memory in the Morris water maze. The PCP-treated rats demonstrated a robust impairment in working memory and reversal learning. However, the long-term......The FGL peptide is a neural cell adhesion molecule-derived fibroblast growth factor receptor agonist. FGL has both neurotrophic and memory enhancing properties. Neonatal phencyclidine (PCP) treatment on postnatal days 7, 9, and 11 has been shown to result in long-lasting behavioral abnormalities......, including cognitive impairment relevant to schizophrenia. The present study investigated the effect of FGL on spatial learning and memory deficits induced by neonatal PCP treatment. Rat pups were treated with 30mg/kg PCP on postnatal days 7, 9, and 11. Additionally, the rats were subjected to a chronic FGL...

Development of the adrenal axis in the neonatal rat

Energy Technology Data Exchange (ETDEWEB)

Guillet, Ronnie [Univ. of Rochester, NY (United States)

1977-01-01

Plasma corticosterone and ACTH concentrations were determined in neonatal rats 1, 7, 14, and 21 days old, under a variety of experimental conditions, to obtain more information on the postnatal development of the rat hypothalamo-adrenal (HHA) axis. The results indicate that: (1) there is a diminution followed by an increase in responsiveness of the adrenal gland, but the pituitary response to direct hormonal stimulation is unchanged during the first three postnatal weeks; (2) continued stimulation of the adrenal by ACTH or of the central nervous system (CNS) or hypothalamus by corticosterone is necessary during early postnatal development to allow normal maturation of the HHA axis; and (3) feedback inhibition is operative by birth, at least to a moderate degree. Taken together, the studies suggest that both the adrenal and pituitary glands are potentially functional at birth, but that the hypothalamic and CNS mediators of the stress response are not mature until at least the second or third postnatal week. (ERB)

Disruption to functional networks in neonates with perinatal brain injury predicts motor skills at 8 months.

Science.gov (United States)

Linke, Annika C; Wild, Conor; Zubiaurre-Elorza, Leire; Herzmann, Charlotte; Duffy, Hester; Han, Victor K; Lee, David S C; Cusack, Rhodri

2018-01-01

Functional connectivity magnetic resonance imaging (fcMRI) of neonates with perinatal brain injury could improve prediction of motor impairment before symptoms manifest, and establish how early brain organization relates to subsequent development. This cohort study is the first to describe and quantitatively assess functional brain networks and their relation to later motor skills in neonates with a diverse range of perinatal brain injuries. Infants ( n  = 65, included in final analyses: n  = 53) were recruited from the neonatal intensive care unit (NICU) and were stratified based on their age at birth (premature vs. term), and on whether neuropathology was diagnosed from structural MRI. Functional brain networks and a measure of disruption to functional connectivity were obtained from 14 min of fcMRI acquired during natural sleep at term-equivalent age. Disruption to connectivity of the somatomotor and frontoparietal executive networks predicted motor impairment at 4 and 8 months. This disruption in functional connectivity was not found to be driven by differences between clinical groups, or by any of the specific measures we captured to describe the clinical course. fcMRI was predictive over and above other clinical measures available at discharge from the NICU, including structural MRI. Motor learning was affected by disruption to somatomotor networks, but also frontoparietal executive networks, which supports the functional importance of these networks in early development. Disruption to these two networks might be best addressed by distinct intervention strategies.

Evaluation of an automatic brain segmentation method developed for neonates on adult MR brain images

Science.gov (United States)

Moeskops, Pim; Viergever, Max A.; Benders, Manon J. N. L.; Išgum, Ivana

2015-03-01

Automatic brain tissue segmentation is of clinical relevance in images acquired at all ages. The literature presents a clear distinction between methods developed for MR images of infants, and methods developed for images of adults. The aim of this work is to evaluate a method developed for neonatal images in the segmentation of adult images. The evaluated method employs supervised voxel classification in subsequent stages, exploiting spatial and intensity information. Evaluation was performed using images available within the MRBrainS13 challenge. The obtained average Dice coefficients were 85.77% for grey matter, 88.66% for white matter, 81.08% for cerebrospinal fluid, 95.65% for cerebrum, and 96.92% for intracranial cavity, currently resulting in the best overall ranking. The possibility of applying the same method to neonatal as well as adult images can be of great value in cross-sectional studies that include a wide age range.

Glucose and amino acid metabolism in rat brain during sustained hypoglycemia

International Nuclear Information System (INIS)

Wong, K.L.; Tyce, G.M.

1983-01-01

The metabolism of glucose in brains during sustained hypoglycemia was studied. [U- 14 C]Glucose (20 microCi) was injected into control rats, and into rats at 2.5 hr after a bolus injection of 2 units of insulin followed by a continuous infusion of 0.2 units/100 g rat/hr. This regimen of insulin injection was found to result in steady-state plasma glucose levels between 2.5 and 3.5 mumol per ml. In the brains of control rats carbon was transferred rapidly from glucose to glutamate, glutamine, gamma-aminobutyric acid and aspartate and this carbon was retained in the amino acids for at least 60 min. In the brains of hypoglycemic rats, the conversion of carbon from glucose to amino acids was increased in the first 15 min after injection. After 15 min, the specific activity of the amino acids decreased in insulin-treated rats but not in the controls. The concentrations of alanine, glutamate, and gamma-amino-butyric acid decreased, and the concentration of aspartate increased, in the brains of the hypoglycemic rats. The concentration of pyridoxal-5'-phosphate, a cofactor in many of the reactions whereby these amino acids are formed from tricarboxylic acid cycle intermediates, was less in the insulin-treated rats than in the controls. These data provide evidence that glutamate, glutamine, aspartate, and GABA can serve as energy sources in brain during insulin-induced hypoglycemia

The dorso-lateral recess of the hypothalamic ventricle in neonatal rats.

Science.gov (United States)

Menéndez, A; Alvarez-Uría, M

1987-10-01

Light and electron microscopy of the hypothalamic ventricle in neonatal rats demonstrate morphological specializations of the ventricular wall at the level of the premammillary region of the third ventricle. The morphological features are: (1) A ventricular recess that we have called the "hypothalamic dorso-lateral recess" (HDR). (2) The presence of intraventricular capillaries near the dorso-lateral recess. (3) The HDR possessing a specialized ependymal lining; this consists of non-ciliated cells with short microvilli and bleb-like processes. (4) The existence of cerebrospinal fluid-contacting neurons within the HDR. (5) The presence of numerous phagocytic supraependymal cells. The HDR is not found in adult rats. This indicates that the dorso-lateral recess may play a physiological role during development.

Neonatal neurosonography

Energy Technology Data Exchange (ETDEWEB)

Riccabona, Michael, E-mail: michael.riccabona@klinikum-graz.at

2014-09-15

Paediatric and particularly neonatal neurosonography still remains a mainstay of imaging the neonatal brain. It can be performed at the bedside without any need for sedation or specific monitoring. There are a number of neurologic conditions that significantly influence morbidity and mortality in neonates and infants related to the brain and the spinal cord; most of them can be addressed by ultrasonography (US). However, with the introduction of first CT and then MRI, neonatal neurosonography is increasingly considered just a basic first line technique that offers only orienting information and does not deliver much relevant information. This is partially caused by inferior US performance – either by restricted availability of modern equipment or by lack of specialized expertise in performing and reading neurosonographic scans. This essay tries to highlight the value and potential of US in the neonatal brain and briefly touching also on the spinal cord imaging. The common pathologies and their US appearance as well as typical indication and applications of neurosonography are listed. The review aims at encouraging paediatric radiologists to reorient there imaging algorithms and skills towards the potential of modern neurosonography, particularly in the view of efficacy, considering growing economic pressure, and the low invasiveness as well as the good availability of US that can easily be repeated any time at the bedside.

Intestinal absorption and retention of cadmium in neonatal pigs compared to rats and guinea pigs

International Nuclear Information System (INIS)

Sasser, L.B.; Jarboe, G.E.

1980-01-01

The purpose of this study was to measure intestinal absorption and retention of cadmium in the newborn pig and to compare data from the pig, rat and guinea pig, three species that differ greatly in their ability to absorb macromolecules at birth. Newborn pigs were administered a single oral dose of 50 μCi of /sup 115m/Cd 24 hours after birth and killed at intervals between 1 and 14 days after dosing. Cd absorption and gastrointestinal retention were then determined; these data were compared with similar data from the rat and guinea pig. Cd absorption in the neonate appears to be a two-step process; mucosal uptake of Cd from the lumen, probably by pinocytosis, followed by transfer of a portion of this Cd into the body. This transfer process is similar, but does not entirely coincide with changes associated with protein absorption in the neonate

Behavioral and histological outcomes following neonatal HI injury in a preterm (P3) and term (P7) rodent model.

Science.gov (United States)

Alexander, M; Garbus, H; Smith, A L; Rosenkrantz, T S; Fitch, R H

2014-02-01

Hypoxia-ischemia (HI) occurs when blood and/or oxygen delivery to the brain is compromised. HI injuries can occur in infants born prematurely (HI populations, brain injury is associated with subsequent behavioral deficits. Neonatal HI injury can be modeled in rodents (e.g., the Rice-Vannucci method, via cautery of right carotid followed by hypoxia). When this injury is induced early in life (between postnatal day (P)1-5), neuropathologies typical of human preterm HI are modeled. When injury is induced later (P7-12), neuropathologies typical of those seen in HI term infants are modeled. The current study sought to characterize the similarities/differences between outcomes following early (P3) and late (P7) HI injury in rats. Male rats with HI injury on P3 or P7, as well as sham controls, were tested on a variety of behavioral tasks in both juvenile and adult periods. Results showed that P7 HI rats displayed deficits on motor learning, rapid auditory processing (RAP), and other learning/memory tasks, as well as a reduction in volume in various neuroanatomical structures. P3 HI animals showed only transient deficits on RAP tasks in the juvenile period (but not in adulthood), yet robust deficits on a visual attention task in adulthood. P3 HI animals did not show any significant reductions in brain volume that we could detect. These data suggest that: (1) behavioral deficits following neonatal HI are task-specific depending on timing of injury; (2) P3 HI rats showed transient deficits on RAP tasks; (3) the more pervasive behavioral deficits seen following P7 HI injury were associated with substantial global tissue loss; and (4) persistent deficits in attention in P3 HI subjects might be linked to neural connectivity disturbances rather than a global loss of brain volume, given that no such pathology was found. These combined findings can be applied to our understanding of differing long-term outcomes following neonatal HI injury in premature versus term infants

Thymoquinone ameliorates lead-induced brain damage in Sprague Dawley rats.

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Radad, Khaled; Hassanein, Khaled; Al-Shraim, Mubarak; Moldzio, Rudolf; Rausch, Wolf-Dieter

2014-01-01

The present study aims to investigate the protective effects of thymoquinone, the major active ingredient of Nigella sativa seeds, against lead-induced brain damage in Sprague-Dawley rats. In which, 40 rats were divided into four groups (10 rats each). The first group served as control. The second, third and fourth groups received lead acetate, lead acetate and thymoquinone, and thymoquinone only, respectively, for one month. Lead acetate was given in drinking water at a concentration of 0.5 g/l (500 ppm). Thymoquinone was given daily at a dose of 20mg/kg b.w. in corn oil by gastric tube. Control and thymoquinone-treated rats showed normal brain histology. Treatment of rats with lead acetate was shown to produce degeneration of endothelial lining of brain blood vessels with peri-vascular cuffing of mononuclear cells consistent to lymphocytes, congestion of choroid plexus blood vessels, ischemic brain infarction, chromatolysis and neuronal degeneration, microglial reaction and neuronophagia, degeneration of hippocampal and cerebellar neurons, and axonal demyelination. On the other hand, co-administration of thymoquinone with lead acetate markedly decreased the incidence of lead acetate-induced pathological lesions. Thus the current study shed some light on the beneficial effects of thymoquinone against neurotoxic effects of lead in rats. Copyright © 2013 Elsevier GmbH. All rights reserved.

Regeneration of 5-HT fibers in hippocampal heterotopia of methylazoxymethanol-induced micrencephalic rats after neonatal 5,7-DHT injection.

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Nakamura, Arata; Kadowaki, Taro; Sakakibara, Shin-ichi; Yoshimoto, Kanji; Hirata, Koichi; Ueda, Shuichi

2010-03-01

In order to elucidate the regeneration properties of serotonergic fibers in the hippocampus of methylazoxymethanol acetate (MAM)-induced micrencephalic rats (MAM rats), we examined serotonergic regeneration in the hippocampus following neonatal intracisternal 5,7-dihydroxytryptamine (5,7-DHT) injection. Prenatal exposure to MAM resulted in the formation of hippocampal heterotopia in the dorsal hippocampus. Immunohistochemical and neurochemical analyses revealed hyperinnervation of serotonergic fibers in the hippocampus of MAM rats. After neonatal 5,7-DHT injection, most serotonergic fibers in the hippocampus of 2-week-old MAM rats had degenerated, while a small number of serotonergic fibers in the stratum lacunosum-moleculare (SLM) of the hippocampus and in the hilus adjacent to the granular cell layer of the dentate gyrus (DG) had not. Regenerating serotonergic fibers from the SLM first extended terminals into the hippocampal heterotopia, then fibers from the hilus reinnervated the DG and some fibers extended to the heterotopia. These findings suggest that the hippocampal heterotopia exerts trophic target effects for regenerating serotonergic fibers in the developmental period in micrencephalic rats.

