Regulatory T Cells Contribute to Sexual Dimorphism in Neonatal Hypoxic-Ischemic Brain Injury.

BACKGROUND AND PURPOSE: Neonatal encephalopathy caused by hypoxia-ischemia (HI) is a major cause of death and disability in newborns. Clinical and experimental studies suggest a sexual dimorphism in HI-induced brain injury and therapy responses. A major hallmark of HI pathophysiology is the infiltration of peripheral immune cells into the injured brain. However, the specific role of regulatory T cells (Tregs) in neonatal HI is still unknown. METHODS: Nine-day-old mice were exposed to HI by ligation of the right common carotid artery followed by 1 hour hypoxia (10% oxygen). Using immunohistochemistry, flow cytometry, and microarray analyses, Tregs were investigated in the brain, spleen, and blood 24 hours post HI. The functional role of Tregs was evaluated by acute Treg depletion in depletion of regulatory T cells transgenic mice. Brain injury, neuroinflammatory responses, and vascular injury were analyzed via immunohistochemistry and Western blot 48 hours and 7 days after HI. Functional outcome was assessed 3 days and 5 weeks after HI. RESULTS: Female mice revealed an increased cerebral Treg infiltration, coinciding with elevated chemokine receptor expression. Treg depletion in females aggravated HI-induced brain tissue injury, short-term motor deficits, and long-term deficits in exploratory activity, paralleled by an increased microglia and endothelial activation and leukocyte infiltration. Treg depletion in male mice reduced HI-induced brain injury, short-term motor, and long-term cognitive deficits, associated with reduced vascular injury. Ex vivo isolated female Tregs displayed an increased immunosuppressive activity on effector T cell proliferation and an increased gene enrichment in pathways related to enhanced Treg activity. CONCLUSIONS: Tregs from neonatal female mice provide endogenous neuroprotection, whereas Tregs from male mice increase secondary neurodegeneration. As potential mechanisms, we identified intrinsic transcriptional differences associated with enhanced anti-inflammatory activity of female Tregs. Our study emphasizes the urgent need for sex-stratified clinical and preclinical analyses.

Pre- and early postnatal enriched environmental experiences prevent neonatal hypoxia-ischemia late neurodegeneration via metabolic and neuroplastic mechanisms.

Prenatal and early postnatal periods are important for brain development and neural function. Neonatal insults such as hypoxia-ischemia (HI) causes prolonged neural and metabolic dysregulation, affecting central nervous system maturation. There is evidence that brain hypometabolism could increase the risk of adult-onset neurodegenerative diseases. However, the impact of non-pharmacologic strategies to attenuate HI-induced brain glucose dysfunction is still underexplored. This study investigated the long-term effects of early environmental enrichment in metabolic, cell, and functional responses after neonatal HI. Thereby, male Wistar rats were divided according to surgical procedure, sham, and HI (performed at postnatal day 3), and the allocation to standard (SC) or enriched condition (EC) during gestation and lactation periods. In-vivo cerebral metabolism was assessed by means of [18 F]-FDG micro-positron emission tomography, and cognitive, biochemical, and histological analyses were performed in adulthood. Our findings reveal that HI causes a reduction in glucose metabolism and glucose transporter levels as well as hyposynchronicity in metabolic brain networks. However, EC during prenatal or early postnatal period attenuated these metabolic disturbances. A positive correlation was observed between [18 F]-FDG values and volume ratios in adulthood, indicating that preserved tissue by EC is metabolically active. EC promotes better cognitive scores, as well as down-regulation of amyloid precursor protein in the parietal cortex and hippocampus of HI animals. Furthermore, growth-associated protein 43 was up-regulated in the cortex of EC animals. Altogether, results presented support that EC during gestation and lactation period can reduce HI-induced impairments that may contribute to functional decline and progressive late neurodegeneration.

Behavioral and brain morphological analysis of non-inflammatory and inflammatory rat models of preterm brain injury.

