Postnatal Alcohol Exposure Research Articles

The role of JAK/STAT/SOCS3 signaling in rats with brain damage induced by early alcohol exposure after birth

AbstractEarly postnatal alcohol exposure can have negative impacts on neonatal rat brain development and function. Our research explored the impacts of alcohol exposure from postnatal day 4 to PD9 on Sprague‒Dawley rat pups. Pups were intragastrically administered with either an alcohol milk solution or a pure milk solution twice daily. On PD10, brains were analyzed via histological and biochemical methods. Alcohol exposure led to growth impairment, behavioral abnormalities, and cognitive deficits. It also reduced microglial numbers in the hippocampus while activating the remaining microglia to secrete IL‐6. In addition, alcohol induced the upregulation of pro‐apoptotic factors and downregulation of the anti‐apoptotic protein BCL‐2 in the hippocampus by activating the JAK/STAT/SOCS3 signaling pathway. Similar effects were observed in vitro when BV‐2 cells were exposed to ethanol and HT‐22 cells were exposed to IL‐6. The drug AG490, a STAT3 inhibitor, mitigated IL‐6‐induced JAK/STAT activation and neuronal apoptosis in HT‐22 cells. Overall, these findings demonstrate that early‐life alcohol exposure triggers an inflammatory microglial response involving the release of IL‐6, which activates JAK/STAT signaling, leading to hippocampal neuronal apoptosis and developmental/cognitive impairments. AG490 may disrupt this inflammatory signaling cascade and cause neuronal damage.

Fetal Alcohol-Related Postnatal Growth Restriction Is Independent of Infant Feeding Practices and Postnatal Alcohol Exposure in a Prospective South African Birth Cohort

Prenatal alcohol exposure (PAE) causes growth restriction that worsens in the first year of life. However, the roles of postnatal nutrition in fetal alcohol growth restriction and the impact of postnatal alcohol exposure via breastmilk on growth remain unknown. We aimed to compare infant feeding practices during the first 6.5 months of life between heavy drinkers and abstainers/light drinkers, to examine whether these practices play confounding roles in fetal alcohol growth restriction, and to determine the impact of postnatal alcohol exposure via breastmilk on growth. Eighty-seven heavy-drinking pregnant women and 71 abstainers/light drinkers (controls) were recruited prenatally from antenatal clinics in Cape Town, South Africa. Demographic background and alcohol, cigarette, marijuana, and methamphetamine use during pregnancy were assessed pre- and postnatally. Infant feeding practices were assessed at 6.5 months postpartum using the USDA Infant Feeding Questionnaire. Infant weight, length, and head circumference were measured at 2 weeks, 6.5 and 12 months, and 5 years. Neither prenatal nor postnatal alcohol consumption was related to the duration of breastfeeding, exclusive breastfeeding, exclusive formula, or mixed feeding. Complementary feeding practices were remarkably similar between exposure groups. PAE was related to all postnatal anthropometry measures at all age points, independent of infant feeding practices. Postnatal alcohol exposure via breastmilk was unrelated to any anthropometry outcome after control for PAE. In conclusion, fetal alcohol-related postnatal growth restriction was not attributable to differences in postnatal infant feeding practices or postnatal alcohol exposure and is thus likely a direct teratogenic effect of PAE.

The investigation of the effects of postnatal alcohol exposure on molecular content and antioxidant capacity of mice liver tissue