Brain perfusion in acute and chronic hyperglycemia in rats

International Nuclear Information System (INIS)

Kikano, G.E.; LaManna, J.C.; Harik, S.I.

1989-01-01

Recent studies show that acute and chronic hyperglycemia cause a diffuse decrease in regional cerebral blood flow and that chronic hyperglycemia decreases the brain L-glucose space. Since these changes can be caused by a decreased density of perfused brain capillaries, we used 30 adult male Wistar rats to study the effect of acute and chronic hyperglycemia on (1) the brain intravascular space using radioiodinated albumin, (2) the anatomic density of brain capillaries using alkaline phosphatase histochemistry, and (3) the fraction of brain capillaries that are perfused using the fluorescein isothiocyanate-dextran method. Our results indicate that acute and chronic hyperglycemia do not affect the brain intravascular space nor the anatomic density of brain capillaries. Also, there were no differences in capillary recruitment among normoglycemic, acutely hyperglycemic, and chronically hyperglycemic rats. These results suggest that the shrinkage of the brain L-glucose space in chronic hyperglycemia is more likely due to changes in the blood-brain barrier permeability to L-glucose

Radioimmunoassay of met-enkephalin in microdissected areas of paraformaldehyde-fixed rat brain

International Nuclear Information System (INIS)

Correa, F.M.A.; Saavedra, J.M.

1984-01-01

The effects were studied of various sample preparation procedures on rat brain met-enkephalin content, measured by radioimmunoassay. Whole brain met-enkephalin content of rats killed by decapitation followed by immediate tissue freezing was similar to that of rats killed by microwave irradiation and to those of rats anesthetized with pentobarbital or halothane before killing, whether previously perfused with paraformaldehyde or not. In contrast, a decrease (up to 80%) in met-enkephalin concentrations was observed when brain samples were frozen and thawed to mimic the procedure utilized in the ''punch'' technique for analysis of discrete brain nuclei. This decrease was totally prevented by paraformaldehyde perfusion of the brain prior to sacrifice. Brain perfusion did not alter the amount of immunoassayable met-enkephalin extracted from tissue or its profile after Sephadex chromatography. Paraformaldehyde perfusion results in better morphological tissue preservation and facilitates the ''punch'' dissecting technique. Paraformaldehyde perfusion may be the procedure of choice for the measurement of neuropeptides in specific brain nuclei dissected by the ''punch'' technique

Incidence of brain tumours in rats exposed to an aerosol of 239PuO2

International Nuclear Information System (INIS)

Sanders, C.L.; Dagle, G.E.; Mahaffey, J.A.

1992-01-01

Incidence of brain tumours was investigated in 3390 female and male Wistar rats exposed to an aerosol of 239 PuO 2 , or as sham-exposed controls. Lung doses ranged from 0.05 to 22 Gy. In females, six brain tumours were found in 1058 control rats (incidence, 0.6%) and 24 brain tumours in 2134 rats exposed to Pu (incidence, 1.1%); the survival-adjusted level of significance was p = 0.29 for comparing control with exposed females. In males, two brain tumours were found in 60 control rats (incidence, 3.3%) and seven brain tumours in 138 rats exposed to Pu (incidence, 5.1%); the survival-adjusted level of significance was p = 0.33. Brain tumour incidence was about five times greater in male than in female rats (p = 0.0001), a highly significant sex difference in brain tumour incidence. Tumour types were distributed similarly among control and Pu-exposed groups of both sexes; most were astrocytomas. Mean lifespans for rats with brain tumours were not significantly different between control and Pu-exposed rats. (author)

Teaching Adult Rats Spinalized as Neonates to Walk Using Trunk Robotic Rehabilitation: Elements of Success, Failure, and Dependence.

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Udoekwere, Ubong I; Oza, Chintan S; Giszter, Simon F

2016-08-10

Robot therapy promotes functional recovery after spinal cord injury (SCI) in animal and clinical studies. Trunk actions are important in adult rats spinalized as neonates (NTX rats) that walk autonomously. Quadrupedal robot rehabilitation was tested using an implanted orthosis at the pelvis. Trunk cortical reorganization follows such rehabilitation. Here, we test the functional outcomes of such training. Robot impedance control at the pelvis allowed hindlimb, trunk, and forelimb mechanical interactions. Rats gradually increased weight support. Rats showed significant improvement in hindlimb stepping ability, quadrupedal weight support, and all measures examined. Function in NTX rats both before and after training showed bimodal distributions, with "poor" and "high weight support" groupings. A total of 35% of rats initially classified as "poor" were able to increase their weight-supported step measures to a level considered "high weight support" after robot training, thus moving between weight support groups. Recovered function in these rats persisted on treadmill with the robot both actuated and nonactuated, but returned to pretraining levels if they were completely disconnected from the robot. Locomotor recovery in robot rehabilitation of NTX rats thus likely included context dependence and/or incorporation of models of robot mechanics that became essential parts of their learned strategy. Such learned dependence is likely a hurdle to autonomy to be overcome for many robot locomotor therapies. Notwithstanding these limitations, trunk-based quadrupedal robot rehabilitation helped the rats to visit mechanical states they would never have achieved alone, to learn novel coordinations, and to achieve major improvements in locomotor function. Neonatal spinal transected rats without any weight support can be taught weight support as adults by using robot rehabilitation at trunk. No adult control rats with neonatal spinal transections spontaneously achieve similar changes

Neonatal finasteride administration decreases dopamine release in nucleus accumbens after alcohol and food presentation in adult male rats.

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Llidó, Anna; Bartolomé, Iris; Darbra, Sònia; Pallarès, Marc

2016-08-01

Endogenous levels of the neurosteroid (NS) allopregnanolone (AlloP) during neonatal stages are crucial for the correct development of the central nervous system (CNS). In a recent work we reported that the neonatal administration of AlloP or finasteride (Finas), an inhibitor of the enzyme 5α-reductase needed for AlloP synthesis, altered the voluntary consumption of ethanol and the ventrostriatal dopamine (DA) levels in adulthood, suggesting that neonatal NS manipulations can increase alcohol abuse vulnerability in adulthood. Moreover, other authors have associated neonatal NS alterations with diverse dopaminergic (DAergic) alterations. Thus, the aim of the present work is to analyse if manipulations of neonatal AlloP alter the DAergic response in the nucleus accumbens (NAcc) during alcohol intake in rats. We administered AlloP or Finas from postnatal day (PND) 5 to PND9. At PND98, we measured alcohol consumption using a two-bottle free-choice model (ethanol 10% (v/v)+glucose 3% (w/v), and glucose 3% (w/v)) for 12 days. On the last day of consumption, we measured the DA and 3,4-dihydroxyphenylacetic acid (DOPAC) release in NAcc in response to ethanol intake. The samples were obtained by means of in vivo microdialysis in freely moving rats, and DA and DOPAC levels were determined by means of high-performance liquid chromatography analysis (HPLC). The results revealed that neonatal Finas increased ethanol consumption in some days of the consumption phase, and decreased the DA release in the NAcc in response to solutions (ethanol+glucose) and food presentation. Taken together, these results suggest that neonatal NS alterations can affect alcohol rewarding properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Maternal or neonatal infection: association with neonatal encephalopathy outcomes.

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Jenster, Meike; Bonifacio, Sonia L; Ruel, Theodore; Rogers, Elizabeth E; Tam, Emily W; Partridge, John Colin; Barkovich, Anthony James; Ferriero, Donna M; Glass, Hannah C

2014-07-01

Perinatal infection may potentiate brain injury among children born preterm. The objective of this study was to examine whether maternal and/or neonatal infection are associated with adverse outcomes among term neonates with encephalopathy. This study is a cohort study of 258 term newborns with encephalopathy whose clinical records were examined for signs of maternal infection (chorioamnionitis) and infant infection (sepsis). Multivariate regression was used to assess associations between infection, pattern, and severity of injury on neonatal magnetic resonance imaging, as well as neurodevelopment at 30 mo (neuromotor examination, or Bayley Scales of Infant Development, second edition mental development index encephalopathy, chorioamnionitis was associated with a lower risk of brain injury and adverse outcomes, whereas signs of neonatal sepsis carried an elevated risk. The etiology of encephalopathy and timing of infection and its associated inflammatory response may influence whether infection potentiates or mitigates injury in term newborns.

Bumetanide enhances phenobarbital efficacy in a rat model of hypoxic neonatal seizures.

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Ryan T Cleary

Full Text Available Neonatal seizures can be refractory to conventional anticonvulsants, and this may in part be due to a developmental increase in expression of the neuronal Na(+-K(+-2 Cl(- cotransporter, NKCC1, and consequent paradoxical excitatory actions of GABAA receptors in the perinatal period. The most common cause of neonatal seizures is hypoxic encephalopathy, and here we show in an established model of neonatal hypoxia-induced seizures that the NKCC1 inhibitor, bumetanide, in combination with phenobarbital is significantly more effective than phenobarbital alone. A sensitive mass spectrometry assay revealed that bumetanide concentrations in serum and brain were dose-dependent, and the expression of NKCC1 protein transiently increased in cortex and hippocampus after hypoxic seizures. Importantly, the low doses of phenobarbital and bumetanide used in the study did not increase constitutive apoptosis, alone or in combination. Perforated patch clamp recordings from ex vivo hippocampal slices removed following seizures revealed that phenobarbital and bumetanide largely reversed seizure-induced changes in EGABA. Taken together, these data provide preclinical support for clinical trials of bumetanide in human neonates at risk for hypoxic encephalopathy and seizures.

Fetal Stress and Programming of Hypoxic/Ischemic-Sensitive Phenotype in the Neonatal Brain: Mechanisms and Possible Interventions

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Li, Yong; Gonzalez, Pablo; Zhang, Lubo

2012-01-01

Growing evidence of epidemiological, clinical and experimental studies has clearly shown a close link between adverse in utero environment and the increased risk of neurological, psychological and psychiatric disorders in later life. Fetal stresses, such as hypoxia, malnutrition, and fetal exposure to nicotine, alcohol, cocaine and glucocorticoids may directly or indirectly act at cellular and molecular levels to alter the brain development and result in programming of heightened brain vulnerability to hypoxic-ischemic encephalopathy and the development of neurological diseases in the postnatal life. The underlying mechanisms are not well understood. However, glucocorticoids may play a crucial role in epigenetic programming of neurological disorders of fetal origins. This review summarizes the recent studies about the effects of fetal stress on the abnormal brain development, focusing on the cellular, molecular and epigenetic mechanisms and highlighting the central effects of glucocorticoids on programming of hypoxicischemic-sensitive phenotype in the neonatal brain, which may enhance the understanding of brain pathophysiology resulting from fetal stress and help explore potential targets of timely diagnosis, prevention and intervention in neonatal hypoxic-ischemic encephalopathy and other for brain disorders. PMID:22627492

Fetal stress and programming of hypoxic/ischemic-sensitive phenotype in the neonatal brain: mechanisms and possible interventions.

Science.gov (United States)

Li, Yong; Gonzalez, Pablo; Zhang, Lubo

2012-08-01

Growing evidence of epidemiological, clinical and experimental studies has clearly shown a close link between adverse in utero environment and the increased risk of neurological, psychological and psychiatric disorders in later life. Fetal stresses, such as hypoxia, malnutrition, and fetal exposure to nicotine, alcohol, cocaine and glucocorticoids may directly or indirectly act at cellular and molecular levels to alter the brain development and result in programming of heightened brain vulnerability to hypoxic-ischemic encephalopathy and the development of neurological diseases in the postnatal life. The underlying mechanisms are not well understood. However, glucocorticoids may play a crucial role in epigenetic programming of neurological disorders of fetal origins. This review summarizes the recent studies about the effects of fetal stress on the abnormal brain development, focusing on the cellular, molecular and epigenetic mechanisms and highlighting the central effects of glucocorticoids on programming of hypoxic-ischemic-sensitive phenotype in the neonatal brain, which may enhance the understanding of brain pathophysiology resulting from fetal stress and help explore potential targets of timely diagnosis, prevention and intervention in neonatal hypoxic-ischemic encephalopathy and other brain disorders. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of neonatal. gamma. -ray irradiation on rat hippocampus: Pt. 1; Postnatal maturation of hippocampal cells

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Represa, A; Dessi, F; Beaudoin, M; Ben-Ari, Y [Institut National de la Sante et de la Recherche Medicale (INSERM), 75 - Paris (France)

1991-01-01

The axons of dentate granule cells, the mossy fibres, establish synaptic contacts with the thorny excrescences of the apical dendrite of CA3 pyramidal neurons. Dentate granule cells develop postnatally in rats, whereas the CA3 pyramidal cells are generated before birth. In the present studies, using unilateral neonatal {gamma}-ray irradiation to destroy the granule cells in one hemisphere, we have studied the effect of mossy fibre deprivation on the development of their targets. We show that such ''degranulation'' prevents the normal development of giant thorny excrescences, suggesting that the development of thorny excrescences in CA3 pyramidal neurons is under the control of mossy fibres. In contrast, irradiation of the hippocampus of the neonatal rat does not affect the development of the dendritic arborization of CA3 pyramidal cells and their non-mossy dendritic spines. (author).