Investigations using preclinical models of preterm birth have much contributed, together with human neuropathological studies, for advances in our understanding of preterm brain injury. Here, we evaluated whether the neurodevelopmental and behavioral consequences of preterm birth induced by a non-inflammatory model of preterm birth using mifepristone would differ from those after inflammatory prenatal transient hypoxia-ischemia (TSHI) model. Pregnant Wistar rats were either injected with mifepristone, and pups were delivered on embryonic day 21 (ED21 group), or laparotomized on the 18th day of gestation for 60 min of uterine arteries occlusion. Rat pups were tested postnatally for characterization of developmental milestones and, after weaning, they were behaviorally tested for anxiety and for spatial learning and memory. One month later, brains were processed for quantification of doublecortin (DCX)- and neuropeptide Y (NPY)-immunoreactive cells, and cholinergic varicosities in the hippocampus. ED21 rats did not differ from controls with respect to neonatal developmental milestones, anxiety, learning and memory functions, and neurochemical parameters. Conversely, in TSHI rats the development of neonatal reflexes was delayed, the levels of anxiety were reduced, and spatial learning and memory was impaired; in the hippocampus, the total number of DCX and NPY cells was increased, and the density of cholinergic varicosities was reduced. With these results we suggest that a preterm birth, in a non-inflammatory prenatal environment, does not significantly change neonatal development and adult neurologic outcome. On other hand, prenatal hypoxia and ischemia (inflammation) modifies developmental trajectory, learning and memory, neurogenesis, and NPY GABAergic and cholinergic brain systems.

Quercetin alleviates neonatal hypoxic-ischemic brain injury by inhibiting microglia-derived oxidative stress and TLR4-mediated inflammation.

OBJECTIVE AND DESIGN: Microglia stimulated by oxygen glucose deprivation (OGD) were treated with quercetin to investigate the effect on oxidative stress and the inflammatory response and to explore whether toll-like receptor 4 (TLR4) signaling was involved. In addition, the effect of quercetin on the neurological functions of neonatal mice with hypoxic-ischemic brain injury (HIBI) was examined. MATERIALS AND SUBJECTS: Mouse BV2 microglial cells and postnatal day 7 neonatal mice were used. TREATMENT: A predetermined concentration of quercetin was used in cell experiments. Quercetin was injected i.p. (50 mg/kg) at three time points after HI insult: 0, 24, and 48 h. METHODS: Cell viability assay, Western blotting, qRT-RCR, ELISA, HIBI model construction and behavioral tests. RESULTS: This study first showed that quercetin protected BV2 cells from OGD-induced damage and reversed the changes in microglial oxidative stress-related molecules. Second, quercetin inhibited OGD-induced expression of inflammatory factors in BV2 cells and suppressed TLR4/MyD88/NF-κB signaling. Finally, quercetin was disclosed to be effective in mitigating cerebral infarct volume and cognitive and motor function deficits in HIBI mice. CONCLUSION: These results suggest that the neuroprotective effect of quercetin in HIBI mice is partially due to the inhibition of oxidative stress and TLR4-mediated inflammatory responses in activated microglia.

Mechanism and effects of fructose diphosphate on anti-hypoxia fatigue and learning memory ability.

This study aims to investigate the mechanisms through which fructose diphosphate (FDP) causes anti-hypoxia and anti-fatigue effects and improves learning and memory. Mice were divided into three groups: low-dose FDP (FDP-L), high-dose FDP (FDP-H), and a control group. Acute toxic hypoxia induced by carbon monoxide, sodium nitrite, and potassium cyanide and acute cerebral ischemic hypoxia were used to investigate the anti-hypoxia ability of FDP. The tests of rod-rotating, mouse tail suspension, and swimming endurance were used to explore the anti-fatigue effects of FDP. The Morris water maze experiment was used to determine the impact of FDP on learning and memory ability. Poisoning-induced hypoxic tests showed that mouse survival time was significantly prolonged in the FDP-L and FDP-H groups compared with the control group (p < 0.05). In the exhaustive swimming test, FDP significantly shortened struggling time and prolonged the time of mass-loaded swimming; the rod-rotating test showed that endurance time was significantly prolonged by using FDP (p < 0.05). FDP significantly decreased lactate and urea nitrogen levels and increased hepatic and muscle glycogen and glucose transporter-4 and Na+-K+-ATPase (p < 0.05). To conclude, FDP enhances hypoxia tolerance and fatigue resistance and improves learning and memory ability through regulating glucose and energy metabolism.

Systematic review: long-term cognitive and behavioural outcomes of neonatal hypoxic-ischaemic encephalopathy in children without cerebral palsy.

