Anxiolytic activity of Indian Abies pindrow Royle leaves in rodents: an experimental study

Putative anxiolytic activity of ethanolic extract of Indian A. pindrow Royle leaf was investigated in rats using various experimental paradigms of anxiety viz. open field exploratory behaviour, elevated plus maze (EPM) and elevated zero maze (EZM) tests. Pilot studies indicated that single dose administration of extract had little to no acute behavioural effects, hence the extract was administered orally at different dose levels once daily for three consecutive days, while lorazepam (LR) (0.5 mg/kg, i.p.) was administered acutely. Ethanolic extract of A. pindrow (AP) leaves (50 and 100 mg/kg, p.o.) showed significant anxiolytic effects on all the paradigms of anxiety. The results indicate that AP and LR induced a significant increase in open field ambulation and slight increase in rearings and activity in center, whereas grooming and faecal droppings remain unchanged. In EPM, significant augmentation of open arm entries, and time spent on open arms was noted in AP treated rats. In EZM test, significant increase in time spent on open arms and entries in open arms was observed, whereas slight increase in head dips and stretched attend postures was also observed. The AP extract showed consistent and significant anxiolytic activity in all the tests. The effects induced by ethanolic extract of AP were less marked than those of lorazepam were.     

Anxiolytic activity of Indian Hypericum perforatum Linn: an experimental study

The putative anxiolytic activity of 50% ethanolic extract of Indian Hypericum perforatum (IHp) was investigated in rats using various experimental paradigms of anxiety viz. open field exploratory behaviour (OFB), elevated plus maze (EPM), elevated zero maze (EZM), novelty induced suppressed feeding latency (FL) and social interaction (SI) tests. Pilot studies indicated that single dose administration of IHp had little to no acute behavioural effects, hence the extract of IHp was administered orally at different dose levels once daily for three consecutive days, while lorazepam (LR) (0.5 mg/kg, i.p.) was administered acutely. IHp extract (100 and 200 mg/kg, p.o.) showed significant anxiolytic effects on all the paradigms of anxiety. The results indicate that IHp and LR induced a significant increase in open field ambulation and slight increase in rearings and activity in centre, whereas grooming and fecal droppings remain unchanged. In EPM, significant augmentation of open arm entries, open arm/closed arm entries ratio and time spent on open arms was noted in IHp treated rats. In EZM test, significant increase in time spent on open arms and entries in open arms were observed, whereas slight increase in head dips and stretched attend postures were also observed. IHp and LR significantly attenuated the novelty induced increase in feeding latency. IHp treated rats also showed significant increase in social interaction in the novel environment. The IHp extracts showed consistent and significant anxiolytic activity in all the tests. The effects induced by 50% ethanolic extract of IHp were less marked than those of lorazepam were.     

Different effects of subchronic doses of 17-beta estradiol in two ethologically based models of anxiety utilizing female rats

Estrogen may have differing effects on 'anxiety' responses under different conditions. The current study tested the effects of estrogen on anxiety-like behavior when administered for 6-7 days in ovariectomized (OVX) female rats. Two animal paradigms were utilized; the elevated plus maze (EPM), measuring changes in innate fear of exploration of open spaces; and the social interaction test (SIT), measuring the exploration of a novel, same gender partner. In the EPM, estradiol-treated OVX females both entered and spent more time in the open arms than control OVX females, indicating an anxiolytic-like action of estradiol. In contrast, estradiol treated OVX females interacted less with the partner animal in the SIT compared with controls suggesting anxiogenic-like effects. The possible anxiogenic effect of estradiol in the SIT is supported by two findings: (1) the effect is reversed by the anxiolytic drug alprazolam and (2) estrogen did not affect locomotion and therefore, the reduced social interaction is not due to reduced activity. Acute administration of progesterone (5 mg/kg), which has anxiolytic properties, did not reverse estradiol-induced social interaction deficits, suggesting that lack of progesterone did not account for estradiol's anxiogenic effects. These results, while seemingly contradictory when interpreted within a unified concept of anxiety, may well reflect the ethological roles of reproductive hormones and their effects on different types of exploratory anxiety.     