Microwave hyperthermia enhancement of methotrexate absorption in rat brains

International Nuclear Information System (INIS)

Lin, J.C.; Yuen, M.K.; Jung, D.T.

1987-01-01

The author studied enhanced absorption of methotrexate (MTX) in brains of male Wistar (10 weeks old, 500g) subjected to microwave hyperthermia. The rat was anesthetized using 40 mg/kg of sodium pentobarbital, IP and was placed in a stereotaxic head holder. Microwave energy (2450 MHz, 2.6 W/cm/sup 2/, CW) were applied directly to the left side of the rat's head by a coaxial applicator for 20 min. The body temperature was kept at 37.8 0 C. The brain temperature recorded in a similar group of animals using a Vitek probe was about 45 0 C. Three different MTX dosages, 50, 100 and 200 mg/kg, were injected intravenously immediately following microwave irradiation into three groups of rats in 1.5, 3 and 6 min., respectively. MTX was allowed to circulate for five min. before brains were removed for analysis. Standard HPLC procedures were applied to samples from anterior and posterior left hemisphere of the cerebrum, and the cerebellum. Samples from the right hemisphere were used for controls. The average absorption at the posterior left hemisphere was found to be 2.4, 9.6 and 12.4μg of MTX/g of brain tissue for 50, 100 and 200 mg/kg, respectively. These results indicate that MTX absorption is significantly increased in rat brains subjected to microwave hyperthermia treatment

Neuroanatomy-based matrix-guided trimming protocol for the rat brain.

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Defazio, Rossella; Criado, Ana; Zantedeschi, Valentina; Scanziani, Eugenio

2015-02-01

Brain trimming through defined neuroanatomical landmarks is recommended to obtain consistent sections in rat toxicity studies. In this article, we describe a matrix-guided trimming protocol that uses channels to reproduce coronal levels of anatomical landmarks. Both setup phase and validation study were performed on Han Wistar male rats (Crl:WI(Han)), 10-week-old, with bodyweight of 298 ± 29 (SD) g, using a matrix (ASI-Instruments(®), Houston, TX) fitted for brains of rats with 200 to 400 g bodyweight. In the setup phase, we identified eight channels, that is, 6, 8, 10, 12, 14, 16, 19, and 21, matching the recommended landmarks midway to the optic chiasm, frontal pole, optic chiasm, infundibulum, mamillary bodies, midbrain, middle cerebellum, and posterior cerebellum, respectively. In the validation study, we trimmed the immersion-fixed brains of 60 rats using the selected channels to determine how consistently the channels reproduced anatomical landmarks. Percentage of success (i.e., presence of expected targets for each level) ranged from 89 to 100%. Where 100% success was not achieved, it was noted that the shift in brain trimming was toward the caudal pole. In conclusion, we developed and validated a trimming protocol for the rat brain that allow comparable extensiveness, homology, and relevance of coronal sections as the landmark-guided trimming with the advantage of being quickly learned by technicians. © 2014 by The Author(s).

The effect of infectious brain edema on NMDA receptor binding in rat's brain

International Nuclear Information System (INIS)

Cheng Guansheng; Chen Jianfang; Chen Xiang

1997-01-01

PURPOSE: The effect of the infectious brain edema (IBE) induced by Bordetella Pertussis (BP) on the specific binding of 3 H MK-801 in rat's brain in vivo was determined. METHODS: BP was injected via left internal carotid artery in rat model of infectious brain edema. Male SD rats were divided into three groups: 1) Group control (NS, n = 11); 2) Group IBF (BP, n = 12); 3) Group pretreatment of MK-801 + PB (MK-801, n = 4). Normal saline or BP 0.2 ml/kg was injected into left internal carotid artery in NS and BP group respectively. MK-801 0.5 mg/kg per day was injected i.p. two days before injection of BP in group MK-801. Rats were killed by decapitation at 24 hours after injection of BP. The specific binding of N-methyl-D-aspartate (NMDA) receptor were measured with 3 H-MK-801 in the neuronal membrane of cerebral cortex. The Scatchard plots were performed. RESULTS: The B max values were 0.623 +- 0.082 and 0.606 +- 0.087 pmol/mg protein in group NS and BP respectively (t = 0.48, P>0.05). The Kd values were 43.1 +- 4.2 and 30.5 +- 3.0 nmol/L in group NS and BP respectively (t = 7.8, P<0.05). The specific binding of NMDA receptor was decreased by pretreatment of MK-801. CONCLUSIONS: The total number of NMDA receptor had not changed, whereas its affinity increased significantly in the model of brain edema induced by pertussis bacilli in rat. The increase of affinity of NMDA receptor can be blockaded by MK-801 pretreatment in vivo

Neonatal brain hemorrhage (NBH) of prematurity: translational mechanisms of the vascular-neural network.

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Lekic, Tim; Klebe, Damon; Poblete, Roy; Krafft, Paul R; Rolland, William B; Tang, Jiping; Zhang, John H

2015-01-01

Neonatal brain hemorrhage (NBH) of prematurity is an unfortunate consequence of preterm birth. Complications result in shunt dependence and long-term structural changes such as posthemorrhagic hydrocephalus, periventricular leukomalacia, gliosis, and neurological dysfunction. Several animal models are available to study this condition, and many basic mechanisms, etiological factors, and outcome consequences, are becoming understood. NBH is an important clinical condition, of which treatment may potentially circumvent shunt complication, and improve functional recovery (cerebral palsy, and cognitive impairments). This review highlights key pathophysiological findings of the neonatal vascular-neural network in the context of molecular mechanisms targeting the posthemorrhagic hydrocephalus affecting this vulnerable infant population.

Neonatal Brain Hemorrhage (NBH) of Prematurity: Translational Mechanisms of the Vascular-Neural Network

Science.gov (United States)

Lekic, Tim; Klebe, Damon; Poblete, Roy; Krafft, Paul R.; Rolland, William B.; Tang, Jiping; Zhang, John H.

2015-01-01

Neonatal brain hemorrhage (NBH) of prematurity is an unfortunate consequence of preterm birth. Complications result in shunt dependence and long-term structural changes such as post-hemorrhagic hydrocephalus, periventricular leukomalacia, gliosis, and neurological dysfunction. Several animal models are available to study this condition, and many basic mechanisms, etiological factors, and outcome consequences, are becoming understood. NBH is an important clinical condition, of which treatment may potentially circumvent shunt complication, and improve functional recovery (cerebral palsy, and cognitive impairments). This review highlights key pathophysiological findings of the neonatal vascular-neural network in the context of molecular mechanisms targeting the post-hemorrhagic hydrocephalus affecting this vulnerable infant population. PMID:25620100

Decreased α1-adrenergic receptor-mediated inositide hydrolysis in neurons from hypertensive rat brain

International Nuclear Information System (INIS)

Feldstein, J.B.; Gonzales, R.A.; Baker, S.P.; Sumners, C.; Crews, F.T.; Raizada, M.K.

1986-01-01

The expression of α 1 -adrenergic receptors and norepinephrine (NE)-stimulated hydrolysis of inositol phospholipid has been studied in neuronal cultures from the brains of normotensive (Wistar-Kyoto, WKY) and spontaneously hypertensive (SH) rats. Binding of 125 I-1-[β-(4-hydroxyphenyl)-ethyl-aminomethyl] tetralone (HEAT) to neuronal membranes was 68-85% specific and was rapid. Competition-inhibition experiments with various agonists and antagonists suggested that 125 I-HEAT bound selectively to α 1 -adrenergic receptors. Specific binding of 125 I-HEAT to neuronal membranes from SH rat brain cultures was 30-45% higher compared with binding in WKY normotensive controls. This increase was attributed to an increase in the number of α 1 -adrenergic receptors on SH rat brain neurons. Incubation of neuronal cultures of rat brain from both strains with NE resulted in a concentration-dependent stimulation of release of inositol phosphates, although neurons from SH rat brains were 40% less responsive compared with WKY controls. The decrease in responsiveness of SH rat brain neurons to NE, even though the α 1 -adrenergic receptors are increased, does not appear to be due to a general defect in membrane receptors and postreceptor signal transduction mechanisms. This is because neither the number of muscarinic-cholinergic receptors nor the carbachol-stimulated release of inositol phosphates is different in neuronal cultures from the brains of SH rats compared with neuronal cultures from the brains of WKY rats. These observations suggest that the increased expression of α 1 -adrenergic receptors does not parallel the receptor-mediated inositol phosphate hydrolysis in neuronal cultures from SH rat brain

Evaluation of neonatal brain myelination using the T1- and T2-weighted MRI ratio.

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Soun, Jennifer E; Liu, Michael Z; Cauley, Keith A; Grinband, Jack

2017-09-01

To validate the T1- and T2-weighted (T1w/T2w) MRI ratio technique in evaluating myelin in the neonatal brain. T1w and T2w MR images of 10 term neonates with normal-appearing brain parenchyma were obtained from a single 1.5 Tesla MRI and retrospectively analyzed. T1w/T2w ratio images were created with a postprocessing pipeline and qualitatively compared with standard clinical sequences (T1w, T2w, and apparent diffusion coefficient [ADC]). Quantitative assessment was also performed to assess the ratio technique in detecting areas of known myelination (e.g., posterior limb of the internal capsule) and very low myelination (e.g., optic radiations) using linear regression analysis and the Michelson Contrast equation, a measure of luminance contrast intensity. The ratio image provided qualitative improvements in the ability to visualize regional variation in myelin content of neonates. Linear regression analysis demonstrated a significant inverse relationship between the ratio intensity values and ADC values in the posterior limb of the internal capsule and the optic radiations (R 2  = 0.96 and P ratio images were 1.6 times higher than T1w, 2.6 times higher than T2w, and 1.8 times higher than ADC (all P ratio improved visualization of the corticospinal tract, one of the earliest myelinated pathways. The T1w/T2w ratio accentuates contrast between myelinated and less myelinated structures and may enhance our diagnostic ability to detect myelination patterns in the neonatal brain. 2 Technical Efficacy: Stage2 J. MAGN. RESON. IMAGING 2017;46:690-696. © 2016 International Society for Magnetic Resonance in Medicine.

Effects of sleeve gastrectomy in neonatally streptozotocin-induced diabetic rats.

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Yan Wang

Full Text Available BACKGROUND: Sleeve gastrectomy (SG has emerged recently as a stand-alone bariatric procedure to treat morbid obesity and enhance glucose homeostasis. The aim of the study was to evaluate its effects in neonatally streptozotocin (STZ-induced diabetic rats (n-STZ diabetic rats. METHODOLOGY AND PRINCIPAL FINDINGS: To induce diabetes, STZ (90 mg/kg was administered intraperitoneally to 2-day-old male pups. When 12 weeks old, diabetic rats were randomized into sleeve operation group (SLG, n = 6 and sham operation group (SOG, n = 6. Body weights were monitored weekly, and daily consumption of water and food were followed for eight consecutive weeks postoperatively. Serum glucose levels were measured periodically at the 4th and 8th week after surgery. Insulin, ghrelin, glucose-dependent insulinotropic polypeptide (GIP and Glucagon-like peptide-1 (GLP-1 levels were assayed at the end of the study. Our data showed that SLG rats exhibited significantly lower body weight gain in addition to reduced food and water intakes postoperatively compared to their sham-operation counterparts. However, resolution of diabetes was not observed in our study. Correspondingly, there were no significant differences between SOG rats and SLG rats in glucose metabolism-associated hormones, including insulin, GIP and GLP-1. In contrast, ghrelin level significantly decreased (P<0.01 in SLG group (58.01 ± 3.75 pg/ml after SG surgery compared to SOG group (76.36 ± 3.51 pg/ml. CONCLUSIONS: These observations strongly suggest that SG is effective in controlling body weight. However, SG did not achieve resolution or improvement of diabetes in n-STZ diabetic rats.

Stereological brain volume changes in post-weaned socially isolated rats

DEFF Research Database (Denmark)

Fabricius, Katrine; Helboe, Lone; Steiniger-Brach, Björn

2010-01-01

Rearing rats in isolation after weaning is an environmental manipulation that leads to behavioural and neurochemical alterations that resemble what is seen in schizophrenia. The model is neurodevelopmental in origin and has been used as an animal model of schizophrenia. However, only a few studies...... Lister Hooded rats isolated from postnatal day 25 for 15 weeks. We observed the expected gender differences in total brain volume with males having larger brains than females. Further, we found that isolated males had significantly smaller brains than group-housed controls and larger lateral ventricles...... than controls. However, this was not seen in female rats. Isolated males had a significant smaller hippocampus, dentate gyrus and CA2/3 where isolated females had a significant smaller CA1 compared to controls. Thus, our results indicate that long-term isolation of male rats leads to neuroanatomical...

