慢性束缚诱导的广泛性焦虑障碍前额叶皮质中miRNA的表达

摘要 目的：研究慢性束缚(Chronic restraint stress,CRS)诱导的广泛性焦虑障碍模型小鼠前额叶皮质miRNA表达谱的变化及其意义。方法：小鼠经过7天的CRS,通过旷场实验与高架十字迷宫实验检测小鼠是否能够表现出紧张和焦虑行为。采用高通量测序的方法,定量分析对照组与模型组小鼠前额叶皮质组织中 miRNAs的表达水平,研究CRS诱导的焦虑有关的分子表达谱。通过RT-PCR对测序结果中差异表达的miRNAs 进行验证。结果：经CRS诱导的广泛性焦虑障碍模型组小鼠,模型组在活动总距离增多（P＜0.05）、平均速度（P＜0.05）增快、中央停留时间减少（P＜0.05）、开放臂进入次数百分比减少（P<0.01）、开放臂停留时间减少（P＜0.01）,与对照组相比结果均具有统计学意义,表明GAD小鼠造模成功。经高通量测序结果及生信学分析,对照组与模型组相比较,共28个上调miRNAs,34个下调miRNAs,5388个靶基因参与作用变化。上/下调的miR-GO分析结果中,主要共同参与神经系统发育、突触后密度、神经元投射、蛋白丝氨酸/苏氨酸激酶活性等过程;上/下调miR-KEGG结果中,参与共同通路主要包括轴突引导、神经营养因子信号通路、cAMP 信号通路、多巴胺能突触、MAPK信号通路等过程。结论：前额叶皮质中miR-7a-5p、miR-124-3p、miR-141-3p、miR-183-5p等miRNA变化参与广泛性焦虑障碍的发病,可能调控影响神经传导等功能。     

The existence value of the Antillean manatee in the unprotected Hondo River (Mexico) as a fundamental component for its conservation

The Hondo River is the natural border between Mexico and Belize, and it is part of the distribution area of the Endangered Antillean manatee Trichechus manatus manatus. Currently, the Hondo River does not have any special protection. Employing qualitative research methods, we documented the social perception and local knowledge from riverside communities to assess conservation status and trends of manatees in the area. Fifty semi-structured interviews were carried out to river users in 16 Mexican communities, distributed in six segments along the riverbed. The claims of the inhabitants agree with boat-based surveys: most of the current and historical manatee sightings were reported in segments of the main watercourses, but also in small tributaries, which are usually shallow and rich in aquatic vegetation. Additionally, the local perception about manatee conservation status can be helpful to understand population trends and threats: 48 % of the interviewees claimed that nowadays the number of sighted manatees is less than that observed 10 years ago. The responders identified water pollution due to cane cultivation practices, motorized vessels traffic, and presence of fishing nets as potential threats to manatees. This study provides evidence of relevant local knowledge about the manatee ecology and its habitat, critical in the construction of binational conservation strategies for the species. Therefore, local resources users may play an increasingly significant role in manatee management and monitoring. Although manatees are poached for their meat in several areas of their distribution, the most common value attributed to manatees in Hondo River was non-use existence values. Local people recognize the challenges to observe this cryptic species in this river, but also identified manatees as potential flag species, suggesting that it may represent a valuable resource for ecotourism. We suggest that the non-extractive use of manatees has the potential for promoting species conservation and local economic growth.     

Chronic social defeat stress-induced enhancement of T-type calcium channels increases burst-firing neurons in the ventral subiculum

The ventral subiculum (vSub), a representative output structure of the hippocampus, serves as a main limbic region in mediating the brain's response to stress. There are three subtypes of subicular pyramidal neurons based on their firing patterns: regular-spiking (RS), weak-bursting (WB) and strong-bursting (SB) neurons, located differently along proximal–distal axis. Here, we found that chronic social defeat stress (CSDS) in mice increased the population of SB neurons but decreased RS neurons in the proximal vSub. Specific blockers of T-type calcium channels inhibited the burst firings with a concomitant reduction of afterdepolarization, suggesting that T-type calcium channels underlie the burst-spiking activity. Consistently, CSDS increased both T-type calcium currents and expression of Cav3.1 proteins, a subtype of T-type calcium channels, in the proximal vSub. Therefore, we conclude that CSDS-induced enhancement of Cav3.1 expression increased bursting neuronal population in the vSub, which may contribute to stress-related behaviors.     

