Brain Dopamine Levels Research Articles

In-silico and in-vivo evaluation of comparative enhanced neurogenic performance by energy drinks

Objective: In the present society, the energy drinks (EDs) are used by general public and mainly by the sports persons. Though the caffeine content of EDs is creating health consequences on excess consumption, the present study targets their health benefits on central nervous system (CNS) focusing antidepressant and cognitive potentiality. The most typically used EDs have been selected for the study such as Red Bull, Monster and Enerzal for the present research. Methodology: The study started with in-silico studies to get information about the neurological receptor binding of the major and common chemical components of the EDs. The antidepressant study of energy drinks was carried out following FST (Forced Swim Test) and TST (Tail suspension test) methods. Their cognition effect was assessed by using Y-maze apparatus. Further, their mechanism of action was evaluated by estimating their effect on brain dopamine and serotonin level. Results: In-silico study revealed the enhanced agonistic binding of the major common components of the EDs to D2 and serotonin receptors. Further their significant (p<0.001) antidepressant property was estimated both in tail suspension and forced swim tests along with significant cognitive property.

Insights into the role of dopamine in olfactory learning behavior of honeybee

One of the brain's primary functions is remembering and learning the information related to food and odour. Since biogenic amines discovery in invertebrate and vertebrate, dopamine is considered a key modulator and neurotransmitter involved in honeybees' olfactory learning. Dopamine (DA) has a major part to play in rewarding prediction, learning, invigorating social behavior, and motivation. Here we examined the effect of dopamine in the olfactory learning behavior of honeybees. We used the same age (14-days old) honeybees, Apis mellifera and Apis cerana to evaluate the proboscis extension response and characterized brain dopamine's effect on olfactory learning behavior. Both species were individually trained by performing three learning trials with sucrose solution and odor 1-Hexanol. High-performance liquid chromatography (HPLC) determined the brain dopamine level using electrochemical detection. Our findings showed that Apis mellifera learned better and higher brain dopamine levels than Apis cerana. Thus, we show that dopamine acts as an important neurotransmitter and modulator of motivation and influences honeybee cognition.

Possible Influence of Loxoprofen in Lipopolysaccharide Induced Alterations in Brain Serotonin, Noradrenaline and Dopamine Levels in Chronic Mild Stress Treated Mice

The objective of the present study was to evaluate the influence of Loxoprofen on serotonin, noradrenaline and dopamine levels in absence or presence of Lipopolysaccharide (LPS) after chronic mild stress treatment in mice brain. Background: It has been reported that there is an abnormal prostaglandin levels in depression. Several studies indicated that there has been an elevated level of prostaglandins in depression. It has been reported that Loxoprofen remarkably decrease the PGE2 level in regions of brain. Method: There was an estimation of serotonin, noradrenaline and dopamine levels in mice brain after 21 days of chronic mild stress schedule in which mice were subjected to treatment of Loxoprofen (16.8mg/kg, p.o.) or Venlafexine (4mg/kg, i.p.) with or without treatment of LPS (0.5mg/kg, i.p.) for last 14 days. Results: There was a significant decrease in brain serotonin, noradrenaline and dopamine levels in stressed mice as compared to normal mice. There was a significant decrease in brain serotonin, noradrenaline and dopamine levels in LPS treated stressed mice as compared to LPS treated normal mice. The treatment of Loxoprofen in LPS treated stressed mice showed a significant increase in brain serotonin and noradrenaline levels but not dopamine levels as compared to LPS treated stressed mice. The treatment of Venlafexine in LPS treated stressed mice showed a significant increase in all above mentioned three brain neurotransmitters levels as compared to LPS treated stressed mice.Conclusion: The results of the present study showed that Loxoprofen influence the LPS induced alterations in serotonin and noradrenaline levels in mice brain after 21 day exposure of chronic mild stress schedule. It can indicate the possible antidepressant-like effect of Loxoprofen in mice subjected to chronic mild stress schedule, having its possible implication in future treatment of depression.

NURR1-deficient mice have age- and sex-specific behavioral phenotypes.