Studies on estradiol-2/4-hydroxylase activity in rat brain and liver

International Nuclear Information System (INIS)

Theron, C.N.

1985-03-01

A sensitive and specific radio-enzymatic assay was used to study estradiol-2/4-hydroxylase activity in rat liver microsomes and in microsomes obtained from 6 discrete brain areas of the rat. Kinetic parameters were determined for these enzyme activities. The effects of different P-450 inhibitors on estradiol-2/4-hydroxylase activity in brain and liver microsomes were also studied. In both organs these enzyme activities were found to be located mainly in the microsomal fraction and were inhibited by the 3 P-450 inhibitors tested. The hepatic estradiol-2/4-hydroxylase activity in adult male rats was significantly higher than that of females, but the enzyme activity in the brain did not exhibit a similar sex difference. Furthermore, estradiol-2/4-hydroxylase activity in rat liver was strongly induced by phenobarbitone treatment, but not in the brain. The phenobarbitone-induced activity in male and female rats exhibited significant kinetic differences. In female rats sexual maturation was associated with significant changes in the apparent Km of estradiol-2/4-hydroxylases in the liver and hypothalamus. Evidence was found that the in vitro estradiol-2/4-hydroxylase activity in rat brain and liver is due to more than one form of microsomal P-450. Kinetic studies showed important differences between the estradiol-2/4-hydroxylase activities in the hippocampus and hypothalamus. Significant differences in estradiol-2/4-hydroxylase activities were observed in the 6 brain areas studied, with the hippocampus showing the highest, and the hypothalamus the lowest activity at all developmental stages in both male and female rats

Paracetamol (acetaminophen) administration during neonatal brain development affects cognitive function and alters its analgesic and anxiolytic response in adult male mice.

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Viberg, Henrik; Eriksson, Per; Gordh, Torsten; Fredriksson, Anders

2014-03-01

Paracetamol (acetaminophen) is one of the most commonly used drugs for the treatment of pain and fever in children, both at home and in the clinic, and is now also found in the environment. Paracetamol is known to act on the endocannabinoid system, involved in normal development of the brain. We examined if neonatal paracetamol exposure could affect the development of the brain, manifested as adult behavior and cognitive deficits, as well as changes in the response to paracetamol. Ten-day-old mice were administered a single dose of paracetamol (30 mg/kg body weight) or repeated doses of paracetamol (30 + 30 mg/kg body weight, 4h apart). Concentrations of paracetamol and brain-derived neurotrophic factor (BDNF) were measured in the neonatal brain, and behavioral testing was done when animals reached adulthood. This study shows that acute neonatal exposure to paracetamol (2 × 30 mg) results in altered locomotor activity on exposure to a novel home cage arena and a failure to acquire spatial learning in adulthood, without affecting thermal nociceptive responding or anxiety-related behavior. However, mice neonatally exposed to paracetamol (2 × 30 mg) fail to exhibit paracetamol-induced antinociceptive and anxiogenic-like behavior in adulthood. Behavioral alterations in adulthood may, in part, be due to paracetamol-induced changes in BDNF levels in key brain regions at a critical time during development. This indicates that exposure to and presence of paracetamol during a critical period of brain development can induce long-lasting effects on cognitive function and alter the adult response to paracetamol in mice.

Stereological brain volume changes in post-weaned socially isolated rats

DEFF Research Database (Denmark)

Fabricius, Katrine; Helboe, Lone; Steiniger-Brach, Björn

2010-01-01

Lister Hooded rats isolated from postnatal day 25 for 15 weeks. We observed the expected gender differences in total brain volume with males having larger brains than females. Further, we found that isolated males had significantly smaller brains than group-housed controls and larger lateral ventricles...... have evaluated the neuroanatomical changes in this animal model in comparison to changes seen in schizophrenia. In this study, we applied stereological volume estimates to evaluate the total brain, the ventricular system, and the pyramidal and granular cell layers of the hippocampus in male and female...... than controls. However, this was not seen in female rats. Isolated males had a significant smaller hippocampus, dentate gyrus and CA2/3 where isolated females had a significant smaller CA1 compared to controls. Thus, our results indicate that long-term isolation of male rats leads to neuroanatomical...

Transfer of milk prolactin ro the plasma of neonatal rats by intestinal absorption

Energy Technology Data Exchange (ETDEWEB)

Whitworth, N S; Grosvenor, C E [Tennessee Univ., Memphis (USA). Dept. of Physiology and Biophysics

1978-11-01

Prolactin passes from the systemic circulation of lactating rats into the milk where it can be consumed by the young rats during suckling. /sup 131/- labelled rat prolactin was detected in the plasma of 9- to 14-day-old rats after being nursed by mothers previously injected with /sup 131/I-labelled rat prolactin and after the pups had received /sup 131/I-labelled rat prolactin by gastric intubation. It was estimated that 16% of the /sup 131/I-labelled rat prolactin given by gastric intubation subsequently appeared in the plasma of the neonate. Gastric administration of 10.5 or 21.0 ..mu..g B-1 rat prolactin significantly raised the level of prolactin in the plasma of 13-day-old pups, but a similar increase was not observed when 27-day-old rats were given 46.2 ..mu..g B-1 prolactin by gastric intubation. The concentration of prolactin in the plasma of 13-to 14-day-old rats rose to 55 ng/ml 30 min after the onset of nursing by mothers whose mammary glands were full of milk, whereas the concentration in the plasma of mothers with empty mammary glands remained at basal values. It is concluded that the intestine of the newborn is permeable to prolactin and that milk may constitute an exogeneous source of prolactin for the suckled offspring.

Increased Oxidative Stress and Mitochondrial Dysfunction in Zucker Diabetic Rat Liver and Brain

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Haider Raza

2015-02-01

Full Text Available Background/Aims: The Zucker diabetic fatty (ZDF, FA/FA rat is a genetic model of type 2 diabetes, characterized by insulin resistance with progressive metabolic syndrome. We have previously demonstrated mitochondrial dysfunction and oxidative stress in the heart, kidneys and pancreas of ZDF rats. However, the precise molecular mechanism of disease progression is not clear. Our aim in the present study was to investigate oxidative stress and mitochondrial dysfunction in the liver and brain of ZDF rats. Methods: In this study, we have measured mitochondrial oxidative stress, bioenergetics and redox homeostasis in the liver and brain of ZDF rats. Results: Our results showed increased reactive oxygen species (ROS production in the ZDF rat brain compared to the liver, while nitric oxide (NO production was markedly increased both in the brain and liver. High levels of lipid and protein peroxidation were also observed in these tissues. Glutathione metabolism and mitochondrial respiratory functions were adversely affected in ZDF rats when compared to Zucker lean (ZL, +/FA control rats. Reduced ATP synthesis was also observed in the liver and brain of ZDF rats. Western blot analysis confirmed altered expression of cytochrome P450 2E1, iNOS, p-JNK, and IκB-a confirming an increase in oxidative and metabolic stress in ZDF rat tissues. Conclusions: Our data shows that, like other tissues, ZDF rat liver and brain develop complications associated with redox homeostasis and mitochondrial dysfunction. These results, thus, might have implications in understanding the etiology and pathophysiology of diabesity which in turn, would help in managing the disease associated complications.

[Lessening effect of hypoxia-preconditioned rat cerebrospinal fluid on oxygen-glucose deprivation-induced injury of cultured hippocampal neurons in neonate rats and possible mechanism].

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Niu, Jing-Zhong; Zhang, Yan-Bo; Li, Mei-Yi; Liu, Li-Li

2011-12-25

The present study was to investigate the effect of cerebrospinal fluid (CSF) from the rats with hypoxic preconditioning (HPC) on apoptosis of cultured hippocampal neurons in neonate rats under oxygen glucose deprivation (OGD). Adult Wistar rats were exposed to 3 h of hypoxia for HPC, and then their CSF was taken out. Cultured hippocampal neurons from the neonate rats were randomly divided into four groups (n = 6): normal control group, OGD group, normal CSF group and HPC CSF group. OGD group received 1.5 h of incubation in glucose-free Earle's solution containing 1 mmol/L Na2S2O4, and normal and HPC CSF groups were subjected to 1 d of corresponding CSF treatments followed by 1.5 h OGD. The apoptosis of neurons was analyzed by confocal laser scanning microscope and flow cytometry using Annexin V/PI double staining. Moreover, protein expressions of Bcl-2 and Bax were detected by immunofluorescence. The results showed that few apoptotic cells were observed in normal control group, whereas the number of apoptotic cells was greatly increased in OGD group. Both normal and HPC CSF could decrease the apoptosis of cultured hippocampal neurons injured by OGD (P neurons by up-regulating expression of Bcl-2 and down-regulating expression of Bax.

Effects of neonatal pain, stress and their interrelation on pain sensitivity in later life in male rats.

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Butkevich, Irina P; Mikhailenko, Viktor A; Vershinina, Elena A; Aloisi, Anna Maria

2016-08-31

Neonatal pain and stress induce long-term changes in pain sensitivity. Therefore their interrelation is a topical subject of clinical and basic research. The present study investigated the effects of inflammatory peripheral pain and stress of maternal deprivation (MD)-isolation in 1-2- and 7-8-day-old Wistar rats (P1,2 and P7,8 respectively, ages comparable to preterm and full-term human babies) on basal pain and pain sensitivity in conditions of inflammatory pain (formalin test) during adolescence. The neonatal impacts were: pain (formalin injection, FOR in the paw), stress (a short 60-min MD), or pain+stress combination (FOR+MD), and appropriate controls. We found that stress of short-term maternal deprivation-isolation and inflammatory pain on P1,2 and P7,8 significantly increased the vulnerability of the nociceptive system to inflammatory pain. Maternal deprivation-isolation on P1,2 as compared with a similar impact on P7,8 had a greater effect on pain sensitivity of the adolescent rats, but the influence of early pain was independent of the injury age. Only adolescent rats with an early combination of pain and maternal deprivation-isolation showed hypoalgesia in the hot plate (HP) test. However licking duration (reflecting pain sensitivity) in these rats did not exceed licking duration in animals exposed only to maternal deprivation-isolation or pain. This study adds new data to the growing body of work demonstrating that early noxious impacts have long-term consequences for the functional activity of the nociceptive system. Our new findings may help to understand the impact of pain and maternal separation in the neonatal intensive care unit.

Hypoxia-ischemia or excitotoxin-induced tissue plasminogen activator- dependent gelatinase activation in mice neonate brain microvessels.

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Priscilla L Omouendze

Full Text Available Hypoxia-ischemia (HI and excitotoxicity are validated causes of neonatal brain injuries and tissue plasminogen activator (t-PA participates in the processes through proteolytic and receptor-mediated pathways. Brain microvascular endothelial cells from neonates in culture, contain and release more t-PA and gelatinases upon glutamate challenge than adult cells. We have studied t-PA to gelatinase (MMP-2 and MMP-9 activity links in HI and excitotoxicity lesion models in 5 day-old pups in wild type and in t-PA or its inhibitor (PAI-1 genes inactivated mice. Gelatinolytic activities were detected in SDS-PAGE zymograms and by in situ fluorescent DQ-gelatin microscopic zymographies. HI was achieved by unilateral carotid ligature followed by a 40 min hypoxia (8%O₂. Excitotoxic lesions were produced by intra parenchymal cortical (i.c. injections of 10 µg ibotenate (Ibo. Gel zymograms in WT cortex revealed progressive extinction of MMP-2 and MMP-9 activities near day 15 or day 8 respectively. MMP-2 expression was the same in all strains while MMP-9 activity was barely detectable in t-PA⁻/⁻ and enhanced in PAI-1⁻/⁻ mice. HI or Ibo produced activation of MMP-2 activities 6 hours post-insult, in cortices of WT mice but not in t-PA⁻/⁻ mice. In PAI-1⁻/⁻ mice, HI or vehicle i.c. injection increased MMP-2 and MMP-9 activities. In situ zymograms using DQ-gelatin revealed vessel associated gelatinolytic activity in lesioned areas in PAI-1⁻/⁻ and in WT mice. In WT brain slices incubated ex vivo, glutamate (200 µM induced DQ-gelatin activation in vessels. The effect was not detected in t-PA⁻/⁻ mice, but was restored by concomitant exposure to recombinant t-PA (20 µg/mL. In summary, neonatal brain lesion paradigms and ex vivo excitotoxic glutamate evoked t-PA-dependent gelatinases activation in vessels. Both MMP-2 and MMP-9 activities appeared t-PA-dependent. The data suggest that vascular directed protease inhibition may have

Studies of aluminum in rat brain

Energy Technology Data Exchange (ETDEWEB)

Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

1985-01-01

The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

Studies of aluminum in rat brain

International Nuclear Information System (INIS)

Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

1985-01-01

The effects of high aluminum concentrations in rat brains were studied using 14 C autoradiography to measure the uptake of 14 C 2-deoxy-D-glucose ( 14 C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-μm resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The 14 C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of 14 C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10 9 Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab

Brain biochemistry of infant mice and rats exposed to lead

Energy Technology Data Exchange (ETDEWEB)

Berber, G.B.; Maes, J.; Gilliavod, N.; Casale, G.