Role of learning of open arm avoidance in the phenomenon of one-trial tolerance to the anxiolytic effect of chlordiazepoxide in mice

A single exposure to the elevated plus-maze (EPM) test of anxiety reduces or abolishes the anxiolytic efficacy of benzodiazepines on a second trial. Some possible explanations to the occurrence of this phenomenon (one-trial tolerance-OTT) involve behavioral modifications thought to be consequence of some kind of learning in the first trial. In the present study, the influence of learning-impairing situations on the effects of the benzodiazepine chlordiazepoxide on mice re-tested in the EPM is investigated. The results showed that: (1) as expected, the administration of chlordiazepoxide to mice re-tested in the EPM- under the same conditions of the first trial- failed to induce anxiolysis; (2) a decreased percent time in the open arms was observed on the second trial of mice exposed to both trials under the same experimental conditions; (3) neither the increase in open arm avoidance by mice re-exposed to the EPM nor the OTT to chlordiazepoxide effect were modified by administration of the amnestic agent scopolamine; (4) the decrement of the duration of the first trial to 1 min or the change in light and noise conditions in both trials counteracted the increase in open arm avoidance on trial 2; (5) none of the later procedures modified the phenomenon of OTT. Although not discarding the modulation exerted by other memory processes in the OTT phenomenon, the results indicate that situations that impair the learned avoidance response to the open arms in the EPM do not modify the phenomenon of OTT.     

Apigenin 7-glucoside from Stachys tibetica Vatke and its anxiolytic effect in rats

BackgroundStachys tibetica Vatke (Himalayan or mountain tea) grows abundantly in the tropical and subtropical locations of the world including India, Tibet and China. The traditional healers of Kargil and adjoining areas in Ladakh, Jammu and Kashmir in India use the drug to treat fever, cough, phobias and various mental disorders etc. in the form of a decoction or as a tea. Flavonoids are important components in most herbal teas and play an important role in the management of various brain disorders via mimicking the action of benzodiazepines or through benzodiazepine receptors.Aim of the studyThe present study aimed to isolate flavonoids from S. tibetica and to evaluate their anxiolytic potential in comparison to reference synthetic (diazepam) and natural (apigenin) molecules.Materials and methodsS. tibetica root powder was extracted with 95% methanol for about 72 h using a soxhlet apparatus and the resultant extract was subjected to isolation procedures, resulting in the isolation of apigenin 7-glucoside and characterisation by various physical and spectrometric analyses. Apigenin 7-glucoside was evaluated for anxiolytic activity in rats in comparison with the reference compounds diazepam and apigenin using the elevated plus maze (EPM) model.ResultsPhytochemical investigations of S. tibetica revealed the presence of tannins, phenolics, flavonoids, saponins, glycosides and carbohydrates. A flavonoid glucoside, apigenin 7-glucoside was isolated for the first time from the roots of S. tibetica Vatke. The percentage of time spent and arm entries in the open arms was increased while the arms entries and duration of time spent in closed arms were decreased in the groups treated with apigenin 7-glucoside (which dose). In a similar fashion, diazepam and apigenin also exhibited anxiolytic activity (*p < 0.05, **p < 0.01). Apigenin 7-glucoside significantly decreased the percentage of head dips in EPM. Apigenin 7-glucoside showed anxiolytic potential comparable to the reference drugs apigenin and diazepam.ConclusionApigenin 7-glucoside could be an important molecule for the treatment of anxiety and further studies are required to elucidate its possible mechanism of action.     

