Effects of all three trimester moderate binge alcohol exposure on the foetal hippocampal formation and olfactory bulb.

OBJECTIVE: Pre-natal alcohol exposure results in injury to the hippocampus and olfactory bulb,but currently there is no consensus on the critical window of vulnerability. This study tested thehypothesis that pre-natal exposure to a moderate dose of alcohol during all three trimesterequivalentsalters development of the hippocampal formation and olfactory bulb in an ovinemodel, where all brain development occurs pre-natally as it does in humans.Research design and methods: Pregnant sheep were divided into saline control and abinge drinking groups (alcohol dose 1.75 g kg(-1); mean peak blood alcohol concentration189 + 19mg dl(-1)). OUTCOME AND RESULTS: The density, volume and total cell number were not different betweengroups for the dentate gyrus, pyramidal cells in the CA1 and CA2/3 fields and mitral cells in theolfactory bulb. CONCLUSIONS: A moderate dose of alcohol administered in a binge pattern throughout gestationdoes not alter cell numbers in the hippocampus or olfactory bulb and exposure during thethird trimester-equivalent is required for hippocampal injury, unless very high doses of alcoholare administered. This has important implications in establishing the sensitivity of imagingmodalities such as MRI in which volumetric measures are being studied as biomarkers forpre-natal alcohol exposure.

Suppression and epigenetic regulation of MiR-9 contributes to ethanol teratology: evidence from zebrafish and murine fetal neural stem cell models.

BACKGROUND: Fetal alcohol exposure produces multiorgan defects, making it difficult to identify underlying etiological mechanisms. However, recent evidence for ethanol (EtOH) sensitivity of the miRNA miR-9 suggests one mechanism, whereby EtOH broadly influences development. We hypothesized that loss of miR-9 function recapitulates aspects of EtOH teratology. METHODS: Zebrafish embryos were exposed to EtOH during gastrulation, or injected with anti-miR-9 or nonsense control morpholinos during the 2-cell stage of development and collected between 24 and 72 hours postfertilization (hpf). We also assessed the expression of developmentally important, and known miR-9 targets, FGFR-1, FOXP2, and the nontargeted transcript, MECP2. Methylation at CpG islands of mammalian miR-9 genes was assessed in fetal murine neural stem cells (mNSCs) by methylation-specific PCR, and miRNA processing assessed by qRT-PCR for pre-miR-9 transcripts. RESULTS: EtOH treatment and miR-9 knockdown resulted in similar cranial defects including microcephaly. Additionally, EtOH transiently suppressed miR-9, as well as FGFR-1 and FOXP2, and alterations in miR-9 expression were correlated with severity of EtOH-induced teratology. In mNSCs, EtOH increased CpG dinucleotide methylation at the miR-9-2 locus and accumulation of pre-miR-9-3. CONCLUSIONS: EtOH exerts regulatory control at multiple levels of miR-9 biogenesis. Moreover, early embryonic loss of miR-9 function recapitulated the severe range of teratology associated with developmental EtOH exposure. EtOH also disrupts the relationship between miR-9 and target gene expression, suggesting a nuanced relationship between EtOH and miRNA regulatory networks in the developing embryo. The implications of these data for the expression and function of mature miR-9 warrant further investigation.

The emergence of a texas collaboration to improve well-being in learning health systems.