The transcription factor NURR1 is essential to the generation and maintenance of midbrain dopaminergic (mDA) neurons and its deregulation is involved in the development of dopamine (DA)‐associated brain disorders, such as Parkinson's disease (PD). The old male NURR1 heterozygous knockout (NURR1‐KO) mouse has been proposed as a model of PD due to its altered motor performance that was, however, not confirmed in a subsequent study. Based on these controversial results, we explored the effects of the NURR1 deficiency on locomotor activity, motor coordination, brain and plasma DA levels, blood pressure and heart rate of old mice, also focusing on the potential effect of sex. As a probable consequence of the role of NURR1 in DA pathway, we observed that the old NURR1‐KO mouse is characterized by motor impairment, and increased brain DA level and heart rate, independently from sex. However, we also observed an alteration in spontaneous locomotor activity that only affects males. In conclusion, NURR1 deficiency triggers sex‐ and age‐specific alterations of behavioral responses, of DA levels and cardiovascular abnormalities. Further studies in simplified systems will be necessary to dissect the mechanism underlying these observations.

Antidepressant-like Activity of Patchouli Oil var. Tapak Tuan (Pogostemon cablin Benth) via Elevated Dopamine Level: A Study Using Rat Model.

Essential oils are gaining popularity for their use in treating depression, including that extracted from patchouli leaves and stems (Pogostemon cablin). Herein, we used patchouli oil (PO) containing a high amount of patchouli alcohol derived from P. cablin var. Tapak Tuan. The aim of this study was to investigate the antidepressant potential of PO, with a variety of patchouli alcohol concentrations obtained from a separation process using vacuum distillation with different temperature ranges. The initial patchouli oil (iPO) was traditionally distilled by a local farmer and further distilled using a rotary evaporator at temperature ranges of 115–160 °C (POF-1); 120–160 °C (POF-2), and 125–160 °C (POF-3), resulting in products with different patchouli alcohol concentrations. POF-3, with the highest patchouli alcohol content of 60.66% (based on gas chromatography-mass spectrometry), was used for cooling crystallization, resulting in 100% patchouli alcohol crystal (pPA). A tail suspension test (TST) was performed on a rat model to screen the antidepressant potential of iPO and its derivatives. The TST results revealed that POF-3 had the best antidepressant-like effect and was second only to the fluoxetine-based antidepressant, Kalxetin®, where both groups had significant reductions of immobility time post-treatment (p < 0.0001). Other than patchouli alcohol, POF-3 also contained ledol and trans-geraniol, which have been reported for their antidepressant-related activities. Brain dopamine levels increased significantly in the group treated with POF-3 (p < 0.05 as compared with the control group), suggesting its primary anti-depressant mechanism. These findings suggest the potential of vacuum-distilled patchouli oil in reducing depression via dopamine elevation.

Responses to artificial selection for locomotor activity: A focus on death feigning in red flour beetle.

Whole-organism performance, including locomotor activity, is an important fitness trait in many animals. Locomotor activity is often classified into sprint speed and locomotor endurance and differences in sprint speed and locomotor endurance affect on other traits such as life-history traits. Previous studies found that locomotor endurance, sprint speed and brain dopamine (DA) levels are correlated with artificial selection for death feigning (an anti-predator behaviour that we refer to as 'death-feigning syndrome') in some insect species. Thus, if the syndrome has a genetic basis, death feigning, sprint speed and brain DA levels may be affected by artificial selection for locomotor endurance. We artificially selected for locomotor endurance over 10generations in the red flour beetle Tribolium castaneum, and established higher (H) and lower activity (L) strains, then compared their death-feigning behaviour, sprint speed and brain DA levels. H-strain beetles exhibited significantly shorter duration of death-feigning, and significantly higher sprint speeds, suggesting variation in death-feigning syndrome. Surprisingly, although brain DA expression affects various animal behaviours, we found no significant differences in the brain DA expressions of H- and L-strain beetles. Thus, our results imply genetic correlations between locomotor endurance, sprint speed and death feigning, but not with brain DA expression, suggesting that differences in the biogenic amine results of our and previous studies may reflect differences in behavioural expression mechanisms.