Progesterone modulation of α5 nAChR subunits influences anxiety‐related behavior during estrus cycle

Smokers often report an anxiolytic effect of cigarettes. In addition, stress‐related disorders such as anxiety, post‐traumatic stress syndrome and depression are often associated with chronic nicotine use. To study the role of the α5 nicotinic acetylcholine receptor subunit in anxiety‐related responses, control and α5 subunit null mice (α5^?/?) were subjected to the open field activity (OFA), light–dark box (LDB) and elevated plus maze (EPM) tests. In the OFA and LDB, α5^?/? behaved like wild‐type controls. In the EPM, female α5^?/? mice displayed an anxiolytic‐like phenotype, while male α5^?/? mice were undistinguishable from littermate controls. We studied the hypothalamus–pituitary–adrenal axis by measuring plasma corticosterone and hypothalamic corticotropin‐releasing factor. Consistent with an anxiolytic‐like phenotype, female α5^?/? mice displayed lower basal corticosterone levels. To test whether gonadal steroids regulate the expression of α5, we treated cultured NTera 2 cells with progesterone and found that α5 protein levels were upregulated. In addition, brain levels of α5 mRNA increased upon progesterone injection into ovariectomized wild‐type females. Finally, we tested anxiety levels in the EPM during the estrous cycle. The estrus phase (when progesterone levels are low) is anxiolytic‐like in wild‐type mice, but no cycle‐dependent fluctuations in anxiety levels were found in α5^?/? females. Thus, α5‐containing neuronal nicotinic acetylcholine receptors may be mediators of anxiogenic responses, and progesterone‐dependent modulation of α5 expression may contribute to fluctuations in anxiety levels during the ovarian cycle.     

One-trial tolerance to the effects of chlordiazepoxide in the elevated plus-maze is not due to acquisition of a phobic avoidance of open arms during initial exposure

A single exposure to the elevated plus-maze (EPM) test of anxiety reduces or abolishes the anxiolytic-like efficacy of benzodiazepines. This phenomenon called one-trial tolerance has been suggested to represent the acquisition of a phobic-like response to the open arms during trial 1. The present study was designed to examine the effects of chlordiazepoxide (5 mg/kg, ip) on the behaviour of rats in a conventional EPM apparatus after previous exposure to a four-open-arm EPM, a four-enclosed arm EPM or a conventional EPM, as well as in naive rats. Chlordiazepoxide had clear-cut anxiolytic-like effects (increased percentage of time spent on the open arms) in a traditional EPM in naive rats and in animals previously exposed to a four-open-arm EPM. However, it was ineffective in rats previously exposed to a traditional or a four-closed-arm EPM. Thus, the phenomenon of one-trial tolerance does not depend upon initial open-arm experience.     

Dynamic metabonomic responses of tobacco (Nicotiana tabacum) plants to salt stress

Metabolic responses are important for plant adaptation to osmotic stresses. To understand the dosage and duration dependence of salinity effects on plant metabolisms, we analyzed the metabonome of tobacco plants and its dynamic responses to salt treatments using NMR spectroscopy in combination with multivariate data analysis. Our results showed that the tobacco metabonome was dominated by 40 metabolites including organic acids/bases, amino acids, carbohydrates and choline, pyrimidine, and purine metabolites. A dynamic trajectory was clearly observable for the tobacco metabonomic responses to the dosage of salinity. Short-term low-dose salt stress (50 mM NaCl, 1 day) caused metabolic shifts toward gluconeogenesis with depletion of pyrimidine and purine metabolites. Prolonged salinity with high-dose salt (500 mM NaCl) induced progressive accumulation of osmolytes, such as proline and myo-inositol, and changes in GABA shunt. Such treatments also promoted the shikimate-mediated secondary metabolisms with enhanced biosynthesis of aromatic amino acids. Therefore, salinity caused systems alterations in widespread metabolic networks involving transamination, TCA cycle, gluconeogenesis/glycolysis, glutamate-mediated proline biosynthesis, shikimate-mediated secondary metabolisms, and the metabolisms of choline, pyrimidine, and purine. These findings provided new insights for the tobacco metabolic adaptation to salinity and demonstrated the NMR-based metabonomics as a powerful approach for understanding the osmotic effects on plant biochemistry.     