Prior models of well-being have focused on resolving issues at different levels within a single institution. Changes over time in medicine have resulted in massive turnover and reduced clinical hours that portray a deficit-oriented system. As developments to improve purpose and professional satisfaction emerge, the Texas Medical Association Committee on Physician Health and Wellness (PHW) is committed to providing the vehicle for a statewide collaboration and illuminating the path forward.To describe the existing health and wellness resources in Texas academic medical centers and understand the gaps in resources and strategies for addressing the health and wellness needs in the medical workforce, and in student and trainee populations.Various methods were utilized to gather information regarding health and wellness resources at Texas academic medical centers. A survey was administered to guide a Think Tank discussion during a PHW Exchange, and to assess resources at Texas academic medical centers. Institutional representatives from all Texas learning health systems were eligible to participate in a poster session to share promising practices regarding health and wellness resources, tools, and strategies.Survey responses indicated a need for enhancing wellness program components such as scheduled activities promoting health and wellness, peer support networks, and health and wellness facilities in academic medical centers. Answers collected during the Think Tank discussion identified steps needed to cultivate a culture of wellness and strategies to improve and encourage wellness.The Texas Medical Association Committee on Physician Health and Wellness and PHW Exchange provided a forum to share best practices and identify gaps therein, and has served as a nidus for the formation of a statewide collaboration for which institutional leaders of academic medical centers have affirmed the need to achieve the best result.

Neonatal amphetamine exposure and hippocampus-mediated behaviors.

Previous studies linking amphetamine use during pregnancy to changes in the behavioral development of affected infants have greatly increased society's level of concern regarding amphetamine use by women of reproductive age. The aim of this study was to investigate whether exposure to d-amphetamine sulfate during the brain growth spurt, the most dynamic period of brain development, alters hippocampus-mediated behaviors during both pre-adolescence and young adulthood. Sprague-Dawley rat pups were intragastrically administered a milk formula containing 0, 5, 15 or 25 mg/kg/day of amphetamine from postnatal day (PD) 4-9. Following weaning, the effects of neonatal amphetamine exposure on hippocampus-mediated behaviors were assessed using the open-field, the water maze, and the conditioned taste aversion behavioral tasks. Results from these behavioral tests revealed that while amphetamine exposure during the brain growth spurt alters behaviors in open-field testing, it does not interfere with performance in either the water maze or the conditioned taste aversion paradigm. These results offer speculation that the effects of neonatal amphetamine exposure on hippocampus-mediated behaviors may be related to interactions between the "temporal" (time of drug exposure) and "regional" (different regions of the hippocampus) vulnerability issues.

Neonatal alcohol exposure differentially alters clock gene oscillations within the suprachiasmatic nucleus, cerebellum, and liver of adult rats.

BACKGROUND: In rats, alcohol exposure during the period of rapid brain growth produces long-term changes in the free-running period, photoentrainment and phase-shifting responses of the circadian rhythm in wheel-running behavior. To determine whether these alterations in circadian behavior are associated with permanent damage to the circadian timekeeping mechanism or reconfiguration of its molecular components, we examined the long-term effects of neonatal alcohol exposure on clock gene rhythms in the pacemaker located in the suprachiasmatic nucleus (SCN) and in other brain or peripheral tissues of adult rats. METHODS: Artificially reared male rat pups were exposed to alcohol (4.5 g/kg/d) or isocaloric milk formula (gastrostomy control; GC) on postnatal days 4 to 9. At 3 months of age, animals were exposed to constant darkness and then SCN, cerebellum, and liver tissue were harvested at 6-hour intervals for subsequent analysis of Period1 (Per1), Per2, Cryptochrome1 (Cry1), Bmal1, and Rev-erbalpha mRNA levels by quantitative PCR. RESULTS: In the SCN, cerebellum and liver, Per1, Per2, Cry1, Bmal1, and Rev-erbalpha expression oscillated with a similar amplitude (peak-to-trough differences of 2- to 9-fold) and phase in the suckle control (SC) and GC groups. These clock gene rhythms in control animals were marked by peak expression of Per1, Per2, Cry1, and Rev-erbalpha during the subjective day and of Bmal1 during the subjective night. The EtOH group was distinguished by altered rhythms in the expression of specific clock genes within the SCN, cerebellum and liver. In EtOH-treated rats, the SCN rhythm in Cry1 expression was strongly damped and the Per2 rhythms in the cerebellum and liver were phase-advanced such that peak expression occurred during the mid-subjective day. CONCLUSIONS: These results demonstrate alcohol exposure during the brain growth spurt alters the circadian regulation of some molecular components of the clock mechanism in the rat SCN, cerebellum, and liver. The observed alterations in the temporal configuration of essential "gears" of the molecular clockworks may play a role in the long-term effects of neonatal alcohol exposure on the regulation of circadian behavior.