AIM: To evaluate long-term cognitive and behavioural outcomes of children with neonatal hypoxic-ischaemic encephalopathy (HIE) in the absence of cerebral palsy (CP). METHODS: A systematic search was performed on five databases (EMBASE, Medline, PubMed, Web of Science, PsycInfo). Randomised controlled trials, non-randomised controlled trials, or observational studies, published between 1990 and 2017, that reported long-term (age greater than or equal to four years) cognitive and/or behavioural outcomes of neonatal HIE without CP were included. RESULTS: Seven articles met the inclusion criteria (n = 352 total participants, n = 53 treated with therapeutic hypothermia). Studies reporting cognitive outcome demonstrate impairment of general cognitive abilities in 25-63% of participants with HIE without CP. Specific cognitive difficulties were reported in two studies for attention, executive functioning, memory function and language. Results regarding behavioural outcome possibly indicate a higher risk of difficulties. CONCLUSION: A substantial proportion of children with neonatal HIE who survive without CP are at increased risk of general and/or specific cognitive impairments. Behavioural problems may be more common, but evidence is limited. Results highlight the importance of comprehensive long-term follow-up to identity difficulties and enable intervention to optimise educational achievement and behavioural adjustment.

Sex differences in Hippocampal Memory and Learning following Neonatal Brain Injury: Is There a Role for Estrogen Receptor-α?

Neonatal encephalopathy due to hypoxia-ischemia (HI) leads to severe, life-long morbidities in thousands of neonates born in the USA and worldwide each year. Varying capacities of long-term episodic memory, verbal working memory, and learning can present without cerebral palsy and have been associated with the severity of neonatal encephalopathy sustained at birth. Among children who sustain a moderate degree of HI at birth, girls have larger hippocampal volumes compared to boys. Clinical studies indicate that female neonatal brains are more resistant to the effects of neonatal HI, resulting in better long-term cognitive outcomes compared to males with comparable brain injury. Our most recent mechanistic studies have addressed the origins and cellular basis of sex differences in hippocampal neuroprotection following neonatal HI-related brain injury and implicate estrogen receptor-α (ERα) in the neurotrophin receptor-mediated hippocampal neuroprotection in female mice. This review summarizes the recent findings on ERα-dependent, neurotrophin-mediated hippocampal neuroprotection and weighs the evidence that this mechanism plays an important role in preservation of long-term memory and learning following HI in females.

The long-term effect of perinatal asphyxia on hippocampal volumes.

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) in term-born infants can lead to memory problems. The hippocampus is important for long-term episodic memory. The primary aim was to investigate the effect of HIE on hippocampal volumes in 9- to 10-year-old children. The secondary aim was to investigate the association between hippocampal volumes and previously found impaired memory and cognitive functions in the current cohort. METHODS: In total 26 children with mild HIE, 26 with moderate HIE, and 37 controls were included. The intelligence quotient (IQ) and memory were tested. A 3D-volumetric MRI was obtained. Brain segmentation was performed for hippocampal volumes and intracranial volume. The differences in hippocampal volumes, memory, and IQ between the groups were determined. Multivariable linear regression analyses were performed, including hippocampal volume as a percentage of intracranial volume as a dependent variable. RESULTS: Smaller hippocampal volumes were found in moderate HIE (p < 0.001), with a trend toward smaller volumes in mild HIE, compared to controls. In multivariable linear regression analysis, hippocampal volume as a percentage of intracranial volume was significantly associated with long-term visuospatial memory. CONCLUSION: Children with moderate HIE had smaller hippocampal volumes than controls, with a trend toward smaller volumes following mild HIE. Reduced hippocampal volumes were associated with poorer long-term visuospatial memory.

Emotional consciousness preserved in patients with disorders of consciousness?

Increasing evidence from studies of brain responses to subject's own name (SON) indicates that residual consciousness is preserved in patients with disorders of consciousness (DOC) and that specific network activation might provide evidence of consciousness. However, it remains unclear whether SON is suitable for detection of emotional consciousness; moreover, the particular aspects of brain network organization that are critical for consciousness are unknown. The present study used an innovative approach to explore affective consciousness in patients with DOC during emotional stimuli. EEG data were acquired from 15 patients and 15 healthy volunteers. We analyzed brain potentials and functional network connectivity with a passive emotional paradigm based on graph theoretical methods. Larger N1 or P3a was detected in patients upon exposure to emotional sound, relative to neutral stimuli. Brain topology revealed that emotional sound evoked significantly stronger network linkages in healthy controls; additionally, it evoked several connectivity changes in patients with DOC. In conclusion, emotional consciousness might be partially preserved in patients with DOC; moreover, EEG network patterns could provide new insights into the neural activity of emotional perception in these patients.