One of the most common causes of fetal alcohol spectrum disease (FASD) characterized with neurodevelopmental disorder and growth retardation, is the postnatal alcohol consumption. Since studies in literature are mainly focused on alcohol-induced effects on brain tissues, the molecular effects of postnatal alcohol consumption on fetal liver are not clarified yet. The aim of this study is to determine the postnatal alcohol consumption-induced structural and compositional changes on liver tissue and the antioxidant capacity of liver. Newborn mice were divided into 3 groups as control group without any treatment, alcohol group treated with 3.0 g/kg of ethanol in 0.02 ml/g of artificially enriched milk between Postnatal Days (PD) 3–20 and intragastric intubation control group which was intragastrically intubated in the same method as the alcohol group but without ethanol/milk. These postnatal days in mice refers prenatal period (third trimester) of gestation in human. The biomolecular changes were determined by ATR-FTIR spectral analysis of the samples, besides the biochemical measurement of total protein content and antioxidant capacity of liver tissue. The result of the current study shows that while there was a slight increase in total lipid content, significant decrease in unsaturated lipid and total protein contents and total antioxidant capacity of liver were observed in alcohol-treated group. Thus, it is concluded that postnatal alcohol treatment causes significant changes in tissue proteins and lipids by inducing lipid peroxidation and changes in protein conformations of the liver tissue. In addition to that alcohol consumption also reduce the antioxidant capacity of liver tissue.

Influence of Maternal Choline Supplementation on Metabolic Outcomes of Offspring With Prenatal and Postnatal Alcohol Exposures

ObjectivesPrenatal alcohol exposure (PAE) affects cognitive development. However, it is unclear whether PAE influences metabolic health of offspring and whether postnatal alcohol intake would exacerbate metabolic deterioration resulting from PAE. Choline is a semi-essential nutrient that has been demonstrated to mitigate the cognitive impairment of PAE. This study investigated how maternal choline supplementation may modify metabolic health of offspring with prenatal and postnatal alcohol exposures.MethodsC57BL/6J female mice were fed either a Lieber DeCarli liquid diet with 1.4% ethanol between embryonic day (E) 9.5 and E17.5 or a control Lieber DeCarli diet. Choline was supplemented to 4 x concentrations versus control throughout pregnancy. At postnatal week 7, offspring mice were exposed to 1.4% ethanol for females and 3.9% ethanol for males for 4 weeks.ResultsPostnatal alcohol exposure led to lower weight gain of offspring regardless of PAE status. There were no differences in glucose tolerance by pre or postnatal alcohol exposure, yet prenatal choline supplementation led to better glucose tolerance in male offspring. Postnatal alcohol exposure led to lower expression of carnitine palmitoyltransferase 1a (Cpt1a), an important enzyme that mediates fatty acid β-oxidation, but prenatal choline supplementation prevented this alteration.ConclusionsIn the current model, PAE does not seem to exacerbate metabolic differences triggered by postnatal alcohol exposure. Maternal choline supplementation has a modest effect on normalizing liver metabolic gene expression that is altered by alcohol exposure.Funding SourcesPSC-CUNY.

Metabolic-Epigenetic Exchange During Pre- and Postnatal Alcohol Exposure

Emerging evidence suggests that metabolic-epigenetic interactions play an important role in the regulation of complex behaviors. Neuronal histone acetylation, for example, relies on acetyl-CoA produced from acetate by chromatin-bound acetyl-CoA synthetase 2 (ACSS2). Alcohol metabolism is a major source of acetate. Brain histone acetylation may thus be under the influence of alcohol.

Postnatal alcohol exposure and adolescent exercise have opposite effects on cerebellar microglia in rat.

Developmental alcohol exposure results in altered neuroimmune function in both humans and rodents. Given the critical role for the principle neuroimmune cell, microglia, in maintaining synaptic form and function, microglial dysfunction in the cerebellum may be an important mechanism underlying the aberrant cerebellar connectivity observed in rodent models of fetal alcohol spectrum disorders. Using an established rodent model of alcohol exposure during human third-trimester fetal development, we examine the cerebellum of male and female Long Evans rats to determine the impact of early postnatal alcohol exposure on cerebellar microglia, and the potential therapeutic effects of an adolescent intervention consisting of voluntary exercise (running). All cerebelli were examined at postnatal day 42 (i.e., late adolescence), and microglia were labeled with Iba1, a microglia-specific protein. Early postnatal alcohol exposure caused an increase in microglial density throughout cerebellum and a reduction in cerebellar volume, and a reduction in the proportion of fully ramified (often called "resting state") microglia selective to lobules 1-4. In contrast, adolescent exercise decreased microglial density throughout cerebellum and increased cerebellar volume, while activating microglia (as indicated by increases in amoeboid microglia, and reductions in fully and partially ramified microglia) selectively in lobules 1-4. These results suggest that adolescent exercise may be a suitable intervention to ameliorate alcohol-induced neuroimmune dysfunction as it alters microglia density and cerebellar volume in opposite to the effects of developmental alcohol exposure. Importantly, exercise intervention can be flexibly implemented well after the time window of vulnerability to alcohol.