Behavioural evaluation of methods for assessing fear responses in weaned pigs

Models of anxiety and fear of novelty were evaluated using correlations and principal component analysis. A total of 84 pigs (LandracexYorkshire) from nine different litters were subjected to a tonic immobility (TI) test at the age of 2.5 weeks, an elevated plus-maze (EPM) at the age of 6 weeks, a light/dark (L/D) exploration test at the age of 7 weeks and an open-field (OF) test at the age of 8 weeks.The first component from the principal component analysis had the highest correlation with number of entries into open arms in the EPM but was also highly correlated to variables from the other three tests confirming a common aversion-related element in the four experimental tests. The second component was negatively correlated with percent entries into and time spent on open arms in the EPM, but positively correlated with the number of entries into closed arms in the same test, number of lines crossed in the OF and time spent in the lit compartment of the L/D test. The last point illustrates a negative relationship between "anxiety" and "activity" in the EPM and OF. To achieve purer measures of fear of novelty and activity in the tests, the components were rotated using the Varimax criterion. The rotated factor pattern demonstrated a simple structure where variables related to "anxiety" or "fear of novelty" (i.e., percent entries into open arms and time spent on open arms of the EPM) had the highest loading on factor 1, whereas variables related to activity (i.e., number of entries into the closed arms in the EPM, number of lines crossed in the OF and time spent in the lit compartment of the L/D test) had the highest loading on factor 2. TI duration loaded more strongly on factor 1 ("fear of novelty") than on factor 2 ("activity"), but did not represent any pure measure of either fear of novelty or activity.In conclusion, all of the test variables were related to one another. Open-arm avoidance represented the purest measure of fear of novelty, whereas entries into closed arms and number of lines crossed in the OF were the purest measures of activity. The EPM appeared to provide the best way to separate the fear of novelty and activity-related elements, indicating that the EPM may be a useful behavioural model of fear of novelty or avoidance in pigs.     

Effect of electrical stimulation of the baso-lateral amygdala nucleus on defensive burying shock probe test and elevated plus maze in rats

In the present report, the putative effect of a single electrical stimulation (75, 150 or 300 microA) to the baso-lateral amygdala (BLA) nucleus was assessed in shock probe defensive burying behavior test (DB) and elevated plus maze (EPM). These models have been used for measuring anxiety levels and screening putative anxiolytic compounds. A group of 28 rats were randomly divided for the following experimental conditions: Control-control, sham-operated, BLA stimulated groups: 75, 150 and 300 microA tested for DB. The cumulative defensive burying in a 15 min-test, the latency of burying, the number of shock received and the height of the bedding material in the probe were recorded. Another group of 28 individuals was also randomly distributed for the following experimental conditions: Control-control, sham-operated, BLA stimulated animals: 75, 150, 300 microA and tested in the EPM. The time the subjects spent in the open arms, the crosses and the faeces number excreted during the test were recorded. Decreased levels of defensive burying were observed in 75, 150 and 300 microA stimulated groups. The 150 and 300 microA groups reached statistical significance. The fact that 300 microA stimulated group showed statistically significant increase in the latency of defensive burying, in the number of shock received and decreased amount in bedding material suggests a sedative action of electrical stimulation. Increased time in the open arms and augmented number of crossings in 150 microA group was observed. No changes in the number of faeces were observed in any group. The evidence supported the notion of an inhibitory amygdaline mechanism triggered by sub-threshold electrical stimulation.     