Social media user’s knowledge on soil plant relationship in Saudi Arabia

The study aimed to investigate the soil-plant relationship by looking at knowledge levels of social media users. The study examined the relationship between the users’ characteristics and their knowledge on soil-plant relationship. Online survey was designed and distributed to gather the data. The number of response was received from 383 respondents where 375 participants provided completed information and the remaining eight responses were eliminated due to quality standards. The results show most of the participants (68.8%) are moderately depend on social media to acquire knowledge on soil-plant relationship and indicated “Twitter” as the highly utilized platform followed by the “Youtube”. Meanwhile, 48.8% of the participants indicated that social media have a high impact on their knowledge-based information on soil-plant relationship and agricultural contents. Inferential analysis shows there was a significant positive relationship (p < 0.01) between independent variables; Twitter, Youtube, Instagram, and Snapchat and the degree of trust on these platforms, and the level’s knowledge on soil-plant relationship (dependent variable). Only 13% of the variance accounted for the impact of social media on participants’ agricultural knowledge-base can be predicted from the combination of participants’ reliance on a set of social media platforms (Twitter, Instagram, Youtube, and Snapchat). The study revealed the trust and confidence of the users using social media on agricultural information/soil plant relationship had a medium effect in social and educational research.     

Anti-salmonella properties of kefir yeast isolates: An in vitro screening for potential infection control

The rise of antibiotic resistance has increased the need for alternative ways of preventing and treating enteropathogenic bacterial infection. Various probiotic bacteria have been used in animal and human. However, Saccharomyces boulardii is the only yeast currently used in humans as probiotic. There is scarce research conducted on yeast species commonly found in kefir despite its claimed potential preventative and curative effects. This work focused on adhesion properties, and antibacterial metabolites produced by Kluyveromyces lactis and Saccharomyces unisporus isolated from traditional kefir grains compared to Saccharomyces boulardii strains. Adhesion and sedimentation assay, slide agglutination, microscopy and turbidimetry assay were used to analyze adhesion of Salmonella Arizonae and Salmonella Typhimurium onto yeast cells. Salmonella growth inhibition due to the antimicrobial metabolites produced by yeasts in killer toxin medium was analyzed by slab on the lawn, turbidimetry, tube dilution and solid agar plating assays. Alcohol and antimicrobial proteins production by yeasts in killer toxin medium were analyzed using gas chromatography and shotgun proteomics, respectively. Salmonella adhered onto viable and non-viable yeast isolates cell wall. Adhesion was visualized using scanning electron microscope. Yeasts-fermented killer toxin medium showed Salmonella growth inhibition. The highest alcohol concentration detected was 1.55%, and proteins with known antimicrobial properties including cathelicidin, xanthine dehydrogenase, mucin-1, lactadherin, lactoperoxidase, serum amyloid A protein and lactotransferrin were detected in yeasts fermented killer medium. These proteins are suggested to be responsible for the observed growth inhibition effect of yeasts-fermented killer toxin medium. Kluyveromyces lactis and Saccharomyces unisporus have anti-salmonella effect comparable to Saccharomyces boulardii strains, and therefore have potential to control Salmonella infection.     

鸟类鸣声与个体适合度关系的研究进展

鸣声蕴藏着丰富的生物学信息,是鸟类间信息交流最主要的方式之一.本文综述了鸟类鸣声行为与包括个体状态(体征、激素水平和健康状况)、社会等级及繁殖(性选择和成效)在内的个体适合度关系的研究进展.文章总结发现,鸟类的鸣声水平与单一体征参数关系的研究结果不稳定,鸣声可能受个体内部的多种激素调控,并与个体的社会等级有直接关系.雌...     

Possible evidence for shift work schedules in the media workers of the ant species Camponotus compressus

The locomotor activity rhythm of the media workers of the ant species Camponotus compressus was monitored under constant conditions of the laboratory to understand the role of circadian clocks in social organization. The locomotor activity rhythm of most ants entrained to a 24 h light/dark (12:12 h; LD) cycle and free-ran under constant darkness (DD) with circadian periodicities. Under entrained conditions about 75% of media workers displayed nocturnal activity patterns, and the rest showed diurnal activity patterns. In free-running conditions these ants displayed three types of activity patterns (turn-around). The free-running period (τ) of the locomotor activity rhythm of some ants (10 out of 21) showed period lengthening, and those of a few (6 out of 21) showed period shortening, whereas the locomotor activity rhythm of the rest of the ants (5 out of 21) underwent large phase shifts. Interestingly, the pre-turn-around τ of those ants that showed nocturnal activity patterns during earlier LD entrainment was shorter than 24 h, which became greater than 24 h after 6-9 days of free-run in DD. On the other hand, the pre-turn-around τ of those ants, which exhibited diurnal patterns during earlier LD entrainment, was greater than 24 h, which became shorter than 24 h after 6-9 days of free-run in DD. The patterns of activity under LD cycles and the turn-around of activity patterns in DD regime suggest that these ants are shift workers in their respective colonies, and they probably use their circadian clocks for this purpose. Circadian plasticity thus appears to be a general strategy of the media workers of the ant species C. compressus to cope with the challenges arising due to their roles in the colony constantly exposed to a fluctuating environment.     