Emerging Microbiome Genetic Engineering Technology for Stable Levodopa Delivery in Parkinson’s Disease

Dopamine replacement in the form of a levodopa/carbidopa tablet has been the gold‐standard therapy for Parkinson’s disease (PD) for over six decades. Oral tablet dosing of L‐DOPA 3‐4 times/day is quite efficacious in controlling early‐stage PD symptoms). However, beyond its ~5‐yr clinical honeymoon period, this treatment becomes increasingly associated with L‐DOPA‐induced dyskinesia (LID) and ‘ON‐OFF’ motor complications resulting from the non‐continuous, pulsatile delivery of L‐DOPA to the brain. Addressing this challenge, we devised an innovative strategy to supplement the host’s microbiota with the human probiotic E.coliNissle 1917 (EcN) genetically engineered to continuously produce L‐DOPA (EcNLDOPA) with no significant side effects. By harnessing emerging synthetic biology and genetic engineering technologies, we successfully established four generations of EcNLDOPA(1‐4) and characterized their ability to endogenously synthesize L‐DOPA from tyrosine using the recombinant hpaB/C gene. The initially designed plasmid‐based EcNLDOPA1,2 systems were further improved by developing the chromosome‐integrated and regulatable systems EcN3‐4L‐DOPA using advanced Sce‐ROPE genetic engineering. The steady‐state levels of plasma and brain L‐DOPA, dopamine and its metabolites, as well as gut colonization of EcNLDOPA, were assessed over time. Our results show that all EcNLDOPAstrains effectively generate L‐DOPA in a dose‐ and time‐dependent manner in vitro, indicating that the biotherapeutic dosage can be personalized to each patient’s needs. Our mouse pharmacokinetic studies revealed that steady‐state levels of plasma L‐DOPA and brain dopamine can be achieved by oral administration of EcNLDOPA. Importantly, our pharmacodynamic efficacy studies of the L‐DOPA response in the progressive neurodegenerative MitoPark mouse model of PD showed improved performance in motor, cognitive and mood‐related tasks. Colonization studies show that our EcNLDOPA biotherapeutic requires only once or twice daily dosing. Our novel re‐engineered, self‐replicating EcNLDOPA microbial bio‐therapeutics offers an entirely new L‐DOPA treatment paradigm capable of ensuring long‐term efficacy while minimizing side‐effects

Combined Treatment of Levetiracetam and Mesenchymal Stem Cells Reverses the Biochemical Aberrations in the Acute Phase of Epilepsy Induced by Pilocarpine in Rats

In spite of the enormous evolution of the novel anti-seizure medications, about one-third of epilepsy patients stay resistant to the existing therapeutic drugs. Stem cells have provoked hopeful for treating diverse neurologic diseases comprises epilepsy. The rational of this investigation was to appraise the therapeutic intervention of a combination of levetiracetam (LEV) with rodent adipose-derived mesenchymal stem cells (ADMSCs) or rodent bone marrow-derived mesenchymal stem cells (BMMSCs) in counteracting pilocarpine-induced acute epilepsy in rats. In this research, the isolation and preparation of ADMSCs and BMMSCs from male albino rats were carried out. The identification of ADMSCs and BMMSCs was performed morphologically in the culture by using the inverted microscope and by the detection of the cell surface profile by using the flow cytometry technique. The induction of acute epilepsy was achieved by intraperitoneal injection of a single dose of pilocarpine (380 mg/kg b.wt). This study was conducted on fifty six adult male albino rats which were assigned into seven equal groups (8 rats/group); Group (1): Control, Group (2): Epileptic, Group (3): Epileptic + LEV (300 mg/kg b.wt daily for 12 weeks by gastric intubation with an oral gavage), Group (4): Epileptic + ADMSCs (single dose of ADMSCs; 3 × 106 cells/rat; intravenously), Group (5): Epileptic + BMMSCs (single dose of BMMSCs 3 × 106 cells/rat; intravenously), Group (6) : Epileptic + ADMSCs + LEV and Group (7) Epileptic + BMMSCs + LEV. After the end of the experimental period (12 weeks), all rats were tested by the mean electric shock (MES) test to prove the presence of strong seizures in the epileptic group and the modulation of these seizures after treatments. Then, the rats were decapitated and the whole brain of each rat was dissected into two halves, the first half was used for the quantitative determination of GABA, glutamate, dopamine, bFGF, BDNF, IL-6 and TNF-α, while the second half was fixed in formalin saline for histological investigation. The findings of the present work demonstrated that the morphological appearance of the isolated MSCs manifests spindle-shape. The flow cytometric analysis showed that the isolated MSCs are positive for CD90 and negative for CD14 and CD45. The homing of MSCs in the brain tissue of the treated rats was verified by their staining with the fluorescent dye. The recordings of the MES indicated the presence of strong seizures in the epileptic rats which were ameliorated after treatment with LEV, ADMSCs, BMMSCs. The level of brain GABA decreased significantly in the epileptic rats, whereas the level of brain glutamate, dopamine, bFGF, BDNF, IL-6 and TNF-α increased significantly; these alterations were improved after treatment with LEV or ADMSCs or BMMSCs. The histological examination of the brain tissue of the epileptic rats showed great histopathological alterations which were amended by the different treatment options. The combined treatment of either ADMSCs or BMMSCs with LEV displayed superior advantageous effect versus the single use of each type of cell in combating the acute phase of epilepsy. In conclusion, the outcomes of the present approach disclosed that the combined treatment of either ADMSCs or BMMSCs with the antiepileptic drug LEV has synergistic effect in alleviation of the behavioral and biochemical aberrations as well as brain histological deformation during the acute phase of epilepsy.

