Central administration of dipeptides, beta-alanyl-BCAAs, induces hyperactivity in chicks

<p>Abstract</p> <p>Background</p> <p>Carnosine (β-alanyl-L-histidine) is a putative neurotransmitter and has a possible role in neuron-glia cell interactions. Previously, we reported that carnosine induced hyperactivity in chicks when intracerebroventricularly (i.c.v.) administered. In the present study, we focused on other β-alanyl dipeptides to determine if they have novel functions.</p> <p>Results</p> <p>In Experiment 1, i.c.v. injection of β-alanyl-L-leucine, but not β-alanyl-glycine, induced hyperactivity behavior as observed with carnosine. Both carnosine and β-alanyl-L-leucine stimulated corticosterone release. Thus, dipeptides of β-alanyl-branched chain amino acids were compared in Experiment 2. The i.c.v. injection of β-alanyl-L-isoleucine caused a similar response as β-alanyl-L-leucine, but β-alanyl-L-valine was somewhat less effective than the other two dipeptides. β-Alanyl-L-leucine strongly stimulated, and the other two dipeptides tended to stimulate, corticosterone release.</p> <p>Conclusion</p> <p>These results suggest that central β-alanyl-branched chain amino acid stimulates activity in chicks through the hypothalamus-pituitary-adrenal axis. We named β-alanyl-L-leucine, β-alanyl-L-isoleucine and β-alanyl-L-valine as Excitin-1, Excitin-2 and Excitin-3, respectively.</p

Central administration of L- and D-aspartate attenuates stress behaviors by social isolation and CRF in neonatal chicks

Intracerebroventricular (i.c.v.) administration of L-aspartate (L-Asp) attenuates stress responses in neonatal chicks, but the mechanism has not been clarified. In the present study, three behavioral experiments were carried out under socially isolated stressful conditions exacerbated by the use of corticotrophin-releasing factor (CRF). In Experiment 1, i.c.v. injection of L-Asp attenuated behavioral stress responses (distress vocalization and active wakefulness) in a dose-dependent manner. Furthermore, L-Asp increased time spent standing/sitting motionless with eyes open and sitting motionless with head dropped (sleeping posture) in comparison with the group receiving CRF alone. In Experiment 2, i.c.v. injection of D-Asp dosedependently decreased the number of distress vocalizations and the amount of time spent in active wakefulness. D-Asp increased the time spent standing/sitting motionless with eyes open compared with the group receiving CRF alone. In Experiment 3, we directly compared the effect of L-Asp with that of D-Asp. Both L- and D-Asp induced sedative effects under an acutely stressful condition. However, L-Asp, but not D-Asp, increased the time spent in a sleeping posture. These results indicate that both L- and D-Asp, when present in the brain, could induce a sedative effect, while the mechanism for hypnosis in neonatal chicks may be different for L-Asp in comparison with D-Asp

Analysis of Infant Microbiota Composition and the Relationship With Breast Milk Components in the Asian Elephant (Elephas Maximus) at the Zoo

The prevention of diseases through health control is essential at zoos. Here, we investigated the gut microbiota formation during infancy in an Asian elephant and compared the composition between infant and mother. Besides, we analyzed the components of breast milk and examined the correlation with the infant gut microbiota. Analysis revealed the gut microbiota of the infant contained high amount of Lactobacillales and its diversity was relatively low compared to that of the mother. We found several milk components, showed a positive correlation with the change of Lactobacillales. The present study revealed the mechanism of gut microbiota formation during infancy in an Asian elephant and provides important insights into the health control of Asian elephants in zoos

Oxidative damage and brain concentrations of free amino acid in chicks exposed to high ambient temperature

High ambient temperatures (HT) reduce food intake and body weight in young chickens, and HT can cause increased expression of hypothalamic neuropeptides. The mechanisms by which HT act, and the effects of HT on cellular homeostasis in the brain, are however not well understood. In the current study lipid peroxidation and amino acid metabolism were measured in the brains of 14 d old chicks exposed to HT (35 °C for 24- or 48-h) or to control thermoneutral temperature (CT; 30 °C). Malondialdehyde (MDA) was measured in the brain to determine the degree of oxidative damage. HT increased body temperature and reduced food intake and body weight gain. HT also increased diencephalic oxidative damage after 48 h, and altered some free amino acid concentrations in the diencephalon. Diencephalic MDA concentrations were increased by HT and time, with the effect of HT more prominent with increasing time. HT altered cystathionine, serine, tyrosine and isoleucine concentrations. Cystathionine was lower in HT birds compared with CT birds at 24 h, whilst serine, tyrosine and isoleucine were higher at 48 h in HT birds. An increase in oxidative damage and alterations in amino acid concentrations in the diencephalon may contribute to the physiological, behavioral and thermoregulatory responses of heat-exposed chicks

