Docosahexaenoic acid facilitates cell maturation and β-adrenergic transmission in astrocytes

Maternal omega-3 fatty acid deficiency affects fetal thermogenic development and postnatal musculoskeletal growth in mice

Maternal omega-3 (n-3) polyunsaturated fatty acids (PUFAs) deficiency can affect offspring's adiposity and metabolism by modulating lipid and glucose metabolism. However, the impact of n-3 PUFA deficiency on the development of fetal thermogenesis and its consequences is not reported. Using an n-3 PUFA deficient mice, we assessed fetal interscapular brown adipose tissue (iBAT), body fat composition, insulin growth factor-1 (IGF-1), glucose transporters (GLUTs), and expression of lipid storage & metabolic proteins in the offspring. The n-3 PUFA deficiency did not change the pups' calorie intake, organ weight, and body weight. However, the offspring's skeletal growth was altered due to excess fat to lean mass, reduced tibia & femur elongation, dysregulated IGF-1 in the mother and pups (P< .05). Localization of uncoupling protein 1 (UCP1) in iBAT exhibited a reduced expression in the deficient fetus. Further, UCP1, GLUT1, GPR120 were downregulated while FABP3, ADRP, GLUT4 expressions were upregulated in the BAT of the deficient offspring (P< .05). The deficiency decreased endogenous conversion of the n-3 LCPUFAs from their precursors and upregulated SCD1, FASN, and MFSD2A mRNAs in the liver (P< .05). An altered musculoskeletal growth in the offspring is associated with impaired browning of the fetal adipose, dysregulated thermogenesis, growth hormone, and expression of glucose and fatty acid metabolic mediators due to maternal n-3 PUFA deficiency. BAT had higher metabolic sensitivity compared to WAT in n-3 PUFA deficiency. Maternal n-3 PUFA intake may prevent excess adiposity by modulating fetal development of thermogenesis and skeletal growth dynamics in the mice offspring.

Maternal omega-3 intake differentially affects the endocannabinoid system in the progeny`s neocortex and hippocampus: Impact on synaptic markers

Omega-3 (n-3) polyunsaturated fatty acids (PUFA) and the endocannabinoid system (ECS) modulate several functions through neurodevelopment including synaptic plasticity mechanisms. The interplay between n-3PUFA and the ECS during the early stages of development, however, is not fully understood. This study investigated the effects of maternal n-3PUFA supplementation (n-3Sup) or deficiency (n-3Def) on ECS and synaptic markers in postnatal offspring. Female rats were fed with a control, n-3Def, or n-3Sup diet from 15 days before mating and during pregnancy. The cerebral cortex and hippocampus of mothers and postnatal 1-2 days offspring were analyzed. In the mothers, a n-3 deficiency reduced CB1 receptor (CB1R) protein levels in the cortex and increased CB2 receptor (CB2R) in both cortex and hippocampus. In neonates, a maternal n-3 deficiency reduced the hippocampal CB1R amount while it increased CB2R. Additionally, total GFAP isoform expression was increased in both cortex and hippocampus in neonates of the n-3Def group. Otherwise, maternal n-3 supplementation increased the levels of n-3-derived endocannabinoids, DHEA and EPEA, in the cortex and hippocampus and reduced 2-arachidonoyl-glycerol (2-AG) concentrations in the cortex of the offspring. Furthermore, maternal n-3 supplementation also increased PKA phosphorylation in the cortex and ERK phosphorylation in the hippocampus. Synaptophysin immunocontent in both regions was also increased. In vitro assays showed that the increase of synaptophysin in the n-3Sup group was independent of CB1R activation. The findings show that variations in maternal dietary omega-3 PUFA levels may impact differently on the ECS and molecular markers in the cerebral cortex and hippocampus of the progeny.

Perinatal Dietary Polyunsaturated Fatty Acids in Brain Development, Role in Neurodevelopmental Disorders

n-3 and n-6 polyunsaturated fatty acids (PUFAs) are essential fatty acids that are provided by dietary intake. Growing evidence suggests that n-3 and n-6 PUFAs are paramount for brain functions. They constitute crucial elements of cellular membranes, especially in the brain. They are the precursors of several metabolites with different effects on inflammation and neuron outgrowth. Overall, long-chain PUFAs accumulate in the offspring brain during the embryonic and post-natal periods. In this review, we discuss how they accumulate in the developing brain, considering the maternal dietary supply, the polymorphisms of genes involved in their metabolism, and the differences linked to gender. We also report the mechanisms linking their bioavailability in the developing brain, their transfer from the mother to the embryo through the placenta, and their role in brain development. In addition, data on the potential role of altered bioavailability of long-chain n-3 PUFAs in the etiologies of neurodevelopmental diseases, such as autism, attention deficit and hyperactivity disorder, and schizophrenia, are reviewed.

Growth Indices of Exclusively Breastfed Until 6 Months Age and Formula-Fed Infants in Southwest of Iran

Background:

Formula milk is prepared as a nutritional substitution for human breast milk, but because of biologic and constituent differences, it might cause obesity and growth disorders in infants. In this study, we compared the growth pattern of formula-fed and breastfed infants living in Yasuj, southwest of Iran.

Methods:

Infants 7–14 months of age in southwest of Iran were classified as exclusively breastfed (n = 200) and formula-fed (n = 200) in their first 6 months of life. Growth velocity and Z-scores of weight for age, length for age, weight for length, and head circumference were estimated using WHO Anthro Plus software (2010) and SPSS Version 19 (SPSS Inc., Chicago, IL, USA) using World Health Organization reference for growth data.