1978-05-01

Brains of rats and mice exposed to lead from birth receive biochemical examinations. Mice are given drinking water with lead and are studied until they are 17 days old. Rats ae given lead in the diet and followed for more than a year. In mice a retardation in body growth and development in brain DNA is found. In rats, cathepsin is enhanced at almost all times. An important role of proteolytic processes and biogenic animes is suggested in lead encephalopathy. (33 references, 7 tables)

Risperidone treatment increases CB1 receptor binding in rat brain

DEFF Research Database (Denmark)

Secher, Anna; Husum, Henriette; Holst, Birgitte

2010-01-01

, the ghrelin receptor, neuropeptide Y, adiponectin and proopiomelanocortin. We investigated whether the expression of these factors was affected in rats chronically treated with the antipsychotic risperidone. METHODS: Male Sprague-Dawley rats were treated with risperidone (1.0 mg/kg/day) or vehicle (20...... showed that risperidone treatment altered CB(1) receptor binding in the rat brain. Risperidone-induced adiposity and metabolic dysfunction in the clinic may be explained by increased CB(1) receptor density in brain regions involved in appetite and regulation of metabolic function....

Effect of ketamine on aquaporin-4 expression and neuronal apoptosis in brain tissues following brain injury in rats

Institute of Scientific and Technical Information of China (English)

Zangong Zhou; Xiangyu Ji; Li Song; Jianfang Song; Shiduan Wang; Yanwei Yin

2006-01-01

BACKGROUND: Aquaporin-4 (AQP-4) is closely related to the formation of brain edema. Neuronal apoptosis plays an important part in the conversion of swelled neuron following traumatic brain injury. At present, the studies on the protective effect of ketamine on brain have involved in its effect on aquaporin-4 expression and neuronal apoptosis in the brain tissues following brain injury in rats.OBJECTIVE: To observe the effect of ketamine on AQP-4 expression and neuronal apoptosis in the brain tissue following rat brain injury, and analyze the time-dependence of ketamine in the treatment of brain injury.DESIGN: Randomized grouping design, controlled animal trial.SETTING: Department of Anesthesiology, the Medical School Hospital of Qingdao University.MATERIALS: Totally 150 rats of clean grade, aged 3 months, were involved and randomized into control group and ketamine-treated group, with 75 rats in each. Each group was divided into 5 subgroups separately at 6,12, 24, 48 and 72 hours after injury, with 15 rats at each time point. Main instruments and reagents:homemade beat machine, ketamine hydrochloride (Hengrui Pharmaceutical Factory, Jiangsu), rabbit anti-rat AQP-4 polyclonal antibody, SABC immunohistochemical reagent kit and TUNEL reagent kit (Boster Co.,Ltd.,Wuhan).METHODS: This trial was carried out in the Institute of Cerebrovascular Disease, Medical College of Qingdao University during March 2005 to February 2006. A weight-dropping rat model of brain injury was created with Feeney method. The rats in the ketamine-treated group were intraperitoneally administered with 50 g/L ketamine (120 mg/kg) one hour after injury, but ketamine was replaced by normal saline in the control group. In each subgroup, the water content of cerebral hemisphere was measured in 5 rats chosen randomly. The left 10 rats in each subgroup were transcardiacally perfused with ketamine, then the brain tissue was made into paraffin sections and stained by haematoxylin and eosin. Neuronal

Sestrin2 induced by hypoxia inducible factor1 alpha protects the blood-brain barrier via inhibiting VEGF after severe hypoxic-ischemic injury in neonatal rats.

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Shi, Xudan; Doycheva, Desislava Met; Xu, Liang; Tang, Jiping; Yan, Min; Zhang, John H

2016-11-01

Hypoxic ischemic (HI) encephalopathy remains the leading cause of perinatal brain injury resulting in long term disabilities. Stabilization of blood brain barrier (BBB) after HI is an important target, therefore, in this study we aim to determine the role of sestrin2, a stress inducible protein which is elevated after various insults, on BBB stabilization after moderate and severe HI injuries. Rat pups underwent common carotid artery ligation followed by either 150min (severe model) or 100min (moderate model) of hypoxia. 1h post HI, rats were intranasally administered with recombinant human sestrin2 (rh-sestrin2) and sacrificed for infarct area, brain water content, righting reflex and geotaxis reflex. Sestrin2 was silenced using siRNA and an activator/inhibitor of hypoxia inducible factor1α (HIF1α) was used to examine their roles on BBB permeability. Rats subjected to severe HI exhibited larger infarct area and higher sestrin2 expression compared to rats in the moderate HI group. rh-sestrin2 attenuated brain infarct and edema, while silencing sestrin2 reversed these protective effects after severe HI. HIF1α induced sestrin2 activation in severe HI but not in moderate HI groups. A HIF1a agonist was shown to increase permeability of the BBB via vascular endothelial growth factor (VEGF) after moderate HI. However, after severe HI, HIF1α activated both VEGF and sestrin2. But HIF1α dependent sestrin2 activation was the predominant pathway after severe HI which inhibited VEGF and attenuated BBB permeability. rh-sestrin2 attenuated BBB permeability via upregulation of endogenous sestrin2 which was induced by HIF1α after severe HI. However, HIF1α's effects as a prodeath or prosurvival signal were influenced by the severity of HI injury. Copyright © 2016 Elsevier Inc. All rights reserved.

Nitrous oxide discretely up-regulates nNOS and p53 in neonatal rat brain.

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Cattano, D; Valleggi, S; Abramo, A; Forfori, F; Maze, M; Giunta, F

2010-06-01

Animal studies suggest that neuronal cell death often results from anesthetic administration during synaptogenesis. Volatile anesthetics are strongly involved in triggering neuronal apoptosis, whereas other inhalational agents (xenon) demonstrate protective effects. Nitrous oxide (N2O) has modest pro-apoptotic effects on its own and potent, synergistic toxic effects when combined with volatile agents. Recent findings suggest that, during periods of rapid brain development, the enhanced neurodegeneration triggered by anesthetic drugs may be caused by a compensatory increase in intracellular free calcium, a potent activator of neuronal nitric oxide synthase (nNOS). Anesthesia-induced neuro-apoptosis is also activated via the intrinsic and the extrinsic apoptotic pathways because both pathways involve p53, a key regulatory gene. The molecular events related to neuronal cell apoptosis are not completely understood. To gain further insight into the events underlying neuro-apoptosis, we analyzed the transcriptional consequences of N2O exposure on nNOS, iNOS and p53 mRNA levels. The study used 2 groups of postnatal day seven Sprague/Dawley rats (N=6 each) that were exposed for 120 minutes to air (75% N2, 25% O2) or N2O (75% N2O, 25% O2; this N2O concentration is commonly used to induce anesthesia and has been demonstrated to trigger neurodegeneration in postnatal day seven rats). Total RNA was isolated from each brain and expression analyses on iNOS and nNOS transcripts were performed using relative Real-Time C-reactive protein PCR (using G3PDH as a housekeeping gene). A semi-quantitative RT-PCR analysis was performed on the p53 transcript (using Ciclophylin A as a housekeeping gene). Statistical analysis (REST 2005) revealed a significant, 11-fold up-regulation (P=0.026) of the nNOS transcript but no significant changes in iNOS transcription. The p53 mRNA was up-regulated almost 2-fold (P=0.0002; Student's t-Test; GraphPad Prism 4.00) in N2O-treated samples relative to

Inflammation and oxidative stress biomarkers in neonatal brain hypoxia and prediction of adverse neurological outcome: a review

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Marianna Varsami

2013-06-01

Full Text Available Despite advances in perinatal care, the outcome of newborns with hypoxic-ischemic encephalopathy is poor and the issue still remains challenging in neonatology. The use of an easily approachable and practical biomarker not only could identify neonates with severe brain damage and subsequent adverse outcome, but could also target the group of infants that would benefit from a neuroprotective intervention. Recent studies have suggested interleukin-1b, interleukin-6, tumour necrosis alpha (TNF-a and neuron specific enolase (NSE to be potential biomarkers of brain damage in asphyxiated newborns. S100B, lactate dehydrogenase, nitrated albumin-nitrotyrosine, adrenomedullin, activin-A, non protein bound iron, isoprostanes, vascular endothelial growth factor and metalloproteinases have also been proposed by single-centre studies to play a similar role in the field. With this review we aim to provide an overview of existing data in the literature regarding biomarkers for neonatal brain damage.

Intracranial complications of Serratia marcescens infection in neonates.

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Madide, Ayanda; Smith, Johan

2016-03-15

Even though Serratia marcescens is not one of the most common causes of infection in neonates, it is associated with grave morbidity and mortality. We describe the evolution of brain parenchymal affectation observed in association with S. marcescens infection in neonates. This retrospective case series details brain ultrasound findings of five neonates with hospital-acquired S. marcescens infection. Neonatal S. marcescens infection with or without associated meningitis can be complicated by brain parenchymal affectation, leading to cerebral abscess formation. It is recommended that all neonates with this infection should undergo neuro-imaging more than once before discharge from hospital; this can be achieved using bedside ultrasonography.

Intracarotid injection of 195mPt-CDDP on rat brain tumors

International Nuclear Information System (INIS)

Ikawa, Eishi; Kamitani, Hideki; Hori, Tomokatsu; Akaboshi, Mitsuhiko.

1995-01-01

We began to try intracarotid injection of 195m Pt-CDDP on transplanted rats of C6 glioma. As a control, normal rats were also treated with intracarotid injection of 195m Pt-CDDP. After injection, the tumor, the normal brain of injected site, the brain of contralateral site, and the blood were sampled for the measurement of the Pt uptake. On normal rats, the ratio of the Pt uptake of the brain to that of the blood was highest in 20 minutes after injection. The ratio of the Pt uptake of the brain of injected site to that of the blood was almost same as that of the brain of contralateral site, so it seemed that the Pt uptake was not so enhanced with intracarotid injection on the normal brain. On the other hand, the ratio of the Pt uptake of the transplanted brain tumor to that of the blood was greatly higher than that of the normal brain. So it seemed that the intracarotid injection of CDDP may have some activities against brain tumors. This study was now started, so we continue this study further more. (author)

Brain Biomarkers of Long-Term Outcome of Neonatal Onset Urea Cycle Disorder

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Maha Mourad

2016-11-01

Full Text Available Urea cycle disorders (UCDs are common inborn errors of metabolism, with an incidence of one in 30,000 births. They are caused by deficiencies in any of six enzymes and two carrier proteins, the most common being Ornithine Transcarbamylase Deficiency (OTCD. OTCD results in impairment to excrete nitrogen, causing toxic buildup of ammonia with resultant encephalopathy. Hyperammonemia (HA induces the conversion of glutamate to glutamine in the brain. Excess glutamine in the brain causes osmotic changes, cerebral edema, changes in astrocyte morphology, and cell death. Acute symptoms of HA include vomiting, hyperventilation, seizures, and irritability. Long-term neurological effects include deficits in working memory and executive function. To date, there are no predictors of prognosis of infants with neonatal onset OTCD outside of the plasma ammonia level at presentation and duration of a hyperammonemic coma. We provide a comprehensive analysis of a 16-year-old male with neonatal onset of OTCD as an example of how brain biomarkers may be useful to monitor disease course and outcome. This male presented at 8 days of life with plasma ammonia and glutamine of 677 and 4024 micromol/L respectively, and was found to have a missense mutation in Exon 4 (p. R129H. Treatment included protein restriction, sodium benzoate, and citrulline, arginine, and iron. Despite compliance, he suffered recurrent acute hyperammonemic episodes triggered by infections or catabolic stressors. We discuss the long-term effects of the hyperammonemic episodes by following MRI-based disease biomarkers.

In vitro study of acetylcholine and histamine induced contractions in colon and rectum of adult and neonate rats.

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Singh, Shuchita; Mandal, Maloy B

2013-01-01

Contractile mechanisms of different parts of the gut in adult and neonate may not be identical due to developmental processes. The present study was undertaken to investigate acetylcholine (ACh) and histamine induced contractile responses of colon and rectum in adult and neonatal albino rats. Contractile responses were recorded from isolated in vitro preparations. The dose-response curve for ACh (0.001-100 microM) revealed dose dependent increase in contractile responses. A significantly (P pheniramine (100 microM) in adult rectum. This potentiating response of pheniramine was absent in neonate rectum. Such effect was also not seen in colon of both adult and neonate. The present investigation indicates that the contractile responses induced by ACh are similar in both adult and neonate, excepting that the blocking effect of atropine in colon was more pronounced in adult as compared to neonate. Further, the results also indicated different mechanism of histamine action in adults and neonates as evidenced by the significant enhancement of contractions by pheniramine only in adult rectum. Therefore, the present results indicate the existence of a different cholinergic and histaminergic activity in adult and neonate as well as in rectal and colonic tissue.

Neonatal physiological correlates of near-term brain development on MRI and DTI in very-low-birth-weight preterm infants.