Change in Function Over Inpatient Rehabilitation After Hypoxic Ischemic Brain Injury: A Population-Wide Cohort Study.

OBJECTIVE: To estimate change in motor, cognitive, and overall functional performance during inpatient rehabilitation (IR) and to identify potential determinants of these outcomes among patients with hypoxic-ischemic brain injury (HIBI). DESIGN: Population-based retrospective cohort study using Ontario's health administrative data. SETTING: Inpatient rehabilitation. PARTICIPANTS: Survivors of HIBI 20 years and older discharged from acute care between fiscal years 2002-2003 and 2010-2011 and admitted to IR within 1 year of acute care discharge (N=159). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Functional status as measured by FIM, total, and scores on motor and cognitive subscales. RESULTS: A higher proportion (77%) of HIBI patients in the study were male and 28% were older than 65 years. We observed material improvements in FIM total, motor, and cognitive scores from across the IR episode. Potential determinants of total FIM gain were living in rural location (ß, 10.4; 95% CI, 0.21-21), having shorter preceding acute care length of stay (15-30 vs >60 days ß, 10.4; 95% CI, 1.4-19.5), and failing to proceed directly to IR following acute care discharge (ß, 8.7; 95% CI, 1.8-15.5). Motor FIM gain had similar identified potential determinants. Identified potential determinants of cognitive FIM gain were shorter (ie, 31-60 vs >60 days) preceding acute care, longer IR and length of stay, and proceeding directly to IR. There were no sex differences in functional gain. CONCLUSIONS: Inpatient rehabilitation is beneficial to HIBI survivors. Timely access to these services may be crucial in achieving optimal outcomes for these patients.

The efficacy of ozone therapy in neonatal rats with hypoxic ischemic brain injury.

OBJECTIVES: This study is aimed to determine the effect of ozone therapy in neonatal rats with experimentally induced hypoxic ischemic brain injury (HIBI). METHODS: The study included 7-d-old male Wistar rats that were randomized to the sham, control, ozone 1, and ozone 2 groups. All rats except those in the sham group were kept in a hypoxia chamber, and then the rats in the control group were given 0.5 mL of saline. Those in the ozone 1 group were given ozone 1 mg kg-1 intraperitoneally, and those in the ozone 2 group were given ozone 2 mg kg-1 intraperitoneally. RESULTS: There were significantly fewer apoptotic neurons in the right hemispheres of the rats in the ozone 1 and ozone 2 groups than in the control group (p < 0.001 and p < 0.001, respectively). There were significantly fewer apoptotic neurons in the right hemispheres of the rats in the ozone 2 group than in the ozone 1 group (p < 0.001). Morris Water Maze (MWM) test results were similar in the ozone 2 and sham groups. CONCLUSIONS: The present study's findings show that ozone therapy reduced neuronal apoptosis and improved cognitive function in neonatal rats with experimentally induced HIBI (Tab. 2, Ref. 30).

Resveratrol Reverses the Synaptic Plasticity Deficits in a Chronic Cerebral Hypoperfusion Rat Model.

BACKGROUND: Dementia is the most prevalent neurological disease in aged people. Chronic cerebral hypoperfusion (CCH) is one of the causes of vascular dementia (VaD) and is also an etiological factor for Alzheimer's disease (AD). However, effective therapy for those two diseases is still missing. Resveratrol is a polyphenol produced by plants that have multiple biological functions, such as increased life span and delay in the onset of diseases associated with aging. It is known supplement with resveratrol could exert neuroprotection against multiple injury factors induced neuronal death and degeneration, as well as the cognitive decline of CCH rat model. METHODS: The morris water maze was used to evaluate the learning and memory, electrophysiological recording was used to detect the synaptic plasticity, the Golgi staining was used to examine the change of dendritic spines, the western blot was used to detect the proteins levels. RESULTS: We reported that resveratrol pretreatment effectively restore the synaptic plasticity in CCH rats both functional and structural. We also found that the PKA-CREB activation may be a major player in resveratrol-mediated neuroprotection in CCH model. CONCLUSIONS: Our data provide the mechanistic evidence for the neuroprotective effects of resveratrol in vascular dementia.

Fibroblast growth factor 2 improves cognitive function in neonatal rats with hypoxic ischaemic brain injury.