Results:

The study showed that Z-score of length for age and head circumference for age at the birth were significantly lower in formula-fed group than exclusively breastfed group (P < 0.05), but the Z-score of weight for length did not differ significantly. At the sixth month of age, Z-score of weight for length was significantly higher in formula-fed group (P < 0.05), but Z-score of length for age had no significant difference and Z-score of head circumference was higher in exclusively breastfed group yet (P < 0.05). Growth velocity, prevalence of obesity, wasting, underweight, and stunting did not differ between two groups.

Conclusions:

Our findings suggest that formula feeding can lead to greater weight gain and may help the catch up of length, but evidences are not convincing enough to suggest the formula as an obesogenic feeding in the studied area. To make a conclusion, we suggest comparing the privileged and unprivileged areas and controlling for confounding variables including family hygiene and infant feeding practices between formula-fed and breastfed infants.

Docosahexaenoic Acid (DHA) Induced Morphological Differentiation of Astrocytes Is Associated with Transcriptional Upregulation and Endocytosis of β2-AR

Docosahexaenoic acid (DHA), an important ω-3 fatty acid, is abundantly present in the central nervous system and is important in every step of brain development. Much of this knowledge has been based on studies of the role of DHA in the function of the neurons, and reports on its effect on the glial cells are few and far between. We have previously reported that DHA facilitates astrocyte differentiation in primary culture. We have further explored the signaling mechanism associated with this event. It was observed that a sustained activation of the extracellular signal-regulated kinase (ERK) appeared to be critical for DHA-induced differentiation of the cultured astrocytes. Prior exposure to different endocytic inhibitors blocked both ERK activation and differentiation of the astrocytes during DHA treatment suggesting that the observed induction of ERK-2 was purely endosomal. Unlike the β₁-adrenergic receptor (β₁-AR) antagonist, atenolol, pre-treatment of the cells with the β₂-adrenergic receptor (β₂-AR) antagonist, ICI-118,551 inhibited the DHA-induced differentiation process, indicating a downstream involvement of β₂-AR in the differentiation process. qRT-PCR and western blot analysis demonstrated a significant induction in the mRNA and protein expression of β₂-AR at 18-24 h of DHA treatment, suggesting that the induction of β₂-AR may be due to transcriptional upregulation. Moreover, DHA caused activation of PKA at 6 h, followed by activation of downstream cAMP response element-binding protein, a known transcription factor for β₂-AR. Altogether, the observations suggest that DHA upregulates β₂-AR in astrocytes, which undergo endocytosis and signals for sustained endosomal ERK activation to drive the differentiation process.

Low omega-6/omega-3 ratio in a maternal protein-deficient diet promotes histone-3 changes in progeny neural cells and favors leukemia inhibitory factor genetranscription

Omega-3 (n-3) fatty acids modulate epigenetic changes critical to genesis and differentiation of neural cells. Conversely, maternal protein-malnutrition can negatively modify these changes. This study investigated whether a low n-6/n-3 ratio in a maternal diet could favor histone-3 (H3) modifications, gene transcription and differentiation in the offspring neural cells even under protein-deficiency. Female rats fed a control (Ct), or 3 types of multideficient diets differing in protein levels or linoleic/alpha-linolenic fatty acid ratios (RBD, RBD-C, RBD-SO) from 30 days prior to mating and during pregnancy. Cerebral cortex tissue and cortical cultures of progeny embryonic neurons and postnatal astrocytes were analyzed. H3K9 acetylation and H3K27 or H3K4 di-methylation levels were assessed by flow cytometry and/or immunocytochemistry. In astrocyte cultures and cortical tissue, the GFAP protein levels were assessed. Glial derived neurotrophic factor (GDNF) and leukemia inhibitory factor (LIF) gene expression were evaluated in the cortical tissue. GFAP levels were similar in astrocytes of Ct, RBD and RBD-C, but 65% lower in RBD-SO group. Higher levels of H3K9Ac were found in the neurons and H3K4Me2 in the astrocytes of the RBD group. No intergroup difference in the cortical GDNF mRNA expression or the H3K27Me2 levels in astrocytes was detected. LIF mRNA levels were higher in the RDB (P=.002) or RBD-C (P=.004) groups than in the control. The findings indicate the importance of dietary n-3 availability for the brain, even under a protein-deficient condition, inducing Histone modifications and increasing LIF gene transcription, involved in neural cell differentiation and reactivity.

Glutamate homeostasis in the adult rat prefrontal cortex is altered by cortical docosahexaenoic acid accrual during adolescence: An in vivo1H MRS study

Major psychiatric disorders are associated with dysregulated glutamate homeostasis and deficits in the omega-3 fatty acid docosahexaenoic acid (DHA). This study determined the effects of dietary-induced alterations in brain DHA accrual on cortical glutamate homeostasis in the adult rat brain. Adolescent rats were fed a control diet (n = 20), a n-3 fatty acid-deficient diet (DEF, n = 20), or a fish oil-fortified diet containing preformed DHA (FO, n = 20). In adulthood ¹H MRS scans were performed with voxels in the prefrontal cortex (PFC) and thalamus. Compared with controls, erythrocyte, PFC, and thalamus DHA levels were significantly lower in DEF rats and significantly higher in FO rats. In the PFC, but not the thalamus, glutamate was significantly elevated in DEF rats compared with controls and FO rats. Glutamine did not differ between groups and the glutamine/glutamate ratio was lower in DEF rats. No differences were observed for markers of excitotoxicity (NAA, GFAP), or astrocyte glutamate transporter (GLAST, GLT-1) or glutamine synthetase expression. Across diet groups, PFC DHA levels were inversely correlated with PFC glutamate levels and positively correlated with GLAST expression. Together these findings demonstrate that rat cortical DHA accrual during adolescence impacts glutamate homeostasis in the adult PFC.