Brainstem expression of SLC6A4, HTR2C, NGF, BDNF, TRKANGF, TRKBBDNF and P75NTR following paternal alcohol exposure in the male mouse

We previously showed in the mouse that paternal preconception alcohol exposure (PPAE) affects alcohol sensitivity by analyzing postnatal alcohol preference in the offspring. In this mouse study by using the same animals of the previous investigation we aimed at examining whether or not PPAE may disrupt the epigenetic regulation of postnatal alcohol sensitivity in the offspring by investigating pathways regulating mood, emotion, serotonergic tone and neurotrophins such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). We analyzed the brainstem gene expression of serotonin transporter Solute Carrier Family 6 Member4 (SLC6A4), 5-Hydroxytryptamine Receptor 2C (HTR2C) binding the neurotransmitter serotonin, and NGF, BDNF and their tropomyosin receptor kinase A (TrkANGF) and B (TrKBBDNF) (high-affinity NGF and BDNF receptors) and p75NTR (low-affinity, pan-neurotrophins receptor) in adult offspring that underwent or not postnatal alcohol exposure. We found SLC6A4 elevation and decreased HTR2C in the offspring of chronic alcohol-exposed sires. We also disclosed p75NTR elevation in the offspring of chronically exposed sires as well as postnatal sensitization to low alcohol doses in the offspring of chronically exposed sires for both TrKBBDNF and BDNF. In our PPAE mouse model, where genotype effects can be carefully measured, we observed that the sires’ exposure to alcohol before mating might disrupt the sensitivity to the serotonergic/neurotrophic-associated effects of alcohol influencing the postnatal alcohol preference in the offspring.

Single-day Postnatal Alcohol Exposure Induces Apoptotic Cell Death and Causes long-term Neuron Loss in Rodent Thalamic Nucleus Reuniens

Fetal alcohol spectrum disorders (FASD) constitute a prevalent, yet preventable, developmental disorder worldwide. While a wealth of research demonstrates that altered function of hippocampus (HPC) and prefrontal cortex may underlie behavioral impairments in FASD, only one published paper to date has examined the impact of developmental alcohol exposure (AE) on the region responsible for coordinated prefrontal–hippocampal activity: thalamic nucleus reuniens (Re). In the current study, we used a rodent model of human third trimester AE to examine both the acute and lasting impact of a single-day AE on Re. We administered 5.25 g/kg of ethanol to male and female Long Evans rat pups on postnatal day (PD) 7. We used unbiased stereological estimation to evaluate cell death or cell loss at three time points: 12 h after alcohol administration; 4 days after alcohol administration (i.e., PD11); in adulthood (i.e.,PD 72). AE on PD7 increased apoptotic cell death in Re on PD7, and caused short-term cell loss on PD11. This relationship between short-term cell death versus cell number suggests that alcohol-related cell loss is driven by induction of apoptosis. In adulthood, alcohol-exposed animals displayed permanent cell loss (mediating volume loss in the Re), which included a reduction in neuron number (relative to procedural controls). Both procedural controls and alcohol exposed animals displayed a deficit in non-neuronal cell number relative to typically-developing controls, suggesting that Re cell populations may be vulnerable to early life stress as well as AE in an insult- and cell type-dependent manner.