OBJECTIVE: To determine the effect of fibroblast growth factor 2 on cognitive function in neonatal rats with hypoxic-ischaemic brain injury. METHODS: The randomised controlled study was conducted from January to June 2011 at Mersin University, School of Medicine, Experimental Animals Research Laboratory and Physiology Behaviour Laboratory, Mersin, Turkey. It included 7-d-old male rats that were randomised into four groups: fibroblast growth factor 2-20, fibroblast growth factor 2-40, control and sham. All the rats, except those in the sham group, were kept in a hypoxia chamber containing 8% oxygen for 2 hours following ligation of the right carotid artery. After hypoxic-ischaemic brain injury was induced, 20 ng g-1 or 40 ng g-1 of fibroblast growth factor 2 was administered via the intraperitoneal route. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling method was used to evaluate neuronal apoptosis. The Morris water maze (MWM) test was administered to the rats at age 14 weeks. RESULTS: Of the 78 rats on the study, 18 (23%) were in the sham group, while the other three groups had 20 (25.6%) rats each. The number of apoptotic neurons in the right hemisphere in the experimental groups was significantly lower than in the control group (p=0.004 and p<0.001). The number of apoptotic neurons in the right hemisphere in the fibroblast growth factor 2-40 group was significantly lower than in the fibroblast growth factor 2-20 group (p<0.001). Moreover, fibroblast growth factor 2improved Morris water maze test cognitive performance in a dose-dependent manner. CONCLUSIONS: Fibroblast growth factor 2 treatment reduced neuronal apoptosis and improved cognitive functioning in neonatal rats with experimentally-induced hypoxic-ischaemic brain injury.

Assessment of long-term safety and efficacy of intranasal mesenchymal stem cell treatment for neonatal brain injury in the mouse.

BACKGROUND: For clinical translation, we assessed whether intranasal mesenchymal stem cell (MSC) treatment after hypoxia-ischemia (HI) induces neoplasia in the brain or periphery at 14 mo. Furthermore, the long-term effects of MSCs on behavior and lesion size were determined. METHOD: HI was induced in 9-d-old mice. Pups received an intranasal administration of 0.5 × 10(6) MSCs or vehicle at 10 d post-HI. Full macroscopical and microscopical pathological analysis of 39 organs per mouse was performed. Sensorimotor behavior was assessed in the cylinder-rearing test at 10 d, 28 d, 6 mo, and 9 mo. Cognition was measured with the novel object recognition test at 3 and 14 mo post-HI. Lesion size was determined by analyzing mouse-anti-microtubule-associated protein 2 (MAP2) and mouse-anti-myelin basic protein (MBP) staining at 5 wk and 14 mo. RESULTS: At 14 mo post-HI, we did not observe any neoplasia in the nasal turbinates, brain, or other organs of HI mice treated with MSCs. Furthermore, our results show that MSC-induced improvement of sensorimotor and cognitive function is long lasting. In contrast, HI-vehicle mice showed severe behavioral impairment. Recovery of MAP2- and MBP-positive area lasted up to 14 mo following MSC treatment. CONCLUSION: Our results provide strong evidence of the long-term safety and positive effects of MSC treatment following neonatal HI in mice.

The long-term health, social, and financial burden of hypoxic-ischaemic encephalopathy.

Infants who suffer hypoxic-ischaemic encephalopathy (HIE) at term are at risk of dying or developing severe cerebral palsy (CP). Children with severe CP often have other neurodevelopmental disabilities, which may affect their quality of life as much as the CP itself. New treatments for HIE, such as cooling, may improve motor outcomes, but affected infants may still have significant cognitive or communication problems. Infants who have experienced HIE and develop CP will require significant medical input throughout childhood and adult life. The costs of this medical input are high, but the indirect costs to the child, his or her family, and the relevant social services and education systems are many times greater. When demonstrating the cost-effectiveness of interventions aimed at preventing or treating HIE, these additional costs should be taken into account.

Prophylactic Subacute Administration of Zinc Increases CCL2, CCR2, FGF2, and IGF-1 Expression and Prevents the Long-Term Memory Loss in a Rat Model of Cerebral Hypoxia-Ischemia.