Estimation of neuronal numbers in rat hippocampus following neonatal amphetamine exposure: a stereology study.

In this study, the effects of amphetamine exposure during a portion of the brain growth spurt on the total number of hippocampal pyramidal cells (CA1/CA3 subregions) and the granule cells (dentate gyrus) were examined in both neonatal and adult rats. Intragastric intubation was used to administer 5, 15 or 25 mg/kg/day of amphetamine to Sprague-Dawley rat pups from PDs 4-9. Unbiased stereology was used to estimate the total number of cells present within each hippocampal subregion at both PD 9 and PD 68. The results indicated that neonatal amphetamine exposure did not alter the cell number, the reference volume or the density in any of the hippocampal subregions assessed, regardless of age. However, amphetamine significantly altered the rate of neuronal incorporation in both the hippocampal CA3 subregion and the dentate gyrus, and this effect appeared to be dose-related with the most robust effect observed in the highest amphetamine dose. While these findings did not demonstrate significant injurious effects of neonatal amphetamine treatment on the number of hippocampal neurons, these data suggest that amphetamine may interfere with proper hippocampal development. Future studies employing more sensitive measurements or exposing amphetamine during an alternate period of development may provide more information regarding amphetamine-mediated developmental neurotoxicity.

Maternal adrenocorticotropin, cortisol, and thyroid hormone responses to all three-trimester equivalent repeated binge alcohol exposure: ovine model.

Alcohol-mediated alterations in hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-thyroid axis function are two proposed mechanisms by which alcohol causes neurodevelopmental injury to the fetus. We previously reported that third-trimester equivalent only alcohol exposure in sheep results in increases in the maternal and fetal adrenocorticotropin and cortisol levels, and decreases in the fetal thyroid hormones T(3) and T(4) and maternal T(3) levels. In this study, we wished to characterize the maternal HPA and hypothalamic-pituitary-thyroid hormone responses to repeated binge alcohol exposure during all three-trimester equivalents of pregnancy in sheep. Pregnant ewes received intravenous infusions of alcohol at doses of 0.75, 1.25, or 1.75 g/kg over 1h with mean peak blood alcohol concentrations of 90, 126, or 183 mg/dl, respectively, on 3 consecutive days each week beginning on gestational day (GD) 4. Maternal blood samples were collected on GDs 6, 40, 90, and 132. Maternal plasma concentrations of adrenocorticotropin and cortisol increased in response to the high alcohol dose, and the magnitude of these elevations was not different across gestation. Thyroid hormone levels were not different when comparing among treatment groups at any time point during gestation. However, there was an ontogenetic decrease in the maternal T(3) concentration beginning between GDs 6 and 40 and a decrease in maternal T(4) and free T(4) beginning between GDs 40 and 90. The current findings suggest that (1) maternal alcohol consumption at any time during gestation stimulates the HPA axis, (2) maternal HPA responsiveness to alcohol does not change across gestation, (3) binge alcohol exposure at these doses lasting all three-trimester equivalent of human brain development does not reduce maternal thyroid hormone concentration, (4) alterations in fetal thyroid function in response to alcohol exposure do not occur as a result of diminished maternal thyroid hormone contribution, and (5) there is an ontogenetic decrease in ovine maternal thyroid hormones over gestation.

Effects of nicotine exposure during prenatal or perinatal period on cell numbers in adult rat hippocampus and cerebellum: a stereology study.