Prenatal and postnatal alcohol exposure increases vulnerability to cocaine addiction in adult mice.

Alcohol exposure in utero may lead to a wide range of long-lasting morphological and behavioural deficiencies known as fetal alcohol spectrum disorders (FASD), associated with a higher risk of later developing neuropsychiatric disorders. However, little is known about the long-term consequences of cocaine use and abuse in individuals with FASD. This study aimed to investigate the effects of maternal binge alcohol drinking during prenatal and postnatal periods on cocaine reward-related behaviours in adult offspring. Pregnant C57BL/6 female mice were exposed to an experimental protocol of binge alcohol consumption (drinking-in-the-dark test) from gestation to weaning. Male offspring were subsequently left undisturbed until reaching adulthood and were tested for cocaine-induced motivational responses (conditioned place preference, behavioural sensitization and operant self-administration). Protein expression of dopamine- and glutamate-related molecules was assessed following cocaine-induced reinstatement. The results show that prenatal and postnatal alcohol exposure enhanced the preference for the cocaine-paired chamber in the conditioned place preference test. Furthermore, early alcohol-exposed mice displayed attenuated cocaine-induced behavioural sensitization but also higher cocaine self-administration. Furthermore, alterations in glutamatergic excitability (GluA1/GluA2 ratio) and ΔFosB expression were found in the prefrontal cortex and the striatum of alcohol-exposed mice after cocaine-primed reinstatement. Our findings demonstrate that maternal binge-like alcohol consumption during gestation and lactation alters sensitivity to the reinforcing effects of cocaine in adult offspring mice. Together, such data suggest that prenatal and postnatal alcohol exposure may underlie an enhanced susceptibility of alcohol-exposed offspring to develop drug addiction later in adulthood.

Hydrogen Sulfide Attenuates the Neurotoxicity in the Animal Model of Fetal Alcohol Spectrum Disorders.

Fetal alcohol spectrum disorder (FASD), which is caused by prenatal alcohol exposure, can result in cell death in specific brain regions. Alcohol-induced neurocognitive defects offspring's are included with activation of oxidative-inflammatory cascade followed with wide apoptotic neurodegeneration in many brain's regions such as hippocampus. According to the latest studies, H2S (hydrogen sulfide) can protect neuronal cells via antioxidant, anti-inflammatory, and anti-apoptotic mechanisms in different animal models. Therefore, we aimed to evaluate the protective effects of H2S on ethanol-induced neuroinflammation and neuronal apoptosis in pup hippocampus with postnatal alcohol exposure. Administration of ethanol (5.27g/kg) in milk solution (27.8mL/kg) for each rat pups was performed through intragastric intubation on 2 to 10 postnatal days and NaHS as H2S donor (1mg/kg) was injected on similar time, subcutaneously. For examining the antioxidant and anti-inflammatory effects, ELISA assay was performed to determine the levels of TNF-α, IL1β, and antioxidant enzymes. Immunohistochemical staining was performed to evaluate the expression levels of GFAP and caspase-3 also Nissl staining was done for necrotic cell death evaluation. H2S treatment could significantly increase the activity of total superoxide dismutase, catalase, and glutathione (P < 0.05). It also decreased the levels of TNF-α, IL1β, and malondialdehyde, compared with the ethanol group (P < 0.05). Moreover, the number of hippocampal caspase-3, GFAP-positive cells, and necrotic cells death reduced in the H2S group (P< 0.01). Based on the findings, H2S can inhibit apoptotic signaling that is mediated by the oxidative-inflammatory cascade following ethanol exposure of rat pups on postnatal period.