Low-dose DHA-induced astrocyte proliferation can be attenuated by insufficient expression of BLBP in vitro

Docosahexaenoic acid (DHA) is an n-3 long chain polyunsaturated fatty acid (PUFA) that is involved in a wide range of cellular processes in human cells. Brain lipid binding protein (BLBP) exhibits a high affinity for n-3 PUFAs, especially DHA, but the precise functional contributions of DHA and BLBP in astrocytes are not clear. We analyzed cell viability and the ratio of Ki67 positive cells after manipulating DHA and/or BLBP levels in cultured astrocytes, and found that low-dose DHA stimulated proliferation of astrocytes, whereas this proliferative effect could be attenuated by downregulation of BLBP. Moreover, we found that astrocyte proliferation was directly regulated by BLBP independently of DHA. Taken together, low-dose DHA-induced astrocyte proliferation was disturbed by insufficient BLBP; and besides acting as a fatty acid transporter, BLBP was also involved in the proliferation of astrocytes directly.

N-3 Polyunsaturated Fatty Acids through the Lifespan: Implication for Psychopathology

OBJECTIVE

The impact of lifetime dietary habits and their role in physical, mental, and social well-being has been the focus of considerable recent research. Omega-3 polyunsaturated fatty acids as a dietary constituent have been under the spotlight for decades. Omega-3 polyunsaturated fatty acids constitute key regulating factors of neurotransmission, neurogenesis, and neuroinflammation and are thereby fundamental for development, functioning, and aging of the CNS. Of note is the fact that these processes are altered in various psychiatric disorders, including attention deficit hyperactivity disorder, depression, and Alzheimer's disease.

DESIGN

Relevant literature was identified through a search of MEDLINE via PubMed using the following words, "n-3 PUFAs," "EPA," and "DHA" in combination with "stress," "cognition," "ADHD," "anxiety," "depression," "bipolar disorder," "schizophrenia," and "Alzheimer." The principal focus was on the role of omega-3 polyunsaturated fatty acids throughout the lifespan and their implication for psychopathologies. Recommendations for future investigation on the potential clinical value of omega-3 polyunsaturated fatty acids were examined.

RESULTS

The inconsistent and inconclusive results from randomized clinical trials limits the usage of omega-3 polyunsaturated fatty acids in clinical practice. However, a body of literature demonstrates an inverse correlation between omega-3 polyunsaturated fatty acid levels and quality of life/ psychiatric diseases. Specifically, older healthy adults showing low habitual intake of omega-3 polyunsaturated fatty acids benefit most from consuming them, showing improved age-related cognitive decline.

CONCLUSIONS

Although further studies are required, there is an exciting and growing body of research suggesting that omega-3 polyunsaturated fatty acids may have a potential clinical value in the prevention and treatment of psychopathologies.

Review of Infant Feeding: Key Features of Breast Milk and Infant Formula

Mothers' own milk is the best source of nutrition for nearly all infants. Beyond somatic growth, breast milk as a biologic fluid has a variety of other benefits, including modulation of postnatal intestinal function, immune ontogeny, and brain development. Although breastfeeding is highly recommended, breastfeeding may not always be possible, suitable or solely adequate. Infant formula is an industrially produced substitute for infant consumption. Infant formula attempts to mimic the nutritional composition of breast milk as closely as possible, and is based on cow's milk or soymilk. A number of alternatives to cow's milk-based formula also exist. In this article, we review the nutritional information of breast milk and infant formulas for better understanding of the importance of breastfeeding and the uses of infant formula from birth to 12 months of age when a substitute form of nutrition is required.

Effects of fish oil supplementation on prefrontal metabolite concentrations in adolescents with major depressive disorder: a preliminary 1H MRS study

OBJECTIVE

To use proton magnetic resonance spectroscopy ((1)H MRS) to investigate the effects of fish oil (FO) supplementation on cortical metabolite concentrations in adolescents with major depressive disorder (MDD).

METHODS

Metabolite concentrations were determined by (1)H MRS in the anterior cingulate cortex and bilateral dorsolateral prefrontal cortex (DLPFC) of adolescents with MDD before and following 10-week open-label supplementation with low (2.4 g/day, n = 7) or high (16.2 g/day, n = 7) dose FO. Depressive symptom severity scores and erythrocyte fatty acid levels were also determined.

RESULTS

Baseline erythrocyte eicosapentaenoic acid (EPA) composition was positively correlated, and arachidonic acid (AA) and the AA/EPA ratio were inversely correlated, with choline (Cho) concentrations in the right DLPFC. Docosahexaenoic acid (DHA) composition was inversely correlated with myo-inositol (mI) concentrations in the left DLPFC. Erythrocyte EPA and DHA composition increased, and AA decreased, significantly following low-dose and high-dose FO supplementation. In the intent-to-treat sample, depressive symptom severity scores decreased significantly in the high-dose group (-40%, P < 0.0001) and there was a trend in the low-dose group (-20%, P = 0.06). There were no significant baseline-endpoint changes in metabolite levels in each voxel. In the low-dose group there were changes with large effect sizes, including a decrease in mI in the left DLPFC (-12%, P = 0.18, d = 0.8) and increases in glutamate + glutamine (Glx) (+12%, P = 0.19, d = 0.8) and Cho (+15%, P = 0.08, d = 1.2) in the right DLPFC. In the high-dose group, there was a trend for increases in Cho in the right DLPFC (+10%, P = 0.09, d = 1.2).