Auditory sensitivity and frequency selectivity in greater spear-nosed bats suggest specializations for acoustic communication

We investigated the relationship between auditory sensitivity, frequency selectivity, and the vocal repertoire of greater spear-nosed bats (Phyllostomus hastatus). P. hastatus commonly emit three types of vocalizations: group-specific foraging calls that range from 6 to 11 kHz, low amplitude echolocation calls that sweep from 80 to 40 kHz, and infant isolation calls from 15 to 100 kHz. To determine if hearing in P. hastatus is differentially sensitive or selective to frequencies in these calls, we determined absolute thresholds and masked thresholds using an operant conditioning procedure. Both absolute and masked thresholds were lowest at 15 kHz, which corresponds with the peak energy of isolation calls. Auditory and masked thresholds were higher at sound frequencies used for group-specific foraging calls and echolocation calls. Isolation calls meet the requirements of individual signatures and facilitate parent-offspring recognition. Many bat species produce isolation calls with peak energy between 10 and 25 kHz, which corresponds with the frequency region of highest sensitivity in those species for which audiogram data are available. These findings suggest that selection for accurate offspring recognition exerts a strong influence on the sensory system of P. hastatus and likely on other species of group-living bats.     

Breeding biology and social behaviour of Magellanic Woodpeckers (<Emphasis Type="Italic">Campephilus magellanicus</Emphasis>) in Argentine Patagonia

The Magellanic Woodpecker (Campephilus magellanicus) is a poorly known species endemic of the Austral Temperate Forests of South America, where it is a potential keystone habitat modifier. Here, I summarize data on the social and breeding biology of this woodpecker, based on 22 active nests located from 1998–2002 in forests from northwestern Argentine Patagonia. Woodpeckers normally traveled in pairs or family parties. In late Austral winter, one to three cavities were selected for completion at each territory. Breeding occurred between mid- to late spring and early to mid-summer, and took about 65 days. Monogamous parents shared duties in nest excavation, incubation and young rearing. Egg length (±SD) measured 34.13±0.79 mm and egg breadth 23.91±0.67 mm, and incubation took roughly 20 days. Nestlings were altricial and remained at the nest for about 45 days. Clutch size was one, occasionally two eggs, and one nestling was produced at all successful nests. Young remained with their family group for up to 2 years or more, and were fed by adults, who normally bred every second year. Nest re-use, nest predation and helpers at the nest were not recorded. Holes were placed (±SD) 8.84±3.71 m high and were 32.3±5.32 cm deep. Entrances (±SD) were 8.92±0.46 cm wide and 15.59±2.54 cm high and mostly oval in shape. Peculiarities of the breeding biology and social behaviour of this species are discussed in the light of patterns common to picids, especially Campephilus spp.     

Modulation of the histaminergic system and behaviour by alpha-fluoromethylhistidine in zebrafish

The functional role of histamine (HA) in zebrafish brains was studied. Zebrafish did not display a clear circadian variation in brain HA levels. Loading of zebrafish with l-histidine increased HA concentration in the brain. A single injection of the histidine decarboxylase (HDC) inhibitor, alpha-fluoromethylhistidine (alpha-FMH), gave rise to a rapid reduction in zebrafish brain HA. Low HDC activity in the brain after injections verified the effect of alpha-FMH. A reduction in the number of histaminergic fibres but not neurones and an increased expression of HDC mRNA was evident after alpha-FMH. Automated behavioural analysis after alpha-FMH injection showed no change in swimming activity, but abnormalities were detected in exploratory behaviour examined in a circular tank. No significant behavioural changes were detected after histidine loading. The time spent for performance in the T-maze was significantly increased in the first trial 4 days after alpha-FMH injections, suggesting that lack of HA may impair long-term memory. The rostrodorsal telencephalon, considered to correspond to the mammalian amygdala and hippocampus in zebrafish, is densely innervated by histaminergic fibres. These results suggest that low HA decreases anxiety and/or affects learning and memory in zebrafish, possibly through mechanisms that involve the dorsal forebrain.