Smoking during pregnancy poses a potential risk to unborn children. The present study examined the long-term effects of early nicotine exposure on the number of pyramidal and granule cells in the hippocampus, and Purkinje cells in the cerebellar vermis. The loss of neurons is the most severe form of brain injury with significant functional implications. In this study, rats were exposed to nicotine during either the prenatal (PRE) period or both the prenatal and early postnatal (PERI) period. It was hypothesized that nicotine treatment would result in long-term decreases in neuronal numbers, and that PERI treatment would be more detrimental to these cell populations than the PRE treatment. The results showed that neither PRE nor PERI nicotine exposure reduces the numbers of pyramidal, granule or Purkinje cells. Neither the regions where these cells reside, nor the cell densities were affected by nicotine. Although no significant cell loss was observed, the current nicotine exposure regimens may lead to alterations in cellular functions or cytoarchitectures. The present results in conjunction with previous reports showing significant cell loss from nicotine exposure during the brain growth spurt suggest that "patch-like" nicotine exposure during prenatal period may alter the sensitivity or the responsiveness of the developing brain to the injurious effects of nicotine during the most vulnerable stage of brain development - the brain growth spurt. Furthermore, the current stereology cell counting results are not in agreement with some reports in the literature, and this discrepancy may simply be a function of different cell counting techniques used.

The interactive effect of alcohol and nicotine on NGF-treated pheochromocytoma cells.

Previous studies have reported that alcohol exposure reduces the number of neuronal-like pheochromocytoma (PC12) cells in culture. In this study, the interactive effect of coexposure of alcohol and nicotine on PC12 cell numbers was examined in comparison with the effect derived from alcohol or nicotine exposure individually. Moreover, the role of apoptosis in mediating changes in PC12 cell numbers was also investigated. It was hypothesized that alcohol would result in cell loss, and the presence of nicotine would attenuate the damaging effects of alcohol. PC12 cells were exposed to alcohol (100 mM), nicotine (10 microM), or both alcohol and nicotine for 24, 48, 72, or 96 h. Caspase-3 activity and DNA fragmentation, markers for apoptotic cell death, were measured to determine the role of apoptosis in mediating decreases in PC12 cell numbers. The findings indicated that both alcohol and nicotine exposure significantly decreased PC12 cell numbers when compared with the control treatment. Furthermore, the coexposure of these two drugs caused a significantly greater decrease in cell numbers when compared with cells exposed to either alcohol or nicotine alone. This additive effect was related to the duration of exposure with a marked reduction in cell numbers following 96 h of coexposure to alcohol and nicotine. Neither alcohol nor nicotine exposure appeared to alter caspase-3 activity or DNA fragmentation levels, suggesting that the reduction in PC12 cell numbers following alcohol and/or nicotine exposure may possibly be due to factors other than apoptosis, such as interference with proliferation rates.

Neonatal alcohol exposure increases malondialdehyde (MDA) and glutathione (GSH) levels in the developing cerebellum.

It has been suggested that developmental alcohol-induced brain damage is mediated through increases in oxidative stress. In this study, the concentrations of malondialdehyde (MDA) and reduced glutathione (GSH) were measured to indicate alcohol-mediated oxidative stress. In addition, the ability of two known antioxidants, melatonin (MEL) and lazaroid U-83836E (U), to attenuate alcohol-induced oxidative stress was investigated. Sprague-Dawley rat pups were randomly assigned to six artificially-reared groups, ALC (alcohol), MEL, MEL/ALC, U, U/ALC, and GC (gastrostomy control), and one normal suckle control (to control for artificial-rearing effects on the dependent variables). The daily dosages for ALC, MEL, and U were 6 g/kg, 20 mg/kg, and 20 mg/kg, respectively. Alcohol was administered in 2 consecutive feedings, and antioxidant (MEL or U) was administered for a total of 4 consecutive feedings (2 feedings prior to and 2 feedings concurrently with alcohol). The animals received treatment from postnatal days (PD) 4 through 9. Cerebellar, hippocampal, and cortical samples were collected on PD 9 and analyzed for MDA and GSH content. The results indicated that MDA concentrations in the cerebellum were significantly elevated in animals receiving alcohol; however, MDA levels in the hippocampus and cortex were not affected by alcohol treatment. Additionally, GSH levels in the cerebellum were significantly elevated in groups receiving alcohol, regardless of antioxidant treatment. Neither antioxidant was able to protect against alcohol-induced alterations of MDA or GSH. These findings suggest that alcohol might increase GSH levels indirectly as a compensatory mechanism designed to protect the brain from oxidative-stress-mediated insult.