DISCUSSION

These preliminary data suggest that increasing the LCn-3 fatty acid status of adolescent MDD patients is associated with subtle changes in Glx, mI, and Cho concentrations in the DLPFC that warrant further evaluation in a larger controlled trial.

Docosahexaenoic acid (DHA) prevents corticosterone-induced changes in astrocyte morphology and function

The many functions of astrocytes, such as glutamate recycling and morphological plasticity, enable them to stabilize synapses environment and protect neurons. Little is known about how they adapt to glucocorticoid-induced stress, and even less about the influence of dietary factors. We previously showed that omega-3 polyunsaturated fatty acids (ω3PUFA), dietary fats which alleviate stress responses, influence the way astroglia regulate glutamatergic synapses. We have explored the role of docosahexaenoic acid (DHA), the main ω3PUFA, in the astroglial responses to corticosterone, the main stress hormone in rodents to determine whether ω3PUFA help astrocytes resist stress. Cultured rat astrocytes were enriched in DHA or arachidonic acid (AA, the main ω6PUFA) and given 100 nM corticosterone for several days. Corticosterone stimulated astrocyte glutamate recycling by increasing glutamate uptake and glutamine synthetase (GS), and altered the astrocyte cytoskeleton. DHA-enriched astrocytes no longer responded to the action of corticosterone on glutamate uptake, had decreased GS, and the cytoskeletal effect of corticosterone was delayed, while AA-enriched cells were unaffected. The DHA-dependent anti-corticosterone effect was related to fewer glucocorticoid receptors, while corticosterone increased DHA incorporation into astrocyte membranes. Thus, DHA helps astrocytes resist the influence of corticosterone, so perhaps promoting a sustainable response by the stressed brain. We show that corticosterone increases the glutamate recycling capacity of rat cortical astrocytes in culture, and alters their morphology, which may be detrimental in the long term. Increasing the membrane incorporation of docosahexaenoic acid (DHA), the main omega-3 in brain, reduces the amount of glucocorticoid receptors (GR) and prevents the effects of corticosterone. This may help the astrocytes maintain a functional phenotype in chronic stress situations.

IV. The cognitive implications of obesity and nutrition in childhood

The prevalence of childhood obesity in the United States has tripled since the 1980s and is strongly linked to the early onset of several metabolic diseases. Recent studies indicate that lower cognitive function may be another complication of childhood obesity. This review considers the research to date on the role of obesity and nutrition on childhood cognition and brain health. Although a handful of studies point to a maladaptive relationship between obesity and aspects of cognitive control, remarkably little is known regarding the impact of fat mass on brain development and cognitive function. Further, missing from the literature is the role of nutrition in the obesity-cognition interaction. Nutrition may directly or indirectly influence cognitive performance via several pathways including provision of key substrates for optimal brain health, modulation of gut microbiota, and alterations in systemic energy balance. However, in the absence of malnutrition, the functional benefits of specific nutrient intake on particular cognitive domains are not well characterized. Here, we examine the literature linking childhood obesity and cognition while considering the effects of nutritional intake. Possible mechanisms for these relationships are discussed and suggestions are made for future study topics. Although childhood obesity prevalence rates in some developed countries have recently stabilized, significant disparities remain among groups based on sex and socioeconomic status. Given that the elevated prevalence of pediatric overweight and obesity may persist for the foreseeable future, it is crucial to develop a comprehensive understanding of the influence of obesity and nutrition on cognition and brain health in the pediatric population.

Effect of diet on brain metabolites and behavior in spontaneously hypertensive rats

Attention-deficit hyperactivity disorder (ADHD) is a heterogeneous psychiatric disorder affecting 5-10% of children. One of the suggested mechanisms underlying the pathophysiology of ADHD is insufficient energy supply to neurons. Here, we investigated the role of omega 3 fatty acids in altering neural energy metabolism and behavior of spontaneously hypertensive rats (SHR), which is an animal model of ADHD. To this end, we employed Proton Magnetic Resonance Spectroscopy ((1)H MRS) to evaluate changes in brain neurochemistry in the SHR following consumption of one of three experimental diets (starting PND 21): fish oil enriched (FOE), regular (RD) and animal fat enriched (AFE) diet. Behavioral tests were performed to evaluate differences in locomotor activity and risk-taking behavior (starting PND 44). Comparison of frontal lobe metabolites showed that increased amounts of omega 3 fatty acids decreased total Creatine levels (tCr), but did not change Glutamate (Glu), total N-Acetylaspartate (tNAA), Lactate (Lac), Choline (Cho) or Inositol (Ino) levels. Although behavior was not significantly affected by different diets, significant correlations were observed between brain metabolites and behavior in the open field and elevated plus maze. SHR with higher levels of brain tCr and Glu exhibited greater hyperactivity in a familiar environment. On the other hand, risk-taking exploration of the elevated plus maze's open arms correlated negatively with forebrain tNAA and Lac levels. These findings support the possible alteration in energy metabolites in ADHD, correlating with hyperactivity in the animal model. The data also suggest that omega 3 fatty acids alter brain energy and phospholipid metabolism.