Prophylactic subacute administration of zinc decreases lipoperoxidation and cell death following a transient cerebral hypoxia-ischemia, thus suggesting neuroprotective and preconditioning effects. Chemokines and growth factors are also involved in the neuroprotective effect in hypoxia-ischemia. We explored whether zinc prevents the cerebral cortex-hippocampus injury through regulation of CCL2, CCR2, FGF2, and IGF-1 expression following a 10 min of common carotid artery occlusion (CCAO). Male rats were grouped as follows: (1) Zn96h, rats injected with ZnCl2 (one dose every 24 h during four days); (2) Zn96h + CCAO, rats treated with ZnCl2 before CCAO; (3) CCAO, rats with CCAO only; (4) Sham group, rats with mock CCAO; and (5) untreated rats. The cerebral cortex-hippocampus was dissected at different times before and after CCAO. CCL2/CCR2, FGF2, and IGF-1 expression was assessed by RT-PCR and ELISA. Learning in Morris Water Maze was achieved by daily training during 5 days. Long-term memory was evaluated on day 7 after learning. Subacute administration of zinc increased expression of CCL2, CCR2, FGF2, and IGF-1 in the early and late phases of postreperfusion and prevented the CCAO-induced memory loss in the rat. These results might be explained by the induction of neural plasticity because of the expression of CCL2 and growth factors.

Sildenafil mediates blood-flow redistribution and neuroprotection after neonatal hypoxia-ischemia.

BACKGROUND AND PURPOSE: The best conceivable treatment for hypoxia-ischemia (HI) is the restoration of blood flow to the hypoxic-ischemic region(s). Our objective was to examine whether boosting NO-cGMP signaling using sildenafil citrate, a phosphodiesterase-type 5 inhibitor, could modify cerebral blood flow and reduce lesions in the developing brain. METHODS: HI was induced in P7 Sprague-Dawley rats by unilateral carotid artery occlusion and hypoxia, and followed by either PBS or sildenafil. Blood-flow velocities were measured by ultrasound imaging with sequential Doppler recordings to evaluate collateral recruitment. Cell death, blood-brain barrier integrity, and glial activation were analyzed by immunohistochemistry. Motor behavior was evaluated using an open-field device adapted to neonatal animals. RESULTS: Sildenafil citrate (10 mg/kg) induced collateral patency, reduced terminal dUTP nick-end labeling-positive cells, reactive astrogliosis, and macrophage/microglial activation at 72 hours and 7 days post-HI. Sildenafil also reduced the number of terminal dUTP nick-end labeling-positive endothelial cells within lesion site. Seven days after HI and sildenafil treatment, tissue loss was significantly reduced, and animals recovered motor coordination. CONCLUSIONS: Our findings strongly indicate that sildenafil citrate treatment, associated with a significant increase in cerebral blood flow, reduces HI damage and improves motor locomotion in neonatal rats. Sildenafil may represent an interesting therapeutic strategy for neonatal neuroprotection.

A combination of mild hypothermia and sevoflurane affords long-term protection in a modified neonatal mouse model of cerebral hypoxia-ischemia.

BACKGROUND: Infant brain injury from hypoxia-ischemia (HI) can lead to life-long impairment, but protective strategies are lacking. Short-term but not long-term protection has been demonstrated in the Rice-Vannucci neonatal brain ischemia model (RVM) by volatile anesthetic administration before HI, while exposure during HI has not been tested. In the current study, we evaluated a combination of sevoflurane and mild hypothermia as a protective approach during HI, both short- and long-term, by introducing intubation and mechanical ventilation to the RVM. METHODS: The right common carotid artery was ligated in 10-day-old mice during brief sevoflurane anesthesia, followed by a 2-hour recovery with the dam. Littermates were then randomized to either: HI spontaneously breathing 10% oxygen for 60 minutes (the classical RVM); HI-Protect mild hypothermia and orotracheal intubation and mechanical ventilation with 3.5% sevoflurane in 10% oxygen for 60 minutes; or Room Air spontaneously breathing room air for 60 minutes. In a nonsurviving cohort, cerebral oxygenation was monitored in the area at risk and the contralateral hemisphere during HI or HI-Protect using visible-light spectroscopy (Spectros Corp). Mean arterial blood pressure and heart rate were measured. Arterial blood gases were obtained. Right/left brain hemispheric weight ratios and brain damage scores were determined 1 week after HI. In another group, learning and behavior were assessed in young adulthood (9 weeks) using spontaneous locomotion, Morris water maze, and apomorphine injection. RESULTS: During HI, ipsilateral and contralateral brain oxygenation, arterial blood pressures, blood gases, and glucose levels were similar in both ischemic groups, while heart rate was slower in the HI-Protect group. One week after ischemia, brain hemispheric weight ratios and injury scores in several brain regions were significantly worse after HI, compared with HI-Protect. Nine weeks after HI, Morris water maze hidden platform and reversal platform escape latencies, measures of spatial memory function, were superior after HI-Protect, compared with HI (P < 0.0001). HI-Protect animals demonstrated significantly less circling behavior after an apomorphine challenge (P < 0.0001), a measure of striatal integrity. CONCLUSIONS: To test the neuroprotective effects of volatile anesthetics during neonatal brain ischemia, we developed a modification of the RVM. By using mechanical ventilation and endotracheal intubation, sevoflurane administration during HI was survivable. The combination of sevoflurane administration and mild hypothermia during HI conferred not only short-term structural, but also long-term functional protection, compared with littermates treated according to the RVM. These findings warrant further studies to improve neurological outcome in critically ill infants.