Effect of prenatal or perinatal nicotine exposure on neonatal thyroid status and offspring growth in rats.

Smoking during pregnancy causes intrauterine growth retardation and low birth weight of the offspring. However, it is unclear whether nicotine, rather than other compounds from a cigarette, would mediate long-term growth retardation. There is a body of evidence suggesting that optimal thyroid status is important for the normal development of the fetus. Therefore, these studies examined whether developmental nicotine exposure would interfere with the growth of the offspring and alter the thyroid status of neonates. Pregnant Sprague-Dawley rats were given 0, 15 or 25 mg nicotine pellets throughout pregnancy. Some offspring continued to receive 1 or 2 mg/kg/day nicotine during early postnatal period. The remaining offspring received no further treatment after birth. The body weight of all offspring was monitored until adulthood. Additionally, the neonatal thyroid status from all treatment groups was assessed from the serum of 10-day-old pups. Regardless of the timing of nicotine exposure, the nicotine treatment significantly increased the body weight in female offspring starting on postnatal day (PD) 35 and such an increase persisted into adulthood (PD 91). However, this nicotine exposure paradigm led to a transient increase in male offspring body weight on PD 35. Furthermore, current nicotine exposure regimens did not alter the total T4 level, T3 uptake and the calculated Free T4 index. The present findings are in agreement with some clinical studies reporting a higher body weight among children born to mothers who smoked during pregnancy. Furthermore, the data on thyroid status suggest that cigarette smoking-induced alterations in thyroid status might be mediated through compounds in cigarettes other than nicotine.

Long-term effects of neonatal alcohol exposure on photic reentrainment and phase-shifting responses of the activity rhythm in adult rats.

In rats, neonatal alcohol (EtOH) exposure coinciding with the period of rapid brain growth produces structural damage in some brain regions that often persists into adulthood and thus may have long-term consequences in the neural regulation of behavior. Because recent findings indicate that the circadian clock located in the rat suprachiasmatic nucleus is vulnerable to alcohol-induced insults during development, the present study examined the long-term effects of neonatal alcohol exposure on the photic regulation of circadian behavior in adult rats. Rat pups were exposed to alcohol (3.0, 4.5, or 6.0 g x kg(-1) x day(-1)) or isocaloric milk formula on postnatal days 4-9 using artificial-rearing methods. At 2 months of age, animals were housed individually and circadian wheel-running behavior was continuously analyzed to determine the effects of neonatal alcohol treatment on the rate of reentrainment to a 6-h advance in the 12-h light:12-h dark photoperiod and the phase-shifting properties of free-running rhythms in response to discrete light pulses on a background of constant darkness. For all doses, neonatal alcohol exposure had a significant effect in reducing the time for reentrainment such that EtOH-treated rats required four to five fewer days than control animals for stable realignment of the activity rhythm to the shifted light-dark cycle. Coupled with the accelerated rate of reentrainment, the amplitude of light-evoked phase delays at circadian time 14 and advances at circadian time 22 in the 4.5 and 6.0 g x kg(-1) x day(-1) EtOH groups was almost twofold greater than that observed in control animals. The present observations indicate that the mechanisms by which photic signals regulate circadian behavior are permanently altered following alcohol exposure during the period of rapid brain development. These long-term alterations in the photic regulation of circadian rhythms may account, at least partially, for some neurobehavioral consequences of prenatal alcohol exposure in humans such as depression.

Gender-related response in open-field activity following developmental nicotine exposure in rats.