Nesfatin-1 Ameliorate Learning and Memory Deficit via Inhibiting Apoptosis and Neuroinflammation Following Ethanol-Induced Neurotoxicity in Early Postnatal Rats

Fetal exposure to alcohol can cause a wide range of long-lasting physiological and behavioral effects, collectively referred to as fetal alcohol spectrum disorders (FASD). Neurocognitive disorders caused by alcohol in children are linked to activation of oxidative-inflammatory cascade and a high level of apoptotic neurodegeneration in several brain regions, such as hippocampus. NCB2/nesfatin-1 is a novel identified anorexigenic peptide. In addition recently, it has been reported as anti-apoptotic and anti-inflammatory properties of nesfatin-1 under both in vitro and in vivo situations. This research aimed at evaluating the protective activities of nesfatin-1 on ethanol-induced neuroinflammation and neuronal apoptosis in rat hippocampus with postnatal alcohol exposure. Administration of 5.27 g/kg of ethanol in milk solution 27.8 mL/kg to male rat pups was performed through intragastric intubation on postnatal days 2–10. The pups were administered 5 and 10 µg/kg of nesfatin-1 on postnatal days 2–10. For examining the spatial memory, Morris water maze test was carried out 36 days after birth. Following the behavioral test, immunohistochemical staining was performed to evaluate the expression levels of GFAP and apoptotic cell death was detected by TUNEL staining, also ELISA assay was done for measuring TNF-α, and antioxidant enzymes levels. Nesfatin-1 treatment could significantly improve spatial memory impairment (P < 0.01). Also it could significantly increase the activity of total SOD and GSH-Px (P < 0.05). Nesfatin-1 treatment caused a decrease in TNF-α and MDA levels, than the ethanol group (P < 0.01). Also it reduced the hippocampal apoptotic cells death, and GFAP-positive cells (P < 0.01). Based on the findings, apoptotic signaling mediated by the oxidative-inflammatory cascade is inhibited by nesfatin-1 in rat pups with ethanol exposure in the postnatal period.

Hydrogen sulfide improves spatial memory impairment via increases of BDNF expression and hippocampal neurogenesis following early postnatal alcohol exposure

According to experimental and clinical findings, fetal brain development may be interrupted by maternal alcohol consumption during pregnancy. Adult hippocampal neurogenesis is thought to play a role in cognition function (i.e. learning and memory). Recent evidence suggests that ethanol administration causes major apoptotic neurodegeneration in many regions of the rats’ developing brain during the synaptogenesis period. Based on the recent studies, H2S improve learning and memory via increased neurogenesis and antiapoptotic mechanisms in different animal models. In this study, we aimed to evaluate the protective effects of hydrogen sulfide on alcohol-induced memory impairment, hippocampus neurogenesis and neuronal apoptosis in rat pups with postnatal ethanol exposure.Administration of ethanol to male rat pups was performed through intragastric intubation on postnatal days 2–10. The pups were administered 1 mg/kg of NaHS (H2S donor) on postnatal days 2–10. For examining the spatial memory, Morris water maze test was carried out 36 days after birth. Following the behavioral test, immunohistochemical staining was performed to evaluate the expression levels of BrdU, BDNF and Apoptotic cell death was detected by TUNEL staining.Hydrogen sulfide (H2S) treatment could significantly improve spatial memory impairment (P < 0.05) and significantly increase the expression of BrdU and BDNF in dentate gyrus area (P < 0.05). It also decreased positive TUNEL cells, compared with the ethanol group (P < 0.01).Based on the findings, H2S makes significant neuroprotective effects on Ethanol neurotoxicity due to its neurogenesis and anti-apoptotic activity.

Pre- and postnatal alcohol exposure delays, in female but not in male rats, the extinction of an auditory fear conditioned memory and increases alcohol consumption.