Decreased Exploratory Activity in a Mouse Model of 15q Duplication Syndrome; Implications for Disturbance of Serotonin Signaling

Autism spectrum disorders (ASDs) have garnered significant attention as an important grouping of developmental brain disorders. Recent genomic studies have revealed that inherited or de novo copy number variations (CNVs) are significantly involved in the pathophysiology of ASDs. In a previous report from our laboratory, we generated mice with CNVs as a model of ASDs, with a duplicated mouse chromosome 7C that is orthologous to human chromosome 15q11-13. Behavioral analyses revealed paternally duplicated (patDp/+) mice displayed abnormal behaviors resembling the symptoms of ASDs. In the present study, we extended these findings by performing various behavioral tests with C57BL/6J patDp/+ mice, and comprehensively measuring brain monoamine levels with ex vivo high performance liquid chromatography. Compared with wild-type controls, patDp/+ mice exhibited decreased locomotor and exploratory activities in the open field test, Y-maze test, and fear-conditioning test. Furthermore, their decreased activity levels overcame increased appetite induced by 24 hours of food deprivation in the novelty suppressed feeding test. Serotonin levels in several brain regions of adult patDp/+ mice were lower than those of wild-type control, with no concurrent changes in brain levels of dopamine or norepinephrine. Moreover, analysis of monoamines in postnatal developmental stages demonstrated reduced brain levels of serotonin in young patDp/+ mice. These findings suggest that a disrupted brain serotonergic system, especially during postnatal development, may generate the phenotypes of patDp/+ mice

Feeding the outer bran fraction of rice alters hepatic carbohydrate metabolism in rats

Dietary intake of fiber-rich food has been reported to contribute to multiple health benefits. The aim of the current study is to investigate the effects of a diet containing the outer bran fraction of rice (OBFR), which is rich in insoluble fiber, on the intestinal environment and metabolite profiles of rats. Fourteen 8-week-old male Sprague–Dawley rats were divided into a control group and an OBFR group. For a period of 21 days, the control group was fed a control diet, while the OBFR group was fed a diet containing 5% OBFR. Metabolomics analysis revealed drastic changes in the cecal metabolites of the rats fed the OBFR diet. Furthermore, in the plasma and liver tissue, the concentrations of metabolites involved in pyruvate metabolism, the pentose phosphate pathway, gluconeogenesis, or valine, leucine, isoleucine degradation were changed. Concordantly, the OBFR diet increased the expression of genes encoding enzymes involved in these metabolic pathways in the livers of the rats. Collectively, these results suggest that the OBFR diet altered the concentrations of metabolites in the cecal contents, plasma, and liver, and the hepatic gene expressions of rats, and that this may have mainly contributed to carbohydrate metabolism in the liver

Oral Administration of D-aspartate, but not of L-aspartate, Reduces Food Intake in Chicks

In the present study, we determined the effects of oral administration of L- and D-aspartate (L-Asp and D-Asp) on food intake over a period of2haftertheadministration, as well as its effects on the concentration of L- and D-Asp in the brain and plasma. Chicks were orally administered different levels (0, 3.75, 7.5 and 15 mmol/kg body weight) of L-Asp (Experiment 1) and D-Asp (Experiment 2). Administration of several doses of L-Asp linearly increased the concentration of L-Asp, but not of D-Asp, in plasma. Oral L-Asp somewhat modified the levels of L- and D-Asp levels in the telencephalon, but not in the diencephalon. However, food intake was not significantly changed with doses of L-Asp. On the other hand, D-Asp strongly and dose-dependently inhibited food intake over a period of 2 h after the administration. Oral D-Asp clearly increased D-Asp levels in the plasma and diencephalon, but no significant changes in L-Asp were detected. Brain monoamine contents were only minimally influenced by L- or DAsp administration. We conclude that D-Asp may act as an anorexigenic factor in the diencephalon. Key words: brain, D-Aspartate, food intake, L-Aspartate, neonatal chick, plasm