Smoking during pregnancy may lead to low birthweight and behavioral alterations in the offspring. In this study, the effects of developmental nicotine exposure on the somatic growth of the offspring and the behavioral performance in the open-field test were examined. Sprague-Dawley female rats were implanted with nicotine (35 mg for 21-day time release; NIC 35) or placebo pellets on gestational day (GD) 8 (postblastocyst implantation). A normal control group with no pellet implant was also included. There was a significantly higher maternal weight gain in the placebo group possibly due to a larger litter size. However, there were no significant differences in body weights among all three treatment groups for male and female offspring. The amount of activity, measured by the total number of crossings in the open-field test, indicated a gender difference in baseline level and pattern of ambulatory activity, with less activity (lower number of crossings) in male offspring and an increase in the activity of the female offspring as a function of testing day. The increase in the ambulatory activity of the female offspring was observed in the placebo and normal, but not the NIC 35 group suggesting that developmental nicotine exposure interferes with open-field activity, and this behavioral alteration is gender related.

Prenatal nicotine exposure does not cause Purkinje cell loss in the developing rat cerebellar vermis.

Smoking by pregnant women poses a potential risk on the unborn child because nicotine can easily be transported from the maternal to the fetal physiological system. Our previous studies have shown that developing brains are sensitive to nicotine-induced cell loss if nicotine was administered during the brain growth spurt (early postnatal) in a rat model system. The purpose of this study was to examine whether nicotine exposure prenatally (first two trimesters equivalent in rats) would lead to Purkinje cell loss in the developing cerebellar vermis. Pregnant female rats were subcutaneously implanted with 0 (placebo), 15 (NIC 15), or 25 (NIC 25) mg nicotine pellets (21-day time released) on gestational day (GD) 0. An additional control group receiving no implantation was also introduced (normal). One pup from each litter was sacrificed on postnatal day (PD) 10 and the cerebellar vermis was processed for stereological cell counting of Purkinje cells. No significant effects of prenatal nicotine treatment were found in the forebrain, cerebellum, and brainstem weights. Similarly, the assessments of volume, Purkinje cell number, and Purkinje cell density found no significant differences among all treatment groups. Taken together, the current and a previous finding, it suggests that there is a temporal window of vulnerability to nicotine-induced Purkinje cell loss in the developing cerebellar vermis.

Developmental alcohol exposure disrupts circadian regulation of BDNF in the rat suprachiasmatic nucleus.

In rats, damage to neuronal populations in some brain regions occurs in response to neonatal alcohol exposure coinciding with the period of rapid brain growth. These alcohol-induced defects in brain development may persist into adulthood and thus have long-term implications for the functional characteristics of damaged neuronal populations. The present study examined the effects of neonatal alcohol exposure on endogenous rhythmicity of the circadian clock located in the rat suprachiasmatic nucleus (SCN). Specifically, experiments were conducted to determine whether neonatal alcohol exposure alters the circadian rhythm of brain-derived neurotrophic factor (BDNF) content in the rat SCN because this neurotrophin is an important rhythmic output from the SCN clock. Male rat pups were exposed to alcohol (4.5 g/kg/day) or isocaloric milk formula on postnatal days 4-9 using artificial rearing methods. At 5-6 months of age, SCN and hippocampal tissue was harvested and subsequently examined for content of BDNF protein. Time-dependent fluctuations in BDNF protein levels were assessed by enzyme-linked immunosorbent assay (ELISA). In alcohol-treated rats, SCN levels of BDNF were significantly decreased and were characterized by a loss of circadian rhythmicity relative to those observed in control animals. In comparison, hippocampal levels of BDNF displayed no evidence of circadian regulation in all three treatment groups, but were slightly lower in alcohol-treated animals than in control groups. Importantly, these observations suggest that alcohol exposure during the period of rapid brain development may cause permanent changes in the SCN circadian clock.

Long-term nicotine exposure reduces Purkinje cell number in the adult rat cerebellar vermis.