[Effect of IGF-1 on long-term anxiety-like behavior in rats after hypoxic-ischemic brain damage].

OBJECTIVE: To observe the changes in anxiety-like behavior among rats in the recovery stage after hypoxic-ischemic brain damage (HIBD) during the perinatal period and to investigate the effect of insulin-like growth factor 1 (IGF-1) on the long-term anxiety-like behavior and its action mechanism among rats with HIBD. METHODS: Ninety neonatal rats (7 days old) were randomly and equally divided into normal control, HIBD, and HIBD+IGF-1 groups. A neonatal rat model of HIBD was established by Rice method in the HIBD and HIBD+IGF-1 groups. The rats in the HIBD+IGF-1 group were intraperitoneally injected with IGF-1 (0.2 mg/kg) immediately after HIBD, and the other two groups were intraperitoneally injected with an equal volume of normal saline. The anxiety-like behavior was evaluated by elevated plus-maze test on postnatal days 21 and 28. The expression of tyrosine hydroxylase (TH) in the substantia nigra was measured by immunohistochemistry on postnatal days 14, 21, and 28. RESULTS: On postnatal days 21 and 28, the open-arm time (OAT) and percentage of OAT for the HIBD and HIBD+IGF-1 groups were significantly lower than those for the normal control group (P<0.05), but there were no significant differences between the HIBD and HIBD+IGF-1 groups (P>0.05); the percentage of open arm entry showed no significant difference between the three groups (P>0.05). On postnatal day 14, there were no significant differences in percentage of TH immunostaining-positive area between the three groups (P>0.05). On postnatal days 21 and 28, the HIBD and HIBD+IGF-1 groups had significantly lower percentages of TH immunostaining-positive area than the normal control group (P<0.05), but there was no significant difference between the HIBD and HIBD+IGF-1 groups (P>0.05). CONCLUSIONS: HIBD in the perinatal period may cause the changes in anxiety-like behavior in adolescent rats, which may be related to decreased expression of TH in the substantia nigra. Neonatally given IGF-1 cannot improve the long-term anxiety-like behavior in rats after HIBD, and it does not affect TH expression in the substantia nigra. IGF-1 may not regulate the changes in long-term anxiety-like behavior in adolescent rats.

Seven- to eight-year follow-up of the CoolCap trial of head cooling for neonatal encephalopathy.

INTRODUCTION: We sought to determine whether 18- to 22-mo neurodevelopmental outcomes predicted functional outcomes at 7-8 y for survivors of the CoolCap study of therapeutic hypothermia for neonates with hypoxic-ischemic encephalopathy. RESULTS: WeeFIM ratings were completed at 7-8 y of age on 62 (32 cooled; 30 standard care) of 135 surviving children who had had neurodevelopmental assessment at 18 mo. There was 1 refusal, 58 lost to follow-up, and 14 children whose centers declined to participate. Disability status at 18 mo was strongly associated with WeeFIM ratings (P < 0.001); there was no significant effect of treatment (P = 0.83). DISCUSSION: Functional outcome at 7-8 y of survivors of neonatal encephalopathy is associated with 18-mo neurodevelopmental assessment, supporting the long-term predictive value of a favorable outcome at 18 mo assessed by published trials of therapeutic hypothermia. METHODS: All surviving children who participated in the CoolCap study and were assessed at 18 mo were eligible for reassessment using the WeeFIM instrument that qualitatively measures self-care, mobility, and cognitive function. Center investigators obtained consent from the families for a certified researcher to administer the WeeFIM instrument by phone.