Science.gov (United States)

Rose, Jessica; Vassar, Rachel; Cahill-Rowley, Katelyn; Stecher Guzman, Ximena; Hintz, Susan R; Stevenson, David K; Barnea-Goraly, Naama

2014-01-01

Structural brain abnormalities identified at near-term age have been recognized as potential predictors of neurodevelopment in children born preterm. The aim of this study was to examine the relationship between neonatal physiological risk factors and early brain structure in very-low-birth-weight (VLBW) preterm infants using structural MRI and diffusion tensor imaging (DTI) at near-term age. Structural brain MRI, diffusion-weighted scans, and neonatal physiological risk factors were analyzed in a cross-sectional sample of 102 VLBW preterm infants (BW ≤ 1500 g, gestational age (GA) ≤ 32 weeks), who were admitted to the Lucile Packard Children's Hospital, Stanford NICU and recruited to participate prior to routine near-term brain MRI conducted at 36.6 ± 1.8 weeks postmenstrual age (PMA) from 2010 to 2011; 66/102 also underwent a diffusion-weighted scan. Brain abnormalities were assessed qualitatively on structural MRI, and white matter (WM) microstructure was analyzed quantitatively on DTI in six subcortical regions defined by DiffeoMap neonatal brain atlas. Specific regions of interest included the genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, the thalamus, and the globus pallidus. Regional fractional anisotropy (FA) and mean diffusivity (MD) were calculated using DTI data and examined in relation to neonatal physiological risk factors including gestational age (GA), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), and sepsis, as well as serum levels of C-reactive protein (CRP), glucose, albumin, and total bilirubin. Brain abnormalities were observed on structural MRI in 38/102 infants including 35% of females and 40% of males. Infants with brain abnormalities observed on MRI had higher incidence of BPD (42% vs. 25%) and sepsis (21% vs. 6%) and higher mean and peak serum CRP levels, respectively, (0.64 vs. 0.34 mg/dL, p = .008; 1.57 vs. 0.67�

Sex differences in behavioral outcome following neonatal hypoxia ischemia: insights from a clinical meta-analysis and a rodent model of induced hypoxic ischemic brain injury.

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Smith, Amanda L; Alexander, Michelle; Rosenkrantz, Ted S; Sadek, Mona Lisa; Fitch, R Holly

2014-04-01

Hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) is one of the most common injuries among preterm infants and term infants with birth complications. Both populations show cognitive/behavioral deficits, including impairments in sensory, learning/memory, and attention domains. Clinical data suggests a sex difference in HI outcomes, with males exhibiting more severe cognitive/behavioral deficits relative to matched females. Our laboratory has also reported more severe behavioral deficits among male rats with induced HI relative to females with comparable injury (Hill et al., 2011a,b). The current study initially examined published clinical studies from the past 20years where long-term IQ outcome scores for matched groups of male and female premature infants were reported separately (IQ being the most common outcome measure). A meta-analysis revealed a female "advantage," as indicated by significantly better scores on performance and full scale IQ (but not verbal IQ) for premature females. We then utilized a rodent model of neonatal HI injury to assess sham and postnatal day 7 (P7) HI male and female rats on a battery of behavioral tasks. Results showed expected deficits in HI male rats, but also showed task-dependent sex differences, with HI males having significantly larger deficits than HI females on some tasks but equivalent deficits on other tasks. In contrast to behavioral results, post mortem neuropathology associated with HI was comparable across sex. These findings suggest: 1) neonatal female "protection" in some behavioral domains, as indexed by superior outcome following early injury relative to males; and 2) female protection may entail sex-specific plasticity or compensation, rather than a reduction in gross neuropathology. Further exploration of the mechanisms underlying this sex effect could aid in neuroprotection efforts for at-risk neonates in general, and males in particular. Moreover, our current report of comparable anatomical

Correlation between subacute sensorimotor deficits and brain water content after surgical brain injury in rats.

Science.gov (United States)

McBride, Devin W; Wang, Yuechun; Sherchan, Prativa; Tang, Jiping; Zhang, John H

2015-09-01

Brain edema is a major contributor to poor outcome and reduced quality of life after surgical brain injury (SBI). Although SBI pathophysiology is well-known, the correlation between cerebral edema and neurological deficits has not been thoroughly examined in the rat model of SBI. Thus, the purpose of this study was to determine the correlation between brain edema and deficits in standard sensorimotor neurobehavior tests for rats subjected to SBI. Sixty male Sprague-Dawley rats were subjected to either sham surgery or surgical brain injury via partial frontal lobectomy. All animals were tested for neurological deficits 24 post-SBI and fourteen were also tested 72 h after surgery using seven common behavior tests: modified Garcia neuroscore (Neuroscore), beam walking, corner turn test, forelimb placement test, adhesive removal test, beam balance test, and foot fault test. After assessing the functional outcome, animals were euthanized for brain water content measurement. Surgical brain injury resulted in significantly elevated frontal lobe brain water content 24 and 72 h after surgery compared to that of sham animals. In all behavior tests, significance was observed between sham and SBI animals. However, a correlation between brain water content and functional outcome was observed for all tests except Neuroscore. The selection of behavior tests is critical to determine the effectiveness of therapeutics. Based on this study's results, we recommend using beam walking, the corner turn test, the beam balance test, and the foot fault test since correlations with brain water content were observed at both 24 and 72 h post-SBI. Copyright © 2015 Elsevier B.V. All rights reserved.

Correlation between subacute sensorimotor deficits and brain water content after surgical brain injury in rats

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McBride, Devin W.; Wang, Yuechun; Sherchan, Prativa; Tang, Jiping; Zhang, John H.

2015-01-01

Brain edema is a major contributor to poor outcome and reduced quality of life after surgical brain injury (SBI). Although SBI pathophysiology is well-known, the correlation between cerebral edema and neurological deficits has not been thoroughly examined in the rat model of SBI. Thus, the purpose of this study was to determine the correlation between brain edema and deficits in standard sensorimotor neurobehavior tests for rats subjected to SBI. Sixty male Sprague-Dawley rats were subjected to either sham surgery or surgical brain injury via partial frontal lobectomy. All animals were tested for neurological deficits 24 post-SBI and fourteen were also tested 72 hours after surgery using seven common behavior tests: modified Garcia neuroscore (Neuroscore), beam walking, corner turn test, forelimb placement test, adhesive removal test, beam balance test, and foot fault test. After assessing the functional outcome, animals were euthanized for brain water content measurement. Surgical brain injury resulted in a significantly elevated frontal lobe brain water content 24 and 72 hours after surgery compared to that of sham animals. In all behavior tests, significance was observed between sham and SBI animals. However, a correlation between brain water content and functional outcome was observed for all tests except Neuroscore. The selection of behavior tests is critical to determine the effectiveness of therapeutics. Based on this study’s results, we recommend using beam walking, the corner turn test, the beam balance test, and the foot fault test since correlations with brain water content were observed at both 24 and 72 hours post-SBI. PMID:25975171

Radiation therapy of 9L rat brain tumors

International Nuclear Information System (INIS)

Henderson, S.D.; Kimler, B.F.; Morantz, R.A.

1981-01-01

The effects of radiation therapy on normal rats and on rats burdened with 9L brain tumors have been studied. The heads of normal rats were x-irradiated with single exposures ranging from 1000 R to 2700 R. Following acute exposures greater than 2100 R, all animals died in 8 to 12 days. Approximately 30% of the animals survived beyond 12 days over the range of 1850 to 1950 R; following exposures less than 1850 R, all animals survived the acute radiation effects, and median survival times increased with decreasing exposure. Three fractionated radiation schedules were also studied: 2100 R or 3000 R in 10 equal fractions, and 3000 R in 6 equal fractions, each schedule being administered over a 2 week period. The first schedule produced a MST of greater than 1 1/2 years; the other schedules produced MSTs that were lower. It was determined that by applying a factor of 1.9, similar survival responses of normal rats were obtained with single as with fractionated radiation exposures. Animals burdened with 9L gliosarcoma brain tumors normally died of the disease process within 18 to 28 days ater tumor inoculation. Both single and fractionated radiation therapy resulted in a prolongation of survival of tumor-burdened rats. This prolongation was found to be linearly dependent upon the dose; but only minimally dependent upon the time after inoculation at which therapy was initiated, or upon the fractionation schedule that was used. As with normal animals, similar responses were obtained with single as with fractionated exposures when a factor (1.9) was applied. All tumor-bearing animals died prior to the time that death was observed in normal, irradiated rats. Thus, the 9L gliosarcoma rat brain tumor model can be used for the pre-clinical experimental investigation of new therapeutic schedules involving radiation therapy and adjuvant therapies

Regional brain glucose use in unstressed rats after two days of starvation

International Nuclear Information System (INIS)

Mans, A.M.; Davis, D.W.; Hawkins, R.A.

1987-01-01

Regional brain glucose use was measured in conscious, unrestrained, fed rats and after 2 days of starvation, using quantitative autoradiography and [6- 14 C]glucose. Plasma glucose, lactate, and ketone body concentrations and brain glucose and lactate content were measured in separate groups of rats. Glucose concentrations were lower in starved rats in both plasma and brain; plasma ketone body concentrations were elevated. Glucose use was found to be lower throughout the brain by about 12%. While some areas seemed to be affected more than others, statistical analysis showed that none were exceptionally different. The results could not be explained by increased loss of 14 C as lactate or pyruvate during the experimental period, because the arteriovenous differences of these species were insignificant. The calculated contribution by ketone bodies to the total energy consumption was between 3 and 9% for the brain as a whole in the starved rats and could, therefore, partially account for the depression seen in glucose use. It was concluded that glucose oxidation is slightly depressed throughout the brain after 2 days of starvation

Astrogliosis in the neonatal and adult murine brain post-trauma

DEFF Research Database (Denmark)

Rostworowski, M; Balasingam, V; Chabot, S

1997-01-01

inflammatory cytokines in injury systems in which the presence or absence of astrogliosis could be produced selectively. A stab injury to the adult mouse brain using a piece of nitrocellulose (NC) membrane elicited a prompt and marked increase in levels of transcripts for interleukin (IL)-1alpha, IL-1beta......, and because its exogenous administration to rodents enhanced astrogliosis after adult or neonatal insults. A lack of requirement for endogenous IFN-gamma was demonstrated by three lines of evidence. First, no increase in IFN-gamma transcripts could be found at injury. Second, the administration...

Neuroprotective effects of Ellagic acid on Neonatal Hypoxic Brain ...

African Journals Online (AJOL)

Purpose: To investigate if ellagic acid exerts neuroprotective effects in hypoxic ischemic (HI) brain injury by inhibiting apoptosis and inflammatory responses. Methods: Separate groups of rat pups from post-natal day 4 (D4) were administered with ellagic acid (10, 20 or 40 mg/kg body weight) orally till post- natal day 10 ...

Induction by mercury compounds of brain metallothionein in rats: Hg{sup 0} exposure induces long-lived brain metallothionein

Energy Technology Data Exchange (ETDEWEB)

Yasutake, Akira; Nakano, Atsuhiro [Biochemistry Section, National Institute for Minamata Disease, Kumamoto (Japan); Hirayama, Kimiko [Kumamoto University, College of Medical Science (Japan)

1998-03-01

Metallothionein (MT) is one of the stress proteins which can easily be induced by various kind of heavy metals. However, MT in the brain is difficult to induce because of blood-brain barrier impermeability to most heavy metals. In this paper, we have attempted to induce brain MT in rats by exposure to methylmercury (MeHg) or metallic mercury vapor, both of which are known to penetrate the blood-brain barrier and cause neurological damage. Rats treated with MeHg (40 {mu}mol/kg per day x 5 days, p.o.) showed brain Hg levels as high as 18 {mu}g/g with slight neurological signs 10 days after final administration, but brain MT levels remained unchanged. However, rats exposed to Hg vapor for 7 days showed 7-8 {mu}g Hg/g brain tissue 24 h after cessation of exposure. At that time brain MT levels were about twice the control levels. Although brain Hg levels fell gradually with a half-life of 26 days, MT levels induced by Hg exposure remained unchanged for >2 weeks. Gel fractionation revealed that most Hg was in the brain cytosol fraction and thus bound to MT. Hybridization analysis showed that, despite a significant increase in MT-I and -II mRNA in brain, MT-III mRNA was less affected. Although significant Hg accumulation and MT induction were observed also in kidney and liver of Hg vapor-exposed rats, these decreased more quickly than in brain. The long-lived MT in brain might at least partly be accounted for by longer half-life of Hg accumulated there. The present results showed that exposure to Hg vapor might be a suitable procedure to provide an in vivo model with enhanced brain MT. (orig.) With 4 figs., 1 tab., 27 refs.

[Human umbilical cord blood mononuclear cell transplantation promotes long-term neurobehavioral functional development of newborn SD rats with hypoxic ischemic brain injury].