Cohabitation With Atlantic Salmon (Salmo salar) Affects Brain Neuromodulators But Not Welfare Indicators in Lumpfish (Cyclopterus lumpus).

Lumpfish are utilized to combat ectoparasitic epidemics in salmon farming. Research gaps on both cleaning behavior and client preferences in a natural environment, emphasizes the need to investigate the physiological impacts on lumpfish during cohabitation with piscivorous Atlantic salmon. Lumpfish (39.9 g, S.D ± 8.98) were arranged in duplicate tanks (n = 40 per treatment) and exposed to Live Atlantic salmon (245.7 g, S.D ± 25.05), salmon Olfaction or lifelike salmon Models for 6 weeks. Growth and health scores were measured every second week. In addition, the final sampling included measurements of neuromodulators, body color, and plasma cortisol. A stimulation and suppression test of the hypothalamic-pituitary-interrenal (HPI) axis was used for chronic stress assessment. Results showed that growth, health scores, and body color remained unaffected by treatments. Significant reductions in levels of brain dopamine and norepinephrine were observed in Live compared to Control. Plasma cortisol was low in all treatments, while the stimulation and suppression test of the HPI axis revealed no indications of chronic stress. This study presents novel findings on the impact on neuromodulators from Atlantic salmon interaction in the lumpfish brain. We argue that the downregulation of dopamine and norepinephrine indicate plastic adjustments to cohabitation with no negative effect on the species. This is in accordance with no observed deviations in welfare measurements, including growth, health scores, body color, and stress. We conclude that exposure to salmon or salmon cues did not impact the welfare of the species in our laboratory setup, and that neuromodulators are affected by heterospecific interaction.

Anxiolytic and antidepressant-like activities of aqueous extract of Azadirachta indica A. Juss. flower in the stressed rats

The aim of this study was to evaluate whether an aqueous extract of Azadirachta indica A. Juss. (A. indica) flower had anxiolytic and antidepressant-like effects in the stressed rats. Male Wistar rats were randomly allocated to one of two experimental groups: control or stress. The stress groups were received restraint stress for 3 h. The stressed rats were administered a vehicle, diazepam, fluoxetine, and A. indica at doses of 250, 500, and 1000 mg/kg BW for 30 days. The elevated plus-maze test (EPMT), the forced swimming test (FST), and the open field test (OFT) were used to assess anxiolytic and antidepressant-like behaviors. In the EPMT, the percentage of the number of open arm entries and the duration spent in open arms were measured. These measurements were considerably enhanced in the stressed rats treated with diazepam and A. indica flower extract at a dose of 500 mg/kg BW. Furthermore, the stressed rats given fluoxetine and A. indica flower extract at all doses employed in this study showed a significant reduction in the amount of time the rats were immobilized in the FST. However, there was no significant difference in spontaneous locomotor activity between any of the groups. Additionally, the stressed rats treated with either positive control medications or A. indica flower extract exhibited significantly higher brain dopamine (DA) and serotonin (5-HT) levels, but lower blood cortisol levels as compared to the stressed rats treated with vehicle. Moreover, A. indica flower extract had no harmful effect on the stressed rats’ liver tissue.