Nicotine affects functions of the central nervous system. A previous study showed that developing cerebellar Purkinje cells are targets for early postnatal nicotine exposure. In this study, we assessed the effects of long-term nicotine exposure on mature cerebellar Purkinje cells. This is particularly relevant since the majority of smokers are exposed to nicotine over a long period. Female adult Sprague-Dawley rats received three doses of nicotine (0.01%, 0.03%, or 0.06%) through their sole water source. After 8 weeks of nicotine exposure, the cerebellar vermis was removed and processed for stereological cell counting. The results showed that this long-term nicotine treatment did not change the cerebellum weight or the size (volume) of the cerebellar vermis. The long-term nicotine treatment regimen did result in a significant loss of mature Purkinje cells in the cerebellum, however, such a loss of Purkinje cells was not nicotine dose-related. These findings indicated that the mature adult cerebellum is susceptible to the damaging effects of nicotine in depleting Purkinje cells in the cerebellum.

Phosphate-enhanced cytotoxicity of zinc oxide nanoparticles and agglomerates.

Zinc oxide (ZnO) nanoparticles (NPs) have been found to readily react with phosphate ions to form zinc phosphate (Zn3(PO4)2) crystallites. Because phosphates are ubiquitous in physiological fluids as well as waste water streams, it is important to examine the potential effects that the formation of Zn3(PO4)2 crystallites may have on cell viability. Thus, the cytotoxic response of NIH/3T3 fibroblast cells was assessed following 24h of exposure to ZnO NPs suspended in media with and without the standard phosphate salt supplement. Both particle dosage and size have been shown to impact the cytotoxic effects of ZnO NPs, so doses ranging from 5 to 50 µg/mL were examined and agglomerate size effects were investigated by using the bioinert amphiphilic polymer polyvinylpyrrolidone (PVP) to generate water-soluble ZnO ranging from individually dispersed 4 nm NPs up to micron-sized agglomerates. Cell metabolic activity measures indicated that the presence of phosphate in the suspension media can led to significantly reduced cell viability at all agglomerate sizes and at lower ZnO dosages. In addition, a reduction in cell viability was observed when agglomerate size was decreased, but only in the phosphate-containing media. These metabolic activity results were reflected in separate measures of cell death via the lactate dehydrogenase assay. Our results suggest that, while higher doses of water-soluble ZnO NPs are cytotoxic, the presence of phosphates in the surrounding fluid can lead to significantly elevated levels of cell death at lower ZnO NP doses. Moreover, the extent of this death can potentially be modulated or offset by tuning the agglomerate size. These findings underscore the importance of understanding how nanoscale materials can interact with the components of surrounding fluids so that potential adverse effects of such interactions can be controlled.

The role of cortisol in chronic binge alcohol-induced cerebellar injury: Ovine model.

Women who drink alcohol during pregnancy are at high risk of giving birth to children with neurodevelopmental disorders. Previous reports from our laboratory have shown that third trimester equivalent binge alcohol exposure at a dose of 1.75 g/kg/day results in significant fetal cerebellar Purkinje cell loss in fetal sheep and that both maternal and fetal adrenocorticotropin (ACTH) and cortisol levels are elevated in response to alcohol treatment. In this study, we hypothesized that repeated elevations in cortisol from chronic binge alcohol are responsible at least in part for fetal neuronal deficits. Animals were divided into four treatment groups: normal control, pair-fed saline control, alcohol and cortisol. The magnitude of elevation in cortisol in response to alcohol was mimicked in the cortisol group by infusing pregnant ewes with hydrocortisone for 6 h on each day of the experiment, and administering saline during the first hour in lieu of alcohol. The experiment was conducted on three consecutive days followed by four days without treatment beginning on gestational day (GD) 109 until GD 132. Peak maternal blood alcohol concentration in the alcohol group was 239 ± 7 mg/dl. The fetal brains were collected and processed for stereological cell counting on GD 133. The estimated total number of fetal cerebellar Purkinje cells, the reference volume and the Purkinje cell density were not altered in response to glucocorticoid infusion in the absence of alcohol. These results suggest that glucocorticoids independently during the third trimester equivalent may not produce fetal cerebellar Purkinje cell loss. However, the elevations in cortisol along with other changes induced by alcohol could together lead to brain injury seen in the fetal alcohol spectrum disorders.