Science.gov (United States)

Huang, Hui-zhi; Wen, Xiao-hong; Liu, Hui; Huang, Jin-hua; Liu, Shang-quan; Ren, Wei-hua; Fang, Wen-xiang; Qian, Yin-feng; Hou, Wei-zhu; Yan, Ming-jie; Yao, You-heng; Li, Wei-Zu; Li, Qian-Jin

2013-06-01

To explore the effect of human umbilical cord blood mononuclear cells (UCBMC) promoting nerve behavior function and brain tissue recovery of neonatal SD rat with hypoxic ischemic brain injury (HIBI). A modified newborn rat model that had a combined hypoxic and ischemic brain injury as described by Rice-Vannucci was used, early nervous reflex, the Morris water maze and walking track analysis were used to evaluate nervous behavioral function, and brain MRI, HE staining to evaluate brain damage recovery. Newborn rat Rice-Vannucci model showed significant brain atrophy, obvious hemiplegia of contralateral limbs,e.g right step length [(7.67 ± 0.46) cm vs. (8.22 ± 0.50) cm, F = 1.494] and toe distance [(0.93 ± 0.06) cm vs. (1.12 ± 0.55) cm, F = 0.186] were significantly reduced compared with left side, learning and memory ability was significantly impaired compared with normal control group (P vs.(14.22 ± 5.07) s, t = 4.618] and negative geotaxis reflex time [(7.26 ± 2.00) s vs. (11.76 ± 3.73) s, t = 4.755] on postnatal 14 days of HIBI+ transplantation group were significantly reduced compared with HIBI+NaCl group (P vs. (34.04 ± 12.95) s, t = 3.356] and swimming distance [ (9.12 ± 1.21) cm vs.(12.70 ± 1.53) cm, t = 17.095] of HIBI+transplantation group were significantly reduced compared with those of HIBI+NaCl group (P brain volume on postnatal 10 d [ (75.37 ± 4.53)% vs. (67.17 ± 4.08)%, t = -6.017] and 67 d [ (69.05 ± 3.58)% vs.(60.83 ± 3.69)%, t = -7.148]of HIBI+ transplantation group were significantly larger than those of HIBI+NaCl group (P left cortical edema significantly reduced and nerve cell necrosis of HIBI+ transplantation group is not obvious compared with HIBI+NaCl group. Human UCBMC intraperitoneal transplantation significantly promoted recovery of injured brain cells and neurobehavioral function development.

Effect of neonatal dentate gyrus lesion on allothetic and idiothetic navigation in rats

Czech Academy of Sciences Publication Activity Database

Czéh, B.; Stuchlík, Aleš; Wesierska, Malgorzata; Cimadevilla, Jose Maria; Pokorný, J.; Seress, L.; Bureš, Jan

2001-01-01

Roč. 75, č. 2 (2001), s. 190-213 ISSN 1074-7427 R&D Projects: GA ČR GA309/97/0555; GA ČR GA309/00/1656 Institutional research plan: CEZ:AV0Z5011922 Keywords : spatial memory * neonatal brain damage * hippocampus Subject RIV: FH - Neurology Impact factor: 1.830, year: 2001

The observation of blood-brain barrier of organic mercury poisoned rat

International Nuclear Information System (INIS)

Kuwabara, Takeo; Yuasa, Tatsuhiko; Hidaka, Kazuyuki; Igarashi, Hironaka; Kaneko, Kiyotoshi; Miyatake, Tadashi

1989-01-01

Permeability of the blood-brain barrier (BBB) of methymercury chrolide (MMC) intoxicated rat brain was studied in vivo by gadlinium diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI), measuring the longitudinal relaxation time (T 1 ) and the transverse relaxation time (T 2 ). MMC intoxicated rat brain showed the prolonged T 1 in the cerebral white matter and prolonged T 2 in the cerebellar cortex. After Gd-DTPA administration, T 1 of cerebral and cerebellar white matter shortened from 1.647 to 1.344 sec., and 1.290 to 1.223 sec. respectively. On the contrary, T 2 showed no change after Gd-DTPA injection. It was concluded that, although the shortening of T 1 after Gd-DTPA enhancement was rather little when compared with experimental brain ischemia, the shortening of the relaxation time of the MMC intoxicated rat brain was caused by the increased permeability of BBB. (author)

Recurrent hypoinsulinemic hyperglycemia in neonatal rats increases PARP-1 and NF-κB expression and leads to microglial activation in the cerebral cortex.

Science.gov (United States)

Gisslen, Tate; Ennis, Kathleen; Bhandari, Vineet; Rao, Raghavendra

2015-11-01

Hyperglycemia is a common metabolic problem in extremely low-birth-weight preterm infants. Neonatal hyperglycemia is associated with increased mortality and brain injury. Glucose-mediated oxidative injury may be responsible. Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme involved in DNA repair and cell survival. However, PARP-1 overactivation leads to cell death. NF-κB is coactivated with PARP-1 and regulates microglial activation. The effects of recurrent hyperglycemia on PARP-1/NF-κB expression and microglial activation are not well understood. Rat pups were subjected to recurrent hypoinsulinemic hyperglycemia of 2 h duration twice daily from postnatal (P) day 3-P12 and killed on P13. mRNA and protein expression of PARP-1/NF-κB and their downstream effectors were determined in the cerebral cortex. Microgliosis was determined using CD11 immunohistochemistry. Recurrent hyperglycemia increased PARP-1 expression confined to the nucleus and without causing PARP-1 overactivation and cell death. NF-κB mRNA expression was increased, while IκB mRNA expression was decreased. inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) mRNA expressions were decreased. Hyperglycemia significantly increased the number of microglia. Recurrent hyperglycemia in neonatal rats is associated with upregulation of PARP-1 and NF-κB expression and subsequent microgliosis but not neuronal cell death in the cerebral cortex.

Repetitive Neonatal Erythropoietin and Melatonin Combinatorial Treatment Provides Sustained Repair of Functional Deficits in a Rat Model of Cerebral Palsy

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Lauren L. Jantzie

2018-04-01

Full Text Available Cerebral palsy (CP is the leading cause of motor impairment for children worldwide and results from perinatal brain injury (PBI. To test novel therapeutics to mitigate deficits from PBI, we developed a rat model of extreme preterm birth (<28 weeks of gestation that mimics dual intrauterine injury from placental underperfusion and chorioamnionitis. We hypothesized that a sustained postnatal treatment regimen that combines the endogenous neuroreparative agents erythropoietin (EPO and melatonin (MLT would mitigate molecular, sensorimotor, and cognitive abnormalities in adults rats following prenatal injury. On embryonic day 18 (E18, a laparotomy was performed in pregnant Sprague–Dawley rats. Uterine artery occlusion was performed for 60 min to induce placental insufficiency via transient systemic hypoxia-ischemia, followed by intra-amniotic injections of lipopolysaccharide, and laparotomy closure. On postnatal day 1 (P1, approximately equivalent to 30 weeks of gestation, injured rats were randomized to an extended EPO + MLT treatment regimen, or vehicle (sterile saline from P1 to P10. Behavioral assays were performed along an extended developmental time course (n = 6–29. Open field testing shows injured rats exhibit hypermobility and disinhibition and that combined neonatal EPO + MLT treatment repairs disinhibition in injured rats, while EPO alone does not. Furthermore, EPO + MLT normalizes hindlimb deficits, including reduced paw area and paw pressure at peak stance, and elevated percent shared stance after prenatal injury. Injured rats had fewer social interactions than shams, and EPO + MLT normalized social drive. Touchscreen operant chamber testing of visual discrimination and reversal shows that EPO + MLT at least partially normalizes theses complex cognitive tasks. Together, these data indicate EPO + MLT can potentially repair multiple sensorimotor, cognitive, and behavioral realms following PBI, using

Characterization of cortical neuronal and glial alterations during culture of organotypic whole brain slices from neonatal and mature mice.

Science.gov (United States)

Staal, Jerome A; Alexander, Samuel R; Liu, Yao; Dickson, Tracey D; Vickers, James C

2011-01-01

Organotypic brain slice culturing techniques are extensively used in a wide range of experimental procedures and are particularly useful in providing mechanistic insights into neurological disorders or injury. The cellular and morphological alterations associated with hippocampal brain slice cultures has been well established, however, the neuronal response of mouse cortical neurons to culture is not well documented. In the current study, we compared the cell viability, as well as phenotypic and protein expression changes in cortical neurons, in whole brain slice cultures from mouse neonates (P4-6), adolescent animals (P25-28) and mature adults (P50+). Cultures were prepared using the membrane interface method. Propidium iodide labeling of nuclei (due to compromised cell membrane) and AlamarBlue™ (cell respiration) analysis demonstrated that neonatal tissue was significantly less vulnerable to long-term culture in comparison to the more mature brain tissues. Cultures from P6 animals showed a significant increase in the expression of synaptic markers and a decrease in growth-associated proteins over the entire culture period. However, morphological analysis of organotypic brain slices cultured from neonatal tissue demonstrated that there were substantial changes to neuronal and glial organization within the neocortex, with a distinct loss of cytoarchitectural stratification and increased GFAP expression (pglial limitans and, after 14 DIV, displayed substantial cellular protrusions from slice edges, including cells that expressed both glial and neuronal markers. In summary, we present a substantial evaluation of the viability and morphological changes that occur in the neocortex of whole brain tissue cultures, from different ages, over an extended period of culture.

Accurate Learning with Few Atlases (ALFA): an algorithm for MRI neonatal brain extraction and comparison with 11 publicly available methods.

Science.gov (United States)

Serag, Ahmed; Blesa, Manuel; Moore, Emma J; Pataky, Rozalia; Sparrow, Sarah A; Wilkinson, A G; Macnaught, Gillian; Semple, Scott I; Boardman, James P

2016-03-24

Accurate whole-brain segmentation, or brain extraction, of magnetic resonance imaging (MRI) is a critical first step in most neuroimage analysis pipelines. The majority of brain extraction algorithms have been developed and evaluated for adult data and their validity for neonatal brain extraction, which presents age-specific challenges for this task, has not been established. We developed a novel method for brain extraction of multi-modal neonatal brain MR images, named ALFA (Accurate Learning with Few Atlases). The method uses a new sparsity-based atlas selection strategy that requires a very limited number of atlases 'uniformly' distributed in the low-dimensional data space, combined with a machine learning based label fusion technique. The performance of the method for brain extraction from multi-modal data of 50 newborns is evaluated and compared with results obtained using eleven publicly available brain extraction methods. ALFA outperformed the eleven compared methods providing robust and accurate brain extraction results across different modalities. As ALFA can learn from partially labelled datasets, it can be used to segment large-scale datasets efficiently. ALFA could also be applied to other imaging modalities and other stages across the life course.

Serotonin 2A receptor mRNA levels in the neonatal dopamine-depleted rat striatum remain upregulated following suppression of serotonin hyperinnervation.

Science.gov (United States)

Basura, G J; Walker, P D

1999-08-05

Sixty days after bilateral dopamine (DA) depletion (>98%) with 6-hydroxydopamine (6-OHDA) in neonatal rats, serotonin (5-HT) content doubled and 5-HT(2A) receptor mRNA expression rose 54% within the rostral striatum. To determine if striatal 5-HT(2A) receptor mRNA upregulation is dependent on increased 5-HT levels following DA depletion, neonatal rats received dual injections of 6-OHDA and 5,7-dihydroxytryptamine (5,7-DHT) which suppressed 5-HT content by approximately 90%. In these 6-OHDA/5,7-DHT-treated rats, striatal 5-HT(2A) receptor mRNA expression was still elevated (87% above vehicle controls). Comparative analysis of 5-HT(2C) receptor mRNA expression yielded no significant changes in any experimental group. These results demonstrate that upregulated 5-HT(2A) receptor biosynthesis in the DA-depleted rat is not dependent on subsequent 5-HT hyperinnervation. Copyright 1999 Elsevier Science B.V.

Brain and Serum Androsterone is Elevated in Response to Stress in Rats with Mild Traumatic Brain Injury

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Richard J Servatius

2016-08-01

Full Text Available Exposure to lateral fluid percussion (LFP injury consistent with mild traumatic brain injury (mTBI persistently attenuates acoustic startle responses (ASRs in rats. Here, we examined whether the experience of head trauma affects stress reactivity. Male Sprague-Dawley rats were matched for ASRs and randomly assigned to receive mTBI through LFP or experience a sham surgery (SHAM. ASRs were measured post injury days (PIDs 1, 3, 7, 14, 21 and 28. To assess neurosteroids, rats received a single 2.0 mA, 0.5 s foot shock on PID 34 (S34, PID 35 (S35, on both days (2S, or the experimental context (CON. Levels of the neurosteroids pregnenolone (PREG, allopregnanolone (ALLO, and androsterone (ANDRO were determined for the prefrontal cortex, hippocampus and cerebellum. For 2S rats, repeated blood samples were obtained at 15, 30 and 60 min post-stressor for determination of corticosterone (CORT levels after stress or context on PID 34. Similar to earlier work, ASRs were severely attenuated in mTBI rats without remission for 28 days after injury. No differences were observed between mTBI and SHAM rats in basal CORT, peak CORT levels or its recovery. In serum and brain, ANDRO levels were the most stress-sensitive. Stress-induced ANDRO elevations were greater than those in mTBI rats. As a positive allosteric modulator of gamma-aminobutyric acid (GABAA receptors, increased brain ANDRO levels are expected to be anxiolytic. The impact of brain ANDRO elevations in the aftermath of mTBI on coping warrants further elaboration.