Recent developments in lipid metabolism in ruminants – the role of fat in maintaining animal health and performance

Optimising farm animal performance has long been the key focus of worldwide livestock production research. Advances in the understanding of metabolism/phenotype associations have outlined the central role of the lipid metabolism of farm animals for economically relevant phenotypic traits, such as animal health (immune status, fertility/reproductive capacity, adaptability/metabolic flexibility, robustness, well being) and performance aspects (meat/milk quality and quantity) and have led to an extensive exploitation of lipid metabolism manipulation strategies (e.g. tailored nutritional regimes, alimentary/intravenous fat supplementation, rumen-protected fat feeding, hormone application). This contribution gives an overview of established concepts to tailor animals’ lipid metabolism and highlights novel strategies to expand these application-oriented approaches via improved analysis tools, omics-approaches, cell model systems and systems biology methods.

Prenatal omega 3 fatty acid supplementation to a micronutrient imbalanced diet protects brain neurotrophins in both the cortex and hippocampus in the adult rat offspring

OBJECTIVE

Our earlier studies show that maternal diets imbalanced in micronutrients like folic acid and vitamin B12 reduced brain docosahexaenoic acid (DHA) and brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the offspring at birth and postnatal d21. This study followed the offspring till 3 months to examine the hypothesis that impaired brain neurotrophins at birth and d21 due to altered maternal micronutrients can be reversed by prenatal omega 3 fatty acid but not a postnatal control diet leading to altered cognition in adult life.

MATERIALS AND METHODS

Pregnant rats were divided into control and five treatment groups at two levels of folic acid (normal and excess folate) in the presence and absence of vitamin B12 (NFBD, EFB and EFBD). Omega 3 fatty acid supplementation was given to the vitamin B12 deficient groups (NFBDO and EFBDO). Following delivery, 8 dams from each group were shifted to control and remaining continued on same diet.

RESULTS

Imbalance in maternal micronutrients up to 3months decreased DHA, BDNF and NGF in cortex and only BDNF in the hippocampus and impaired cognitive performance. Postnatal control diet normalized BDNF in the cortex but not the hippocampus and also altered cognitive performance. Prenatal omega 3 fatty acid supplementation normalized DHA, BDNF and NGF while long term supplementation was not beneficial only when micronutrients were imbalanced.

CONCLUSION

Patterns established at birth are not totally reversible by postnatal diets and give clues for planning intervention studies for improving brain functioning and cognitive abilities.

Low docosahexaenoic acid status is associated with reduced indices in cortical integrity in the anterior cingulate of healthy male children: a 1H MRS Study

Docosahexaenoic acid (DHA, 22:6n-3) is the principal omega-3 fatty acid in mammalian brain gray matter, and emerging preclinical evidence suggests that DHA has neurotrophic and neuroprotective properties. This study investigated relationships among DHA status, neurocognitive performance, and cortical metabolism measured with proton magnetic resonance spectroscopy (1H MRS) in healthy developing male children (aged 8-10 years, n = 38). Subjects were segregated into low-DHA (n = 19) and high-DHA (n = 19) status groups by a median split of erythrocyte DHA levels. Group differences in 1H MRS indices of cortical metabolism, including choline (Cho), creatine (Cr), glutamine + glutamate + γ-aminobutyric acid (Glx), myo-inositol (mI), and n-acetyl aspartate (NAA), were determined in the right and left dorsolateral prefrontal cortex (R/L-DLPFC, BA9) and bilateral anterior cingulate cortex (ACC, BA32/33). Group differences in neurocognitive performance were evaluated with the Kaufman Brief Intelligence Test and identical-pairs version of the continuous performance task (CPT-IP). Subjects in the low-DHA group consumed fish less frequently (P = 0.02), had slower reaction times on the CPT-IP (P = 0.007), and exhibited lower mI (P = 0.007), NAA (P = 0.007), Cho (P = 0.009), and Cr (P = 0.01) concentrations in the ACC compared with the high-DHA group. There were no group differences in ACC Glx or any metabolite in the L-DLPFC and R-DLPFC. These data indicate that low-DHA status is associated with reduced indices of metabolic function in the ACC and slower reaction time during sustained attention in developing male children.

The relationship of docosahexaenoic acid (DHA) with learning and behavior in healthy children: a review

Childhood is a period of brain growth and maturation. The long chain omega-3 fatty acid, docosahexaenoic acid (DHA), is a major lipid in the brain recognized as essential for normal brain function. In animals, low brain DHA results in impaired learning and behavior. In infants, DHA is important for optimal visual and cognitive development. The usual intake of DHA among toddlers and children is low and some studies show improvements in cognition and behavior as the result of supplementation with polyunsaturated fatty acids including DHA. The purpose of this review was to identify and evaluate current knowledge regarding the relationship of DHA with measures of learning and behavior in healthy school-age children. A systematic search of the literature identified 15 relevant publications for review. The search found studies which were diverse in purpose and design and without consistent conclusions regarding the treatment effect of DHA intake or biomarker status on specific cognitive tests. However, studies of brain activity reported benefits of DHA supplementation and over half of the studies reported a favorable role for DHA or long chain omega-3 fatty acids in at least one area of cognition or behavior. Studies also suggested an important role for DHA in school performance.

Chronic morphine exposure and its abstinence alters dendritic spine morphology and upregulates Shank1

Exposure to chronic drugs of abuse has been reported to produce significant changes in postsynaptic protein profile, dendritic spine morphology and synaptic transmission. In the present study we demonstrate alterations in dendritic spine morphology in the frontal cortex and nucleus accumbens of mice following chronic morphine treatment as well as during abstinence for two months. Such alterations were accompanied with significant upregulation of the postsynaptic protein Shank1 in synaptosomal enriched fractions. mRNA levels of Shank1 was also markedly increased during morphine treatment and during withdrawal. Studies of the different postsynaptic proteins at the protein and mRNA levels showed significant alterations in the morphine treated groups compared to that of saline treated controls. Taken together, these observations suggest that Shank1 may have an important role in the regulation of spine morphology induced by chronic morphine leading to addiction.