Different patterns of regional Purkinje cell loss in the cerebellar vermis as a function of the timing of prenatal ethanol exposure in an ovine model.

Studies in rat models of fetal alcohol spectrum disorders have indicated that the cerebellum is particularly vulnerable to ethanol-induced Purkinje cell loss during the third trimester-equivalent, with striking regional differences in vulnerability in which early-maturing regions in the vermis show significantly more loss than the late-maturing regions. The current study tested the hypothesis that the sheep model will show similar regional differences in fetal cerebellar Purkinje cell loss when prenatal binge ethanol exposure is restricted to the prenatal period of brain development equivalent to the third trimester and also compared the pattern of loss to that produced by exposure during the first trimester-equivalent. Pregnant Suffolk sheep were assigned to four groups: first trimester-equivalent saline control group, first trimester-equivalent ethanol group (1.75 g/kg/day), third trimester-equivalent saline control group, and third trimester-equivalent ethanol group (1.75 g/kg/day). Ethanol was administered as an intravenous infusion on 3 consecutive days followed by a 4-day ethanol-free interval, to mimic a weekend binge drinking pattern. Animals from all four groups were sacrificed and fetal brains were harvested on gestation day 133. Fetal cerebellar Purkinje cell counts were performed in an early-maturing region (lobules I-X) and a late-maturing region (lobules VIc-VII) from mid-sagittal sections of the cerebellar vermis. As predicted, the third trimester-equivalent ethanol exposure caused a significant reduction in the fetal cerebellar Purkinje cell volume density and Purkinje cell number in the early-maturing region, but not in the late-maturing region. In contrast, the first trimester-equivalent ethanol exposure resulted in significant reductions in both the early and late-maturing regions. These data confirmed that the previous findings in rat models that third trimester-equivalent prenatal ethanol exposure resulted in regionally-specific Purkinje cell loss in the early-maturing region of the vermis, and further demonstrated that first trimester ethanol exposure caused more generalized fetal cerebellar Purkinje cell loss, independent of the cerebellar vermal region. These findings support the idea that prenatal ethanol exposure in the first trimester interferes with the genesis of Purkinje cells in an unselective manner, whereas exposure during the third trimester selectively kills post-mitotic Purkinje cells in specific vermal regions during a vulnerable period of differentiation and synaptogenesis.

Amphetamine treatment during early postnatal development transiently restricts somatic growth.

AIMS: Restricted somatic growth during fetal or early postnatal periods has been suggested to serve as a predictive indicator for neuroanatomical changes and behavioral impairments during adulthood. Here, the effects of d-amphetamine sulfate (AMPH) exposure during the brain growth spurt period on this potential indicator were evaluated. MAIN METHODS: Rats received 0, 5, 15 or 25mg/kg/day of AMPH via two daily intragastric intubations from PD4-9. Body weight data were collected every other day from PD1 to 21, and then weekly until PD59. On PD9, a subset of animals was terminated 90min after the last amphetamine treatment and the weights of the cortex, cerebellum, and brainstem were collected. Weights of these brain regions from young adult rats were also assessed on PD68. KEY FINDINGS: AMPH exposure during early postnatal development limited somatic growth in a dose-related manner, with significantly lower body weights in animals assigned to the AMPH 25 and AMPH 15 groups. However, this was transient in nature, with no significant difference in weight observed after pups were weaned on PD21. Further, no differences in brain weight were observed at either age as a result of AMPH exposure. SIGNIFICANCE: These findings support the idea that developmental AMPH exposure transiently restricts somatic growth. Moreover, the lack of effect on brain weight shows that AMPH differentially affects somatic and brain growth. The current findings suggest that in addition to the immediate effects on body weight, amphetamine may alter the rate of growth, and increase the risk for weight-related adult diseases.