小鼠动物实验方法系列专题(五) 应用高架十字迷宫分析小鼠焦虑行为

高架十字迷宫(the elevated plus maze,EPM)是研究小鼠焦虑行为的重要实验,本文介绍了EPM的原理和实验步骤。将小鼠置于开臂闭臂接合处,面向开臂,通过录像记录分析小鼠在EPM的表现。结果发现,两种小鼠均可成功完成实验,C57小鼠在EPM内较不活跃,闭臂滞留时间占总时间百分比显著高于129Sv小鼠。应用EPM可以简单直观地分析小鼠焦虑行为。     

Anxiolytic-like effects of extracts from Albizzia julibrissin bark in the elevated plus-maze in rats

The purpose of the this study was to characterize the putative anxiolytic-like effects of the aqueous extract of Albizzia julibrissin stem bark using the elevated plus maze (EPM) in rats. The water extract of Albizzia julibrissin was orally administered at 10, 50, 100 or 200 mg/kg to adult male SD rats, 1 h before behavioral evaluation in an EPM, respectively. Control rats were treated with an equal volume of saline, and positive control rats buspirone (1 mg/kg). Single or repeated treatment (for 7 days) of the water extract of Albizzia julibrissin (at 100 or 200 mg/kg) significantly increased time-spent and arm entries into the open arms of the EPM, and decreased time-spent and arm entries in the closed arms of the EPM versus saline controls (P < 0.05). However, no changes in the locomotor activity and myorelaxant effect were seen in any group versus the saline control. In addition, the anxiolytic-like effects of Albizzia julibrissin extract were abolished by pindolol (10 mg/kg, i.p), a 5-HT(1A/1B) receptor antagonist. These results suggest that Albizzia julibrissin might proved to be an effective anxiolytic agent, and that it acts via the serotonergic nervous system.     

Metabolic biomarkers of prenatal disorders: an exploratory NMR metabonomics study of second trimester maternal urine and blood plasma

This work describes an exploratory NMR metabonomic study of second trimester maternal urine and plasma, in an attempt to characterize the metabolic changes underlying prenatal disorders and identify possible early biomarkers. Fetal malformations have the strongest metabolic impact in both biofluids, suggesting effects due to hypoxia (leading to hypoxanthine increased excretion) and a need for enhanced gluconeogenesis, with higher ketone bodies (acetone and 3-hydroxybutyric acid) production and TCA cycle demand (suggested by glucogenic amino acids and cis-aconitate overproduction). Choline and nucleotide metabolisms also seem affected and a distinct plasma lipids profile is observed for mothers with fetuses affected by central nervous system malformations. Urine from women who subsequently develop gestational diabetes mellitus exhibits higher 3-hydroxyisovalerate and 2-hydroxyisobutyrate levels, probably due to altered biotin status and amino acid and/or gut metabolisms (the latter possibly related to higher BMI values). Other urinary changes suggest choline and nucleotide metabolic alterations, whereas lower plasma betaine and TMAO levels are found. Chromosomal disorders and pre-preterm delivery groups show urinary changes in choline and, in the latter case, in 2-hydroxyisobutyrate. These results show that NMR metabonomics of maternal biofluids enables the noninvasive detection of metabolic changes associated to prenatal disorders, thus unveiling potential disorder biomarkers.     

Pain-related anxiety-like behavior requires CRF1 receptors in the amygdala

Corticotropin-releasing factor receptor CRF1 has been implicated in the neurobiological mechanisms of anxiety and depression. The amygdala plays an important role in affective states and disorders such as anxiety and depression. The amygdala is also emerging as a neural substrate of pain affect. However, the involvement of the amygdala in the interaction of pain and anxiety remains to be determined. This study tested the hypothesis that CRF1 receptors in the amygdala are critically involved in pain-related anxiety. Anxiety-like behavior was determined in adult male rats using the elevated plus maze (EPM) test. The open-arm preference (ratio of open arm entries to the total number of entries) was measured. Nocifensive behavior was assessed by measuring hindlimb withdrawal thresholds for noxious mechanical stimulation of the knee. Measurements were made in normal rats and in rats with arthritis induced in one knee by intraarticular injections of kaolin/carrageenan. A selective CRF1 receptor antagonist (NBI27914) or vehicle was administered systemically (i.p.) or into the central nucleus of the amygdala (CeA, by microdialysis). The arthritis group showed a decreased preference for the open arms in the EPM and decreased hindlimb withdrawal thresholds. Systemic or intraamygdalar (into the CeA) administration of NBI27914, but not vehicle, inhibited anxiety-like behavior and nocifensive pain responses, nearly reversing the arthritis pain-related changes. This study shows for the first time that CRF1 receptors in the amygdala contribute critically to pain-related anxiety-like behavior and nocifensive responses in a model of arthritic pain. The results are a direct demonstration that the clinically well-documented relationship between pain and anxiety involves the amygdala.     