Comparison of ex vivo cultivated human limbal epithelial stem cell viability and proliferation on different substrates

Ocular surface injury causes serious vision-related problems especially when limbal stem cells are affected. Treatment lies in the transplantation of viable donor cells. Various substrates are used for the cultivation of limbal epithelial stem cells. In the present study, viability and proliferation of ex vivo cultured limbal epithelial stem cells were examined on a variety of substrates like collagen type IV, direct plastic Petri plate, intact amniotic membrane and denuded amniotic membrane. Viability and proliferation of cells were examined by colorimetric assay and [(3)H]-thymidine incorporation study. Furthermore, matrix metalloproteinase is known to be a key regulator in stem cell migration and proliferation. This enzyme activity was studied by gelatinolytic zymography. It was found from this study that although human limbal epithelial stem cells could be cultivated on different substrates such as collagen type IV, direct plastic Petri plate, intact amniotic membrane and denuded amniotic membrane, maximum growth and proliferation was observed when cultured on intact amniotic membrane. The number of patients suffering from limbal epithelial stem cell deficiency is large compared to donor tissues available for transplantation. Hence, increased cell viability and proliferation is required to serve more patients.

Role of β-adrenoceptors in glucose uptake in astrocytes using β-adrenoceptor knockout mice

BACKGROUND AND PURPOSE

β(1) -, β(2) - and β(3) -adrenoceptors determined by functional, binding and reverse transcription polymerase chain reaction (RT-PCR) studies are present in chick astrocytes and activation of β(2) - or β(3) -adrenoceptors increase glucose uptake. The aims of the present study are to identify which β-adrenoceptor subtypes are present in mouse astrocytes, the signal transduction mechanisms involved and whether β-adrenoceptor stimulation regulates glucose uptake.

EXPERIMENTAL APPROACH

Astrocytes were prepared from four mouse strains: FVB/N, DBA/1 crossed with C57BL/6J, β(3) -adrenoceptor knockout and β(1) β(2) -adrenoceptor knockout mice. RT-PCR and radioligand binding studies were used to determine β-adrenoceptor expression. Glucose uptake and cAMP were assayed to elucidate the signalling pathways involved.

KEY RESULTS

mRNAs for all three β-adrenoceptors were identified in astrocytes from wild-type mice. Radioligand binding studies identified that β(1) - and β(3) -adrenoceptors were predominant. cAMP studies showed that β(1) - and β(2) -adrenoceptors coupled to G(s) whereas β(3) -adrenoceptors coupled to both G(s) and G(i) . However, activation of any of the three β-adrenoceptors increased glucose uptake in mouse astrocytes. Interestingly, there was no functional compensation for receptor subtype loss in knockout animals.

CONCLUSIONS AND IMPLICATIONS

This study demonstrates that although β(1) -adrenoceptors are the predominant β-adrenoceptor in mouse astrocytes and are primarily responsible for cAMP production in response to β-adrenoceptor stimulation, β(3) -adrenoceptors are also present in mouse astrocytes and activation of β(2) - and β(3) -adrenoceptors increases glucose uptake in mouse astrocytes.

EPA supplementation improves teacher-rated behaviour and oppositional symptoms in children with ADHD

AIM

Measure efficacy of eicosapentaenoic acid (EPA) in children with attention deficit hyperactivity disorder (ADHD).

METHODS

Randomized controlled trial (RCT) of 0.5 g EPA or placebo (15 weeks) in 92 children (7-12 years) with ADHD. Efficacy measure was Conners' Parent/Teacher Rating Scales (CPRS/CTRS). Fatty acids were analysed in serum phospholipids and red blood cell membranes (RBC) at baseline and endpoint with gas chromatography.

RESULTS

EPA improved CTRS inattention/cognitive subscale (p = 0.04), but not Conners' total score. In oppositional children (n = 48), CTRS total score improved ≥25% in 48% of the children receiving EPA vs. 9% for placebo [effect size (ES) 0.63, p = 0.01]. In less hyperactive/impulsive children (n = 44), ≥25% improvement was seen in 36% vs. 18% (ES 0.41, n.s.), and with both these types of symptoms 8/13 with EPA vs. 1/9 for placebo improved ≥25% (p = 0.03). Children responding to treatment had lower EPA concentrations (p = 0.02), higher AA/EPA (p = 0.005) and higher AA/DHA ratios (p = 0.03) in serum at baseline. Similarly, AA/EPA (p = 0.01), AA/DHA (p = 0.038) and total omega-6/omega-3 ratios (p = 0.028) were higher in RBC, probably because of higher AA (p = 0.011).

CONCLUSION

Two ADHD subgroups (oppositional and less hyperactive/impulsive children) improved after 15-week EPA treatment. Increasing EPA and decreasing omega-6 fatty acid concentrations in phospholipids were related to clinical improvement.

Docosahexaenoic acid supplementation increases prefrontal cortex activation during sustained attention in healthy boys: a placebo-controlled, dose-ranging, functional magnetic resonance imaging study

BACKGROUND

Emerging evidence suggests that docosahexaenoic acid (DHA, 22:6n-3), the principal omega-3 (n-3) fatty acid in brain gray matter, positively regulates cortical metabolic function and cognitive development. However, the effects of DHA supplementation on functional cortical activity in human subjects are unknown.