Repeated exposure to alcohol increases retrieval of fear-conditioned memories, which facilitates, among other factors, the emergence of post-traumatic stress disorder (PTSD). Individuals with PTSD are more likely to develop alcohol and substance abuse related disorders. We assessed if prenatal and early postnatal alcohol exposure (PAE) increased the susceptibility to retain aversive memories and if this was associated with subsequent heightened alcohol consumption. Pregnant Sprague-Dawley rats were exposed for 22hr/day, throughout pregnancy and until postnatal Day 7 to a single bottle of sucralose - sweetened 10% alcohol solution (PAE Group), or to a single bottle of tap water and sucralose (Control Group). Auditory fear conditioning (AFC) was performed in the adolescent offspring at postnatal Day 40. Freezing was measured during acquisition, retention and extinction phases, followed by 3weeks of free choice alcohol intake. Female, but not male, PAE rats exhibited impaired extinction of the aversive memory, a finding associated with higher levels of 3-4 Dihidroxyphenylacetic acid (DOPAC) in the nucleus accumbens and heightened alcohol intake, respect to controls. These findings suggest that PAE makes females more vulnerable to long-term retention of aversive memories, which coexist with heightened alcohol intake. These findings are reminiscent of those of PTSD.

Nucleus reuniens of the midline thalamus of a rat is specifically damaged after early postnatal alcohol exposure.

Individuals diagnosed with fetal alcohol spectrum disorders often show behavioral impairments in executive functioning. Mechanistic studies have implicated coordination between the prefrontal cortex and the hippocampus (through thalamic nucleus reuniens) as essential for such executive functions. This study is the first to report the long-term neuroanatomical alterations to the ventral midline thalamus after alcohol exposure on postnatal days 4-9 (a rodent model of binge drinking during the third-trimester of human pregnancy). Alcohol added to a milk formula was administered to female Long-Evans rat pups on postnatal days 4-9 (5.25 g/kg/day of ethanol, intragastric intubation). Control animals were intubated without the administration of liquid. In adulthood, brains were immunohistochemically labeled for a neuronal marker (NeuN) conjugated with Cy3 fluorophore and stained with Hoechst33342 to visualize nuclei. Total non-neuronal cell number (NeuN/Hoechst) and neuron number (NeuN/Hoechst), and total volume were estimated using unbiased stereology in two neighboring midline thalamic nuclei: reuniens and rhomboid. Estimates were analyzed using linear mixed modeling to account for animal and litter as clustering variables. A 21% reduction in the total neuron number (resulting in altered neuron-to-non-neuron ratio) and an 18% reduction in total volume were found exclusively in thalamic nucleus reuniens in rats exposed to ethanol. Non-neuronal cell number was not changed in reuniens. No ethanol-induced changes on any measures were observed in rhomboid nucleus. These specific neuroanatomical alterations provide a necessary foundation for further examination of circuit-level alterations that occur in fetal alcohol spectrum disorder.

Altered brain functional connectivity and behaviour in a mouse model of maternal alcohol binge-drinking

Prenatal and perinatal alcohol exposure caused by maternal alcohol intake during gestation and lactation periods can have long-lasting detrimental effects on the brain development and behaviour of offspring. Children diagnosed with Foetal Alcohol Spectrum Disorders (FASD) display a wide range of cognitive, emotional and motor deficits, together with characteristic morphological abnormalities. Maternal alcohol binge drinking is particularly harmful for foetal and early postnatal brain development, as it involves exposure to high levels of alcohol over short periods of time. However, little is known about the long-term effects of maternal alcohol binge drinking on brain function and behaviour. To address this issue, we used pregnant C57BL/6 female mice with time-limited access to a 20% v/v alcohol solution as a procedure to model alcohol binge drinking during gestation and lactational periods. Male offspring were behaviourally tested during adolescence (30 days) and adulthood (60 days), and baseline neural metabolic capacity of brain regions sensitive to alcohol effects were also evaluated in adult animals from both groups. Our results show that prenatal and postnatal alcohol exposure caused age-dependent changes in spontaneous locomotor activity, increased anxiety-like behaviour and attenuated alcohol-induced conditioned place preference in adults. Also, significant changes in neural metabolic capacity using cytochrome c oxidase (CCO) quantitative histochemistry were found in the hippocampal dentate gyrus, the mammillary bodies, the ventral tegmental area, the lateral habenula and the central lobules of the cerebellum in adult mice with prenatal and postnatal alcohol exposure. In addition, the analysis of interregional CCO activity correlations in alcohol-exposed adult mice showed disrupted functional brain connectivity involving the limbic, brainstem, and cerebellar regions. Finally, increased neurogenesis was found in the dentate gyrus of the hippocampus of alcohol-exposed offspring, suggesting neuroadaptive effects due to early alcohol exposure. Our results demonstrate that maternal binge-like alcohol drinking causes long-lasting effects on motor and emotional-related behaviours associated with impaired neuronal metabolic capacity and altered functional brain connectivity.