Asparagus racemosus Attenuates Anxiety-Like Behavior in Experimental Animal Models

Asparagus racemosus Linn. (AR) is used worldwide as a medicinal plant. In the present study, the anxiolytic activity of standardized methanolic extract of root of AR (MAR) was evaluated in open-field test (OFT), hole-board, and elevated plus maze (EPM) tests. Rats received oral pretreatment of MAR in the doses of 50, 100, and 200 mg/kg daily for 7 days and then were evaluated for the anxiolytic activity in different animal models. Both MAR (100 and 200 mg/kg) and diazepam (1 mg/kg, p.o.) increased the grooming behavior, number of central squares crossed, and time spent in the central area during OFT. Further, MAR (100 and 200 mg/kg) increased the head-dip and head-dip/sniffing behavior, and decreased sniffing activity in hole-board test. Furthermore, MAR (100 and 200 mg/kg) increased the percentage entries and time spent to open arm in EPM test paradigm. The anxiolytic activity in the experimental models was similar to that of diazepam. MAR (100 and 200 mg/kg) enhanced the level of amygdalar serotonin and norepinephrine. It also increased the expression of 5-HT_2A receptors in the amygdala. In another set of experiment, flumazenil attenuated the anxiolytic effect of minimum effective dose of MAR (100 mg/kg) in OFT, hole-board, and EPM tests, indicating GABA_A-mediated mechanism. Moreover, the anxiolytic dose of MAR did not show sedative-like effect in OFT and EPM tests compared to diazepam (6 mg/kg, p.o.). Thus, the anxiolytic response of MAR may involve GABA and serotonergic mechanisms. These preclinical data show that AR can be a potential agent for treatment of anxiety disorders.     

Influence of omega-3 Fatty Acid status on the way rats adapt to chronic restraint stress

Omega-3 fatty acids are important for several neuronal and cognitive functions. Altered omega-3 fatty acid status has been implicated in reduced resistance to stress and mood disorders. We therefore evaluated the effects of repeated restraint stress (6 h/day for 21 days) on adult rats fed omega-3 deficient, control or omega-3 enriched diets from conception. We measured body weight, plasma corticosterone and hippocampus glucocorticoid receptors and correlated these data with emotional and depression-like behaviour assessed by their open-field (OF) activity, anxiety in the elevated-plus maze (EPM), the sucrose preference test and the startle response. We also determined their plasma and brain membrane lipid profiles by gas chromatography. Repeated restraint stress caused rats fed a control diet to lose weight. Their plasma corticosterone increased and they showed moderate behavioural changes, with increases only in grooming (OF test) and entries into the open arms (EPM). Rats fed the omega-3 enriched diet had a lower stress-induced weight loss and plasma corticosterone peak, and reduced grooming. Rats chronically lacking omega-3 fatty acid exhibited an increased startle response, a stress-induced decrease in locomotor activity and exaggerated grooming. The brain omega-3 fatty acids increased as the dietary omega-3 fatty acids increased; diets containing preformed long-chain omega-3 fatty acid were better than diets containing the precursor alpha-linolenic acid. However, the restraint stress reduced the amounts of omega-3 incorporated. These data showed that the response to chronic restraint stress was modulated by the omega-3 fatty acid supply, a dietary deficiency was deleterious while enrichment protecting against stress.     