Experimental validation of Vitex negundo leaves hydroalcoholic extract for neuroprotection in haloperidol induced parkinson's disease in rat.

Parkinsonism is a neurodegenerative disease, mainly imbalance in dopamine and acetylcholine neurotransimitter in mid brain, which manifestation of dysfunctions of extrapyramidal like akinesia, tremor, rigidity and catalepsy etc., even cognitive and memory loss. The current study is framed to evaluate the effect of Vitex negundo (VNL) leaf extract in Haloperidol induced PD in rats. In vitro studies of antioxidant capacity were checked via DPPH and NO assays and identified its Acetylcholinesterase (AChE) inhibitory activity. Secondly the In vivo study of anti-PD activity in Haloperidol induced in rats were evaluated by Rotarod, morris water maze (MWM), cooks pole climb (CPC), actophotometer, novel object recognition (NOR), and T-maze were utilized to assess extrapyramidal, cognitive and memory function. Thirdly, changes in biomarker level viz. (AChE), butyrylcholinesterase. (BChE) in hippocampus and cortex, reduced glutathione (GSH), malondialdehyde (MDA), total protein (TP), superoxide dismutase (SOD), catalase (CAT), and dopamine level in the whole brain were measured. Finally, histopathology of hippocampus and cortex was examined at 40x magnification to access restoring integrity and maintaining the architecture of neuronal cell in the treatment group compared to control group and L-DOPA as a standard treatment group. V. negundo showed potent antioxidant potency on scavenging of DPPH (IC50 84.81μg/ml) and NO (IC50 133.20μg/ml) and possess AChE inhibitory potency (IC50 114.35μg/ml) by in vitro studies. The Rotarod, MWM, CPC, Actophotometer, NOR, T-maze demonstrated that Haloperidol group administration declines performance time, ELT, TL and decreases locomotion, cognitive and memory respectively. The treatment of VNL 100, 200, and 400mg/kg p.o. significantly (p < 0.05 to p < 0.0001) reversed. Whole brain AChE, BChE, and MDA level were significantly raised and GSH, TP, SOD, CAT and Dopamine were significantly declined in Haloperidol treated group rats, especially V. negundo 400mg/kg p.o. highly significantly ameliorate the Haloperidol group altered pathological changes through the restoration of the cholinergic function, enhancing the antioxidant defense and by increasing the dopaminergic function. The current study provides validation of V. negundo for its anti-PD activity and could be a valuable source for the treatment of PD in future.

Synthesis and biological evaluation of paeoveitol D derivatives as new melatonin receptor agonists with antidepressant activities.

Our previous study demonstrated that paeoveitol D, a benzofuran compound isolated from Paeonia veitchii, displayed activity on MT1 and MT2 receptors with agonistic ratios of 57.5% and 51.6% at a concentration of 1 mM. To explore the structure-activity relationships, 34 paeoveitol D derivatives were synthesized and evaluated for their MT1 and MT2 agonistic activities using the Fluo-8 calcium assay. Among them, 16 and 18 derivatives increased agonistic activities on the MT1 and MT2 receptors, respectively. Compound 18 indicated EC50 values of 21.0 and 298.9 μM on MT1 and MT2 receptors in agonistic dose response curves with Tango assays and shortened immobility time in the forced swim test. The preliminary mechanism-of-action investigation manifested that the antidepressant activity of compound 18 may be mediated by promoting serotonin (5-HT) and dopamine (DA) levels in the mice brain. Compound 18 also showed favorable pharmacokinetic profiles and low toxicity in vivo. These results suggest that compound 18 could be a potential antidepressant agent.

Two-month administration of methylphenidate improves olfactory sensitivity and suppresses appetite in individuals with obesity.