Cognitive dysfunction and histological findings in adult rats one year after whole brain irradiation

International Nuclear Information System (INIS)

Akiyama, Katsuhiko; Tanaka, Ryuichi; Sato, Mitsuya; Takeda, Norio

2001-01-01

Cognitive dysfunction and histological changes in the brain were investigated following irradiation in 20 Fischer 344 rats aged 6 months treated with whole brain irradiation (WBR) (25 Gy/single dose), and compared with the same number of sham-irradiated rats as controls. Performance of the Morris water maze task and the passive avoidance task were examined one year after WBR. Finally, histological and immunohistochemical examinations using antibodies to myelin basic protein (MBP), glial fibrillary acidic protein (GFAP), and neurofilament (NF) were performed of the rat brains. The irradiated rats continued to gain weight 7 months after WBR whereas the control rats stopped gaining weight. Cognitive functions in both the water maze task and the passive avoidance task were lower in the irradiated rats than in the control rats. Brain damage consisting of demyelination only or with necrosis was found mainly in the body of the corpus callosum and the parietal white matter near the corpus callosum in the irradiated rats. Immunohistochemical examination of the brains without necrosis found MBP-positive fibers were markedly decreased in the affected areas by irradiation; NF-positive fibers were moderately decreased and irregularly dispersed in various shapes in the affected areas; and GFAP-positive fibers were increased, with gliosis in those areas. These findings are similar to those in clinically accelerated brain aging in conditions such as Alzheimer's disease, Binswanger's disease, and multiple sclerosis. (author)

Concentration change of DA, DOPAC, Glu and GABA in brain tissues in schizophrenia developmental model rats induced by MK-801.

Science.gov (United States)

Liu, Yong; Tang, Yamei; Pu, Weidan; Zhang, Xianghui; Zhao, Jingping

2011-08-01

To explore the related neurobiochemical mechanism by comparing the concentration change of dopamine (DA), dihydroxy-phenyl acetic acid (DOPAC), glutamate (Glu), and γ-aminobutyric acid (GABA) in the brain tissues in schizophrenia (SZ) developmental model rats and chronic medication model rats. A total of 60 neonatal male Spragur-Dawley (SD) rats were randomly assigned to 3 groups at the postnatal day 6: an SZ developmental rat model group (subcutaneous injection with MK-801 at the postnatal day 7-10, 0.1 mg/kg, Bid), a chronic medication model group (intraperitoneal injection at the postnatal day 47-60, 0.2 mg/kg,Qd), and a normal control group (injection with 0.9% normal saline during the corresponding periods). DA, DOPAC, Glu, and GABA of the tissue homogenate from the medial prefrontal cortex (mPFC) and hippocampus were examined with Coularray electrochemic detection by high performance liquid chromatogram technique. The utilization rate of DA and Glu was calculated. Compared with the normal control group, the concentration of DA and DOPAC in the mPFC and the hippocampus in the SZ developmental model group significantly decreased (PGABA concentration and Glu utilization rate in the mPFC also decreased (PGABA system decrease in the mPFC and the DA system function reduces in the hippocampus of SZ developmental rats.

Glucose metabolism of fetal rat brain in utero, measured with labeled deoxyglucose

Energy Technology Data Exchange (ETDEWEB)

Dyve, S [Department of General Physiology and Biophysics, Panum Institute, Copenhagen (Denmark); Gjedde, A [Positron Imaging Laboratories, McConnell Brain Imaging Center, Montreal, Quebec (Canada)

1991-01-01

Mammals have low cerebral metabolic rates immediately after birth and, by inference, also before birth. In this study, we extended the deoxyglucose method to the fetal rat brain in utero. Rate constants for deoxyglucose transfer across the maternal placental and fetal blood-brain barriers, and lumped constant, have not been reported. Therefore, we applied a new method of determining the lumped constant regionally to the fetal rat brain in utero. The lumped constant averaged 0.55 +- 0.15 relative to the maternal circulation. On this basis, we determined the glucose metabolic rate of the fetal rat brain to be one third of the corresponding maternal value, or 19 +- 2 {mu}mol hg{sup -1} min{sup -1}. (author).

Global Proteomic Analysis of Brain Tissues in Transient Ischemia Brain Damage in Rats

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Jiann-Hwa Chen

2015-05-01

Full Text Available Ischemia-reperfusion injury resulting from arterial occlusion or hypotension in patients leads to tissue hypoxia with glucose deprivation, which causes endoplasmic reticulum (ER stress and neuronal death. A proteomic approach was used to identify the differentially expressed proteins in the brain of rats following a global ischemic stroke. The mechanisms involved the action in apoptotic and ER stress pathways. Rats were treated with ischemia-reperfusion brain injuries by the bilateral occlusion of the common carotid artery. The cortical neuron proteins from the stroke animal model (SAM and the control rats were separated using two-dimensional gel electrophoresis (2-DE to purify and identify the protein profiles. Our results demonstrated that the SAM rats experienced brain cell death in the ischemic core. Fifteen proteins were expressed differentially between the SAM rats and control rats, which were assayed and validated in vivo and in vitro. Interestingly, the set of differentially expressed, down-regulated proteins included catechol O-methyltransferase (COMT and cathepsin D (CATD, which are implicated in oxidative stress, inflammatory response and apoptosis. After an ischemic stroke, one protein spot, namely the calretinin (CALB2 protein, showed increased expression. It mediated the effects of SAM administration on the apoptotic and ER stress pathways. Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways. Proteomic analysis suggested that the differential expression of CALB2 during a global ischemic stroke could be involved in the mechanisms of ER stress-induced neuronal cell apoptosis, which occurred via IRE1-alpha/TRAF2 complex formation, with activation of JNK1/2 and p38 MAPK. Based on these results, we also provide the molecular evidence supporting the ischemia

Prevention of reflex natriuresis after acute unilateral nephrectomy by neonatal administration of MSG

International Nuclear Information System (INIS)

Lin, S.Y.; Wiedemann, E.; Deschepper, C.F.; Alper, R.H.; Humphreys, M.H.

1987-01-01

Acute unilateral nephrectomy (AUN) results in natriuresis from the remaining kidney through reflex pathways involving the central nervous system and requiring an intact pituitary gland. The natriuresis is accompanied by an increase in the plasma concentration of a peptide or peptides derived from the N-terminal fragment (NTF) of proopiomelanocortin. The authors measured plasma immunoreactive NTF-like material (IR-NTF) by radioimmunoassay, before and after AUN in control rats and rats treated neonatally with monosodium glutamate (MSG), a procedure that produces neuroendocrine dysfunction by destroying cell bodies in the hypothalamic arcuate nucleus, median eminence, and other brain regions. In control rats, IR-NTF increased from 85.8 +/- 54.9 (SD) to 207 +/- 98.1 fmol/ml after AUN as sodium excretion (U/sub Na/V) doubled. In MSG-treated rats, AUN produced no change in plasma IR-NTF concentration, nor did U/sub Na/V increase. Tissue content of IR-NTF was reduced in the arcuate nucleus and anterior lobe of pituitaries from MSG-treated rats compared with controls, but was no different in the neurointermediate lobe. These results indicate that the hypothalamic lesion produced by neonatal administration of MSG prevents both the increase in plasma IR-NTF concentration and the natruiuresis after AUN, and therefore lend further support to the concept of a casual relationship between these two consequences of AUN

Radio frequency radiation effects on protein kinase C activity in rats' brain

International Nuclear Information System (INIS)

Paulraj, R.; Behari, J.

2004-01-01

The present work describes the effect of amplitude modulated radio frequency (rf) radiation (112 MHz amplitude-modulated at 16 Hz) on calcium-dependent protein kinase C (PKC) activity on developing rat brain. Thirty-five days old Wistar rats were used for this study. The rats were exposed 2 h per day for 35 days at a power density of 1.0 mW/cm 2 (SAR=1.48 W/kg). After exposure, rats were sacrificed and PKC was determined in whole brain, hippocampus and whole brain minus hippocampus separately. A significant decrease in the enzyme level was observed in the exposed group as compared to the sham exposed group. These results indicate that this type of radiation could affect membrane bound enzymes associated with cell signaling, proliferation and differentiation. This may also suggest an affect on the behavior of chronically exposed rats

Marrow stromal cells administrated intracisternally to rats after traumatic brain injury migrate into the brain and improve neurological function

Institute of Scientific and Technical Information of China (English)

胡德志; 周良辅; 朱剑虹

2004-01-01

@@ Marrow stromal cells(MSCs) have been reported to transplant into injured brain via intravenous or intraarterial or direct intracerebral administration.1-3 In the present study, we observed that MSCs migrated into the brain, survived and diffeneriated into neural cells after they were injected into the cisterna magna of rats, and that the behavior of the rats after traumatic brain injury (TBI) was improved.

Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

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Bethany L Peterson

Full Text Available Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6 and older (postnatal day 20 age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

Science.gov (United States)

Peterson, Bethany L; Larson, John; Buffenstein, Rochelle; Park, Thomas J; Fall, Christopher P

2012-01-01

Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6) and older (postnatal day 20) age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

Effects of neonatal excitotoxic lesions in ventral thalamus on social interaction in the rat.

Science.gov (United States)

Wolf, Rainer; Dobrowolny, Henrik; Nullmeier, Sven; Bogerts, Bernhard; Schwegler, Herbert

2017-03-30

The role of the thalamus in schizophrenia has increasingly been studied in recent years. Deficits in the ventral thalamus have been described in only few postmortem and neuroimaging studies. We utilised our previously introduced neurodevelopmental animal model, the neonatal excitotoxic lesion of the ventral thalamus of Sprague-Dawley rats (Wolf et al., Pharmacopsychiatry 43:99-109, 22). At postnatal day (PD7), male pubs received bilateral thalamic infusions with ibotenic acid (IBA) or artificial cerebrospinal fluid (control). In adulthood, social interaction of two animals not familiar to each other was studied by a computerised video tracking system. This study displays clear lesion effects on social interaction of adult male rats. The significant reduction of total contact time and the significant increase in distance between the animals in the IBA group compared to controls can be interpreted as social withdrawal modelling a negative symptom of schizophrenia. The significant increase of total distance travelled in the IBA group can be hypothesised as agitation modelling a positive symptom of schizophrenia. Using a triple concept of social interaction, the percentage of no social interaction (Non-SI%) was significantly larger, and inversely, the percentage of passive social interaction (SI-passive%) was significantly smaller in the IBA group when compared to controls. In conclusion, on the background of findings in schizophrenic patients, the effects of neonatal ventral thalamic IBA lesions in adult male rats support the hypothesis of face and construct validity as animal model of schizophrenia.

Efficacy of Human Adipose Tissue-Derived Stem Cells on Neonatal Bilirubin Encephalopathy in Rats.

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Amini, Naser; Vousooghi, Nasim; Hadjighassem, Mahmoudreza; Bakhtiyari, Mehrdad; Mousavi, Neda; Safakheil, Hosein; Jafari, Leila; Sarveazad, Arash; Yari, Abazar; Ramezani, Sara; Faghihi, Faezeh; Joghataei, Mohammad Taghi

2016-05-01

Kernicterus is a neurological syndrome associated with indirect bilirubin accumulation and damages to the basal ganglia, cerebellum and brain stem nuclei particularly the cochlear nucleus. To mimic haemolysis in a rat model such that it was similar to what is observed in a preterm human, we injected phenylhydrazine in 7-day-old rats to induce haemolysis and then infused sulfisoxazole into the same rats at day 9 to block bilirubin binding sites in the albumin. We have investigated the effectiveness of human adiposity-derived stem cells as a therapeutic paradigm for perinatal neuronal repair in a kernicterus animal model. The level of total bilirubin, indirect bilirubin, brain bilirubin and brain iron was significantly increased in the modelling group. There was a significant decreased in all severity levels of the auditory brainstem response test in the two modelling group. Akinesia, bradykinesia and slip were significantly declined in the experience group. Apoptosis in basal ganglia and cerebellum were significantly decreased in the stem cell-treated group in comparison to the vehicle group. All severity levels of the auditory brainstem response tests were significantly decreased in 2-month-old rats. Transplantation results in the substantial alleviation of walking impairment, apoptosis and auditory dysfunction. This study provides important information for the development of therapeutic strategies using human adiposity-derived stem cells in prenatal brain damage to reduce potential sensori motor deficit.

Neonatal Overnutrition Increases Testicular Size and Expression of Luteinizing Hormone β-Subunit in Peripubertal Male Rats

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Pilar Argente-Arizón

2018-04-01

Full Text Available Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition or 12 pups (controls per dam. Leptin was administered sc (3 µg/g body weight at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but

Neonatal Overnutrition Increases Testicular Size and Expression of Luteinizing Hormone β-Subunit in Peripubertal Male Rats

Science.gov (United States)

Argente-Arizón, Pilar; Castro-González, David; Díaz, Francisca; Fernández-Gómez, María J.; Sánchez-Garrido, Miguel A.; Tena-Sempere, Manuel; Argente, Jesús; Chowen, Julie A.

2018-01-01

Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition) or 12 pups (controls) per dam. Leptin was administered sc (3 µg/g body weight) at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH) beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but with no change

Brain manganese, catecholamine turnover, and the development of startle in rats prenatally exposed to manganese

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