The footprints of gut microbial-mammalian co-metabolism

Gut microbiota are associated with essential various biological functions in humans through a "network" of microbial-host co-metabolism to process nutrients and drugs and modulate the activities of multiple pathways in organ systems that are linked to different diseases. The microbiome impacts strongly on the metabolic phenotypes of the host, and hence, metabolic readouts can give insights into functional metagenomic activity. We applied an untargeted mass spectrometry (MS) based metabonomics approach to profile normal Wistar rats exposed to a broad spectrum β-lactam antibiotic imipenem/cilastatin sodium, at 50 mg/kg/daily for 4 days followed by a 14-day recovery period. In-depth metabolic phenotyping allowed identification of a panel of 202 urinary and 223 fecal metabolites significantly related to end points of a functional metagenome (p < 0.05 in at least one day), many of which have not been previously reported such as oligopeptides and carbohydrates. This study shows extensive gut microbiota modulation of host systemic metabolism involving short-chain fatty acids, tryptophan, tyrosine metabolism, and possibly a compensatory mechanism of indole-melatonin production. Given the integral nature of the mammalian genome and metagenome, this panel of metabolites will provide a new platform for potential therapeutic markers and mechanistic solutions to complex problems commonly encountered in pathology, toxicology, or drug metabolism studies.     

采用代谢组学分析技术分析工业啤酒发酵过程中风味物质生成规律

啤酒风味是保证啤酒品质的关键因素之一。运用代谢组学的方法,分析工业啤酒发酵过程中酵母胞内代谢物和啤酒风味物质的对应关系,从代谢水平上研究风味物质形成过程中的关键影响因素。在啤酒发酵过程中,同时检测风味物质的含量变化和酵母胞内代谢物的变化,对得到海量的、多维的代谢数据采用主成分分析（PCA）和偏最小二乘分析（PLS）的多元统计分析方法进行处理。由PCA分析结果可知：磷酸、海藻糖、琥珀酸、谷氨酸、天冬氨酸、丙氨酸对主成分贡献比较大,说明这些代谢物在不同发酵阶段含量变化显著。由PLS分析结果可知：对啤酒风味影响最大的物质主要为氨基酸,包括丝氨酸、缬氨酸、苏氨酸、赖氨酸、丙氨酸、亮氨酸和天冬酰胺等,这为啤酒中风味物质的调控提供了一定的理论指导。     

不同年龄大鼠尿液代谢组学研究

旨在探究健康大鼠的尿液代谢物在生长、发育和衰老过程中的年龄相关性变化.采集大鼠出生后3周、5周、7周、9周、12周、56周和111周共7个年龄点的尿液样本,利用GC/TOF-MS平台进行代谢组学检测.结果显示,所有尿液样本在主成分分析与偏最小二乘法判别分析中出现组内聚类和组间分离.氨基酸类、有机酸类和碳水化合物类代谢物...     

Naltrexone potentiates both amnestic and anxiolytic effects of chlordiazepoxide in mice

Studies have suggested that opioid antagonists potentiate the anxiolytic effect but not the amnestic action of chlordiazepoxide (CDZ). We investigated the effects of naltrexone (NAL) on the anxiolytic and amnestic effects of CDZ in mice tested in the plus-maze discriminative avoidance task (DAT). Mice are conditioned to choose between two enclosed arms (one of which aversive) while avoiding the two open arms of the apparatus. This task measures memory (time spent in the aversive vs. time in the non-aversive enclosed arms) and anxiety (time spent in the open arms). Mice treated with saline (SAL) or 5 mg/kg NAL, and SAL or 2.5 mg/kg CDZ were submitted to DAT training. The test was performed 24 h later, without aversive stimuli. In the training, NAL + CDZ group showed higher percent time spent in the open arms than all the other groups. In the test, NAL + CDZ (but not SAL + CDZ) group showed higher percent time spent in the aversive enclosed arm than SAL + SAL and NAL + SAL groups. The data suggest that NAL potentiates the small decreases in anxiety and retention induced by a subeffective dose of CDZ.