Tracing the genetic footprints of vertebrate landing in non-teleost ray-finned fishes

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Nonlinear acoustic complexity in a fish 'two-voice' system

Acoustic signals play essential roles in social communication and show a strong selection for novel morphologies leading to increased call complexity in many taxa. Among vertebrates, repeated innovations in the larynges of frogs and mammals and the syrinx