Turnover of histones and histone variants in postnatal rat brain: effects of alcohol exposure

BackgroundAlcohol consumption during pregnancy is a significant public health problem and can result in a continuum of adverse outcomes to the fetus known as fetal alcohol spectrum disorders (FASD). Subjects with FASD show significant neurological deficits, ranging from microencephaly, neurobehavioral, and mental health problems to poor social adjustment and stress tolerance. Neurons are particularly sensitive to alcohol exposure. The neurotoxic action of alcohol, i.e., through ROS production, induces DNA damage and neuronal cell death by apoptosis. In addition, epigenetics, including DNA methylation, histone posttranslational modifications (PTMs), and non-coding RNA, play an important role in the neuropathology of FASD. However, little is known about the temporal dynamics and kinetics of histones and their PTMs in FASD.ResultsWe examined the effects of postnatal alcohol exposure (PAE), an animal model of human third-trimester equivalent, on the kinetics of various histone proteins in two distinct brain regions, the frontal cortex, and the hypothalamus, using in vivo 2H2O-labeling combined with mass spectrometry-based proteomics. We show that histones have long half-lives that are in the order of days. We also show that H3.3 and H2Az histone variants have faster turnovers than canonical histones and that acetylated histones, in general, have a faster turnover than unmodified and methylated histones. Our work is the first to show that PAE induces a differential reduction in turnover rates of histones in both brain regions studied. These alterations in histone turnover were associated with increased DNA damage and decreased cell proliferation in postnatal rat brain.ConclusionAlterations in histone turnover might interfere with histone deposition and chromatin stability, resulting in deregulated cell-specific gene expression and therefore contribute to the development of the neurological disorders associated with FASD. Using in vivo 2H2O-labeling and mass spectrometry-based proteomics might help in the understanding of histone turnover following alcohol exposure and could be of great importance in enabling researchers to identify novel targets and/or biomarkers for the prevention and management of fetal alcohol spectrum disorders.

The effects of postnatal alcohol exposure and galantamine on the context pre-exposure facilitation effect and acetylcholine efflux using in vivo microdialysis

Fetal alcohol spectrum disorders (FASD) are characterized by damage to multiple brain regions, including the hippocampus, which is involved in learning and memory. The acetylcholine neurotransmitter system provides major input to the hippocampus and is a possible target of developmental alcohol exposure. Alcohol (3.0 g/kg/day) was administered via intubation to male rat pups (postnatal day [PD] 2–10; ethanol-treated [ET]). Controls received a sham intubation (IC) or no treatment (NC). Acetylcholine efflux was measured using in vivo microdialysis (PD 32–35). ET animals were not different at baseline, but had decreased K+/Ca2+-induced acetylcholine efflux compared to NC animals and an enhanced acetylcholine response to galantamine (acetylcholinesterase inhibitor; 2.0 mg/kg) compared to both control groups. A separate cohort of animals was tested in the context pre-exposure facilitation effect task (CPFE; PD 30-32) following postnatal alcohol exposure and administration of galantamine (2.0 mg/kg; PD 11-30). Neither chronic galantamine nor postnatal alcohol exposure influenced performance in the CPFE task. Using immunohistochemistry, we found that neither alcohol exposure nor behavioral testing significantly altered the density of vesicular acetylcholine transporter or alpha7 nicotinic acetylcholine receptor in the ventral hippocampus (CA1). In the medial septum, the average number of choline acetyltransferase (ChAT+) cells was increased in ET animals that displayed the context-shock association; there were no changes in IC and NC animals that learned the context-shock association or in any animals that were in the control task that entailed no learning. Taken together, these results indicate that the hippocampal acetylcholine system is significantly disrupted under conditions of pharmacological manipulations (e.g., galantamine) in alcohol-exposed animals. Furthermore, ChAT was up‑regulated in ET animals that learned the CPFE, which may account for their ability to perform this task. In sum, developmental alcohol exposure may disrupt learning and memory in adolescence via a cholinergic mechanism.