Olfaction contributes to feeding behaviour and is modulated by changes in dopamine levels. Methylphenidate (MPH) increases brain dopamine levels and has been shown to reduce appetite and promote weight loss in patients with attention deficit hyperactivity disorder. The objectives of this study were to test the effect of MPH on olfaction, appetite, energy intake, and body weight (BW) on individuals with obesity. In a randomized, double-blind study, 12 participants (age 28.9 ± 6.7 years) with a body mass index (BMI) of 36.1 ± 4.5kg/m2 were assigned to MPH (0.5mg/kg) (n= 5) or placebo (n= 7) twice daily for 2months. Appetite (visual analog scale), odour threshold (Sniffin' Sticks®), energy intake (food menu), and BW (DEXA scan) were measured at day1 and day60. MPH intake significantly increased odour threshold scores (6.3 ± 1.4 vs. 9.4 ± 2.1 and 7.9 ± 2.3 vs. 7.8 ± 1.9, respectively; p= 0.029) versus placebo. There was a significantly greater suppression of appetite sensations (desire to eat (p= 0.001), hunger (p= 0.008), prospective food consumption (p= 0.003)) and an increase in fullness (p= 0.028) over time in the MPH versus placebo. MPH suppressed appetite and improved olfactory sensitivity in individuals with obesity. These data provide novel findings on the favourable effects of MPH on appetite and weight regulation in individuals living with obesity.

A Zebrafish Model of Neurotoxicity by Binge-Like Methamphetamine Exposure.

Hyperthermia is a common confounding factor for assessing the neurotoxic effects of methamphetamine (METH) in mammalian models. The development of new models of methamphetamine neurotoxicity using vertebrate poikilothermic animals should allow to overcome this problem. The aim of the present study was to develop a zebrafish model of neurotoxicity by binge-like methamphetamine exposure. After an initial testing at 20 and 40 mg/L for 48 h, the later METH concentration was selected for developing the model and the effects on the brain monoaminergic profile, locomotor, anxiety-like and social behaviors as well as on the expression of key genes of the catecholaminergic system were determined. A concentration- and time-dependent decrease in the brain levels of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) was found in METH-exposed fish. A significant hyperactivity was found during the first hour of exposure, followed 3 h after by a positive geotaxis and negative scototaxis in the novel tank and in the light/dark paradigm, respectively. Moreover, the behavioral phenotype in the treated fish was consistent with social isolation. At transcriptional level, th1 and slc18a2 (vmat2) exhibited a significant increase after 3 h of exposure, whereas the expression of gfap, a marker of astroglial response to neuronal injury, was strongly increased after 48 h exposure. However, no evidences of oxidative stress were found in the brain of the treated fish. Altogether, this study demonstrates the suitability of the adult zebrafish as a model of METH-induced neurotoxicity and provides more information about the biochemical and behavioral consequences of METH abuse.

Brain injury and inflammation genes common to a number of neurological diseases and the genes involved in the genesis of GABAnergic neurons are altered in monoamine oxidase B knockout mice

Monoamine oxidase B (MAO B) oxidizes trace amine phenylethylamine (PEA), and neurotransmitters serotonin and dopamine in the brain. We reported previously that PEA levels increased significantly in all brain regions, but serotonin and dopamine levels were unchanged in MAO B knockout (KO) mice. PEA and dopamine are both synthesized from phenylalanine by aromatic L-amino acid decarboxylase in dopaminergic neurons in the striatum. A high concentration of PEA in the striatum may cause dopaminergic neuronal death in the absence of MAO B. We isolated the RNA from brain tissue of MAO B KO mice (2-month old) and age-matched wild type (WT) male mice and analyzed the altered genes by Affymetrix microarray. Differentially expressed genes (DEGs) in MAO B KO compared to WT mice were analyzed by Partek Genomics Suite, followed by Ingenuity Pathway Analysis (IPA) to assess their functional relationships. DEGs in MAO B KO mice are involved in brain inflammation and the genesis of GABAnergic neurons. The significant DEGs include four brain injury or inflammation genes (upregulated: Ido1, TSPO, AVP, Tdo2), five gamma-aminobutyric acid (GABA) receptors (down-regulated: GABRA2, GABRA3, GABRB1, GABRB3, GABRG3), five transcription factors related to adult neurogenesis (upregulated: Wnt7b, Hes5; down-regulated: Pax6, Tcf4, Dtna). Altered brain injury and inflammation genes in MAO B knockout mice are involved in various neurological disorders: attention deficit hyperactive disorder, panic disorder, obsessive compulsive disorder, autism, amyotrophic lateral sclerosis, Parkinson’s diseases, Alzheimer’s disease, bipolar affective disorder. Many were commonly involved in these disorders, indicating that there are overlapping molecular pathways.