OBJECTIVE

The objective was to determine the effects of DHA supplementation on functional cortical activity during sustained attention in human subjects.

DESIGN

Healthy boys aged 8-10 y (n = 33) were randomly assigned to receive placebo or 1 of 2 doses of DHA (400 or 1200 mg/d) for 8 wk. Relative changes in cortical activation patterns during sustained attention at baseline and endpoint were determined by functional magnetic resonance imaging.

RESULTS

At 8 wk, erythrocyte membrane DHA composition increased significantly from baseline in subjects who received low-dose (by 47%) or high-dose (by 70%) DHA but not in those who received placebo (-11%). During sustained attention, both DHA dose groups had significantly greater changes from baseline in activation of the dorsolateral prefrontal cortex than did the placebo group, and the low-dose and high-dose DHA groups had greater decreases in the occipital cortex and cerebellar cortex, respectively. Relative to low-dose DHA, high-dose DHA resulted in greater decreases in activation of bilateral cerebellum. The erythrocyte DHA composition was positively correlated with dorsolateral prefrontal cortex activation and was inversely correlated with reaction time, at baseline and endpoint.

CONCLUSION

Dietary DHA intake and associated elevations in erythrocyte DHA composition are associated with alterations in functional activity in cortical attention networks during sustained attention in healthy boys. This trial was registered at clinicaltrials.gov as NCT00662142.

Fatty acid patterns early after premature birth, simultaneously analysed in mothers' food, breast milk and serum phospholipids of mothers and infants

Background

The supply of long-chain polyunsaturated fatty acids via the placenta is interrupted in premature infants, making them exclusively dependent on breast milk, which varies in fatty acid (FA) concentrations depending on the mother's diet.

Objective

To in a longitudinal study explore the relation between FA status in mothers and infants from an unselected cohort of prematures, not requiring intensive care.

Design

Breast milk and mothers' and infants' plasma phospholipid FA concentrations from birth to 44 weeks of gestational age were analysed and compared with mothers' food intake, assessed using a 3-day diary. Fatty acids were analysed by capillary gas-liquid chromatography.

Results

The energy intake was low in 75% of mothers, and 90% had low intake of essential FAs (EFAs). Dietary linoleic acid (LA, 18:2w6), but not w3 FAs, correlated to concentrations in breast milk. Infants' plasma and breast milk correlated for arachidonic (AA, 20:4w6), eicosapentaenoic (EPA, 20:5w3) and docosahexaenoic (DHA, 22:6w3) acids. A high concentration of mead acid (20:3w9) in the infants at birth correlated negatively to the concentrations of LA, AA and w3 FAs. Infants of mothers who stopped breastfeeding during the study period showed decreased DHA concentrations and increased w6/w3 ratios, with the opposite FA pattern seen in the mothers' plasma.

Conclusion

Although dietary w3 FAs were insufficient in an unselected cohort of mothers of premature infants, breastfeeding resulted in increased levels of DHA in the premature infants at the expense of the mothers, suggesting a general need to increase dietary w3 FAs during pregnancy and lactation.

Perinatal n-3 fatty acid deficiency selectively reduces myo-inositol levels in the adult rat PFC: an in vivo (1)H-MRS study

To investigate the effects of omega-3 fatty acid deficiency on phosphatidylinositol signaling in brain, myo-inositol (mI) concentrations were determined in the prefrontal cortex (PFC) of omega-3 fatty acid deficient rats by in vivo proton magnetic resonance spectroscopy ((1)H-MRS). To generate graded deficits in PFC docosahexaenoic acid (22:6n-3) (DHA) composition, perinatal and postweaning alpha-linolenic acid (18:3n-3) (ALA) deficiency models were used. Adult male rats were scanned in a 7T Bruker Biospec system and a (1)H-MRS spectrum acquired from the bilateral medial PFC. Rats were then challenged with SKF83959, a selective agonist at phosphoinositide (PI)-coupled dopamine D(1) receptors. Postmortem PFC fatty acid composition was determined by gas chromatography. Relative to controls, PFC DHA composition was significantly reduced in adult postweaning (-27%) and perinatal (-65%) ALA-deficiency groups. Basal PFC mI concentrations were significantly reduced in the perinatal deficiency group (-21%, P = 0.001), but not in the postweaning deficiency group (-1%, P = 0.86). Among all rats, DHA composition was positively correlated with mI concentrations and the mI/creatine (Cr) ratio. SKF83959 challenge significantly increased mI concentrations only in the perinatal deficiency group (+16%, P = 0.02). These data demonstrate that perinatal deficits in cortical DHA accrual significantly and selectively reduce mI concentrations and augment receptor-generated mI synthesis.