Effects of postnatal alcohol exposure on hippocampal gene expression and learning in adult mice.

Fetal alcohol syndrome (FAS) is a condition resulting from excessive drinking by pregnant women. Symptoms of FAS include abnormal facial features, stunted growth, intellectual deficits and attentional dysfunction. Many studies have investigated FAS, but its underlying mechanisms remain unknown. This study evaluated the relationship between alcohol exposure during the synaptogenesis period in postnatal mice and subsequent cognitive function in adult mice. We delivered two injections, separated by 2 h, of ethanol (3 g/kg, ethanol/saline, 20% v/v) to ICR mice on postnatal day 7. After 10 weeks, we conducted a behavioral test, sacrificed the animals, harvested brain tissue and analyzed hippocampal gene expression using a microarray. In ethanol-treated mice, there was a reduction in brain size and decreased neuronal cell number in the cortex, and also cognitive impairment. cDNA microarray results indicated that 1,548 genes showed a > 2-fold decrease in expression relative to control, whereas 974 genes showed a > 2-fold increase in expression relative to control. Many of these genes were related to signal transduction, synaptogenesis and cell membrane formation, which are highlighted in our findings.

Repeated intermittent alcohol exposure during the third trimester-equivalent increases expression of the GABAA receptor δ subunit in cerebellar granule neurons and delays motor development in rats

Exposure to ethanol (EtOH) during fetal development can lead to long-lasting alterations, including deficits in fine motor skills and motor learning. Studies suggest that these are, in part, a consequence of cerebellar damage. Cerebellar granule neurons (CGNs) are the gateway of information into the cerebellar cortex. Functionally, CGNs are heavily regulated by phasic and tonic GABAergic inhibition from Golgi cell interneurons; however, the effect of EtOH exposure on the development of GABAergic transmission in immature CGNs has not been investigated. To model EtOH exposure during the 3rd trimester-equivalent of human pregnancy, neonatal pups were exposed intermittently to high levels of vaporized EtOH from postnatal day (P) 2 to P12. This exposure gradually increased pup serum EtOH concentrations (SECs) to ∼60 mM (∼0.28 g/dl) during the 4 h of exposure. EtOH levels gradually decreased to baseline 8 h after the end of exposure. Surprisingly, basal tonic and phasic GABAergic currents in CGNs were not significantly affected by postnatal alcohol exposure (PAE). However, PAE increased δ subunit expression at P28 as detected by immunohistochemical and western blot analyses. Also, electrophysiological studies with an agonist that is highly selective for δ-containing GABAA receptors, 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridine-3-ol (THIP), showed an increase in THIP-induced tonic current. Behavioral studies of PAE rats did not reveal any deficits in motor coordination, except for a delay in the acquisition of the mid-air righting reflex that was apparent at P15 to P18. These findings demonstrate that repeated intermittent exposure to high levels of EtOH during the equivalent of the last trimester of human pregnancy has significant but relatively subtle effects on motor coordination and GABAergic transmission in CGNs in rats.

O1 * FREE ORAL COMMUNICATIONS 1: BASIC NEUROBIOLOGICAL MECHANISMS OF ALCOHOL ADDICTION

O1 * FREE ORAL COMMUNICATIONS 1: BASIC NEUROBIOLOGICAL MECHANISMS OF ALCOHOL ADDICTION