Performance, Carcass Yield, Muscle Amino Acid Profile, and Levels of Brain Neurotransmitters in Aged Laying Hens Fed Diets Supplemented with Guanidinoacetic Acid.

Simple SummaryIn commercial laying hens, aging is associated with a lower egg production rate and the marketing of spent hen carcasses shows some difficulty, probably due to the expected low meat yield. Using these hens as whole carcasses or to produce meat products for large-scale consumption could provide economic benefits to the poultry markets in developing countries. Thus, the aim of this study was to investigate the effect of dietary supplementation with guanidinoacetic acid (GA) on the carcass yield and muscle amino acid profile of aged laying hens. Dietary GA supplements were shown to improve the carcass yield and the levels of essential amino acids in the breast and thigh muscles of laying hens.Guanidinoacetic acid (GA) is a natural precursor of creatine in the body and is usually used to improve the feed conversion and cellular energy metabolism of broiler chickens. The objective was to elucidate the effect of dietary supplementation of GA on carcass yield, muscle amino acid profile, and concentrations of brain neurotransmitters in laying hens. In total, 128 72-week-old ISA Brown laying hens were assigned to four equal groups (32 birds, eight replicates per group). The control group (T1) was fed a basal diet with no supplements, while the other experimental groups were fed a basal diet supplemented with 0.5 (T2), 1.0 (T3), and 1.5 (T4) g GA kg−1 diet. The T3 and T4 groups showed higher hen-day egg production and carcass yield compared to the control group (p = 0.016 and 0.039, respectively). The serum creatine level increased linearly with the increased level of dietary GA (p = 0.007). Among the essential amino acids of breast muscle, a GA-supplemented diet linearly increased the levels of leucine, isoleucine, phenylalanine, methionine, and threonine in the breast (p = 0.003, 0.047, 0.001, 0.001, and 0.015, respectively) and thigh (p = 0.026, 0.001, 0.020, 0.009, and 0.028, respectively) muscles. GA supplementation linearly reduced the level of brain serotonin compared to the control group (p = 0.010). Furthermore, supplementation of GA in the diet of laying hens linearly increased the level of brain dopamine (p = 0.011), but reduced the level of brain Gamma-aminobutyric acid (p = 0.027). Meanwhile, the concentration of brain nitric oxide did not differ between the experimental groups (p = 0.080). In conclusion, the dietary supplementation of GA may improve the carcass yield and levels of essential amino acids in the breast muscles, as well as the brain neurotransmitters in aged laying hens.

Alcohol exposure increases manganese accumulation in the brain and exacerbates manganese-induced neurotoxicity in mice.

Environmental and occupational exposure to heavy metals remains one of the major concerns in public health. Increased levels of manganese (Mn) pollution are associated with profound neurotoxic effects, including neurobehavioral deficits and disturbances resembling Parkinson's disease. While Mn absorption is in part mediated by iron transporters, recent studies have shown that the levels of iron transporters are modified by alcohol and that chronic alcohol consumption increases body iron stores. However, it is largely unexplored whether alcohol exposure influences the transport and neurotoxicity of Mn. To address this question, we exposed mice to ethanol (10%; v/v) by drinking water for 4weeks, during which period MnCl2 (5mg/kg) or saline solutions were administered daily by intranasal instillation. Ethanol consumption in mice increased brain Mn levels in a dose-dependent manner after Mn instillation, determined by inductively-coupled plasma mass spectrometry, which was accompanied by up-regulation of iron transporters, as assessed by western blotting and qPCR. In addition, alcohol drinking increased hypoxic response and decreased hepcidin expression, providing the molecular mechanism of increased iron transporters and Mn uptake upon alcohol consumption. Moreover, brain dopamine levels, analyzed by HPLC, were decreased after intranasal Mn instillation, which was worsened by alcohol. Likewise, alcohol-Mn co-exposure synergistically altered dopaminergic protein expression. Finally, alcohol binge-drinking, which resembles alcohol drinking manner in humans, increased brain Mn content along with upregulation of iron transporters. Our study suggests that individuals who consume alcohol may have a higher risk of Mn neurotoxicity upon Mn exposure.