Comparison of biochemical effects of statins and fish oil in brain: the battle of the titans

Neural membranes are composed of glycerophospholipids, sphingolipids, cholesterol and proteins. The distribution of these lipids within the neural membrane is not random but organized. Neural membranes contain lipid rafts or microdomains that are enriched in sphingolipids and cholesterol. These rafts act as platforms for the generation of glycerophospholipid-, sphingolipid-, and cholesterol-derived second messengers, lipid mediators that are necessary for normal cellular function. Glycerophospholipid-derived lipid mediators include eicosanoids, docosanoids, lipoxins, and platelet-activating factor. Sphingolipid-derived lipid mediators include ceramides, ceramide 1-phosphates, and sphingosine 1-phosphate. Cholesterol-derived lipid mediators include 24-hydroxycholesterol, 25-hydroxycholesterol, and 7-ketocholesterol. Abnormal signal transduction processes and enhanced production of lipid mediators cause oxidative stress and inflammation. These processes are closely associated with the pathogenesis of acute neural trauma (stroke, spinal cord injury, and head injury) and neurodegenerative diseases such as Alzheimer disease. Statins, the HMG-CoA reductase inhibitors, are effective lipid lowering agents that significantly reduce risk for cardiovascular and cerebrovascular diseases. Beneficial effects of statins in neurological diseases are due to their anti-excitotoxic, antioxidant, and anti-inflammatory properties. Fish oil omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, have similar anti-excitotoxic, antioxidant and anti-inflammatory effects in brain tissue. Thus the lipid mediators, resolvins, protectins, and neuroprotectins, derived from eicosapentaenoic acid and docosahexaenoic acid retard neuroinflammation, oxidative stress, and apoptotic cell death in brain tissue. Like statins, ingredients of fish oil inhibit generation of beta-amyloid and provide protection from oxidative stress and inflammatory processes. Collective evidence suggests that antioxidant, anti-inflammatory, and anti-apoptotic properties of statins and fish oil contribute to the clinical efficacy of treating neurological disorders with statins and fish oil. We speculate that there is an overlap between neurochemical events associated with neural cell injury in stroke and neurodegenerative diseases. This commentary compares the neurochemical effects of statins with those of fish oil.

Increased beta(2)-adrenergic receptor activity by thyroid hormone possibly leads to differentiation and maturation of astrocytes in culture

(1) Our earlier studies indicate a downsteam regulatory role of the beta-adrenergic receptor (beta-AR) system in thyroid hormone induced differentiation and maturation of astrocytes. In the present study we have investigated the contributions of the subtypes of beta-AR in the above phenomenon. (2) Primary astrocyte cultures were grown under thyroid hormone deficient as well as under euthyroid conditions. [(125)I]Pindolol ([(125)I]PIN) binding studies showed a gradual increase in the specific binding to beta(2)-AR when observed at 5, 10, 15, and 20 days under both cultural conditions. Thyroid hormone caused an increase in binding of [(125)I]PIN to beta(2)-AR compared to thyroid hormone deficient controls at all ages of astrocyte culture. (3) Saturation studies using [(125)I]PIN in astrocyte membranes prepared from 20-day-old cultures showed a significant increase in the affinity of the receptors (K (D)) in the thyroid hormone treated cells without any change in receptor number (B (max)). (4) beta(2)-AR mRNA levels were measured by real-time PCR during ontogenic development as well as during exposure of 10-day-old hypothyroid cultures to normal levels of thyroid hormone for 2, 6, 12, and 24 h. None of the conditions caused any significant change in the beta(2)-adrenergic receptor mRNA levels when compared with corresponding hypothyroid controls. (5) Over expression of beta(2)-AR cDNA in hypothyroid astrocytes caused morphological transformation in spite of the absence of thyroid hormone in the medium. (6) Taken together, results suggest thyroid hormone causes a selective increase in [(125)I]PIN binding to beta(2)-AR due to increase in receptor affinity, which may lead to maturation of astrocytes.

Effect of fatty acids isolated from edible oils like mustard, linseed or coconut on astrocytes maturation

The omega-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA, 22:6n-3) has been previously shown to facilitate some of the vital functions of astrocytes. Since some dietary oils contain alpha-linolenic acid (ALA, 18:3n-3), which is a precursor of DHA, we examined their effect on astrocyte development. Fatty acids (FAs) were isolated from commonly used oils and their compositions were determined by GLC. FAs from three oils, viz. coconut, mustard and linseed were studied for their effect on astrocyte morphology. Parallel studies were conducted with FAs from the same oils after heating for 72 h. Unlike coconut oil, FAs from mustard and linseed, both heated and raw, caused significant morphogenesis of astrocytes in culture. ss-AR binding was also substantially increased in astrocytes treated with FAs from raw mustard and linseed oils as compared to astrocytes grown in normal medium. The expression profile of the isoforms of GFAP showed that astrocyte maturation by FAs of mustard and linseed oil was associated with appearance of acidic variants of GFAP and disappearance of some neutral isoforms similar to that observed in cultures grown in serum containing medium or in the presence of DHA. Taken together, the study highlights the contribution of specific dietary oils in facilitating astrocyte development that can have potential impact on human health.

Elevated oxidation of docosahexaenoic acid, 22:6 (n−3), in brain regions of rats undergoing ethanol withdrawal

Ethanol withdrawal is a serious clinical problem owing in part to over stimulation of ionotropic glutamate receptors in the brain and is linked to elevated oxidative damage. In this study, we tested the hypothesis that lipid peroxidation is elevated in the brain tissue of rats fed an ethanol-containing diet for 6 weeks followed by 24h of withdrawal. We measured F(2)-isoprostanes (IsoPs), as products of arachidonic acid (20:4, n-6) oxidation and F(4)-neuroprostanes (NeuroPs), as products of docosahexaenoic acid (22:6, n-3; DHA) oxidation. Levels of NeuroPs were significantly elevated in the cerebral cortex (97%) and brainstem (68%) of animals undergoing ethanol withdraw versus control. In contrast, elevations in IsoP content (39%) occurred only in the cerebellum of animals in withdrawal versus control animals. These data demonstrate that DHA, versus arachidonic acid, is particularly vulnerable to oxidative damage in ethanol withdrawal.