Effects of Sex and Group Size on Behavior and Brain Biogenic Amines in Short-Lived Turquoise Killifish (Nothobranchius furzeri).

Short-lived turquoise killifish (Nothobranchius furzeri) becomes a popular model species for neuroscience. However, the effects of sex and rearing conditions on behavior and brain monoamines in N. furzeri are unknown. In this article, we study the body mass, behavior in the novel tank diving test, levels of noradrenaline (NA), dopamine (DA), serotonin (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindoleacetic acid (5-HIAA) in the brain of 108 day-old N. furzeri males and females reared in small (one male and one or two females in 4-L tanks) and large (four males and four females in 25-L tanks) groups. Males were heavier and had a lower NA level in the brain compared with females. The behavior of males and females did not differ in the novel tank diving test. Their DA, 5-HT, DOPAC, and 5-HIAA levels in the brain did not differ too. Males from small groups spent more time near the tank's bottom. Rearing in small groups reduced the DA level in the female brain and the DOPAC level in female and male brains. However, group size did not affect body mass, 5-HT and 5-HIAA levels in the brain. Thus, group size is important for behavior and neuroscience studies of N. furzeri.

Regulation of dopamine production in the brains during sexual maturation in male honey bees

To explore the physiological mechanisms that underlie age-related dopamine increases during sexual maturation in the brains of male honey bees, we focused on the expression of genes encoding the enzymes tyrosine hydroxylase (Amth) and DOPA decarboxylase (Amddc), which are involved in dopamine biosynthesis in the brain. We hypothesized that juvenile hormone in hemolymph and tyrosine intake from food known as factors enhancing brain dopamine levels might both control the expression of genes related to dopamine production, and we tested this hypothesis in experiments. The brain levels of tyrosine and DOPA, which are precursors of dopamine, decreased as males aged, whereas the dopamine levels increased, suggesting active metabolism of dopamine precursors. The relative expression levels of Amth and Amddc were significantly higher in the brains of 4-day-old males compared with 0-day-old males, and the higher level of Amddc was maintained after 8 days. Topical application of the juvenile hormone analog methoprene enhanced the expression levels of Amth and Amddc in the brains according to the methoprene concentration. Oral intake of tyrosine enhanced the tyrosine, DOPA and dopamine levels in the brain, and activated Amddc expression in the brain, suggesting that tyrosine intake can increase both substrates and enzyme for dopamine biosynthesis. These results support our hypothesis that juvenile hormone and tyrosine intake may enhance the expression levels of genes encoding enzymes involved in dopamine biosynthesis in male honey bee brains during sexual maturation.

The Potential Effect of Mucuna pruriens Seed Extract on Sperm Quality experimental study on mice exposed to cigarette smoke

Background: Infertility has been more common problems among couple of reproductive age. One of the factors causing this disorder is unhealthy environmental factors including exposure to cigarette smoke. Polynuclear aromatic hydrocarbons (PAHs) in cigarette smoke can cause testicular atrophy, while the free radicals can inhibit the stages of spermatogenesis, and nicotine in cigarettes affects the brain dopamine levels affecting the levels of GnRH, and subsequently affect the levels of FSH and LH needed in spermatogenesis. The use of Mucuna pruriens seed extract containing antioxidants and L-dopa is expected to improve the quality of sperm after exposure to cigarette smoke.&#x0D; Objective: This study aimed to determine the effect of Mucuna pruriens seed extract on the sperm quality in mice exposed to cigarette smoke.&#x0D; Methods: This study was an experimental study with a post test only control group design. A total of 20 mice were divided into 4 groups of five mice each. All groups were exposed to cigarette smoke. Group 1 was the negative control exposed to cigarette smoke. Groups 2, 3, 4 were exposed to cigarettes smoke and given Mucuna pruriens seed extracts at the dose of 250; 300; and 350 mg/Kg BW/day. Parameters of sperm quality included concentration, morphology, motility and viability.&#x0D; Results: Post hoc tests showed there were significant differences among treatment groups.&#x0D; Conclusion: the administration of Mucuna pruriens seed extract affects the sperm quality of BALB/c mice exposed to cigarettes smoke.&#x0D; Bangladesh Journal of Medical Science Vol.20(4) 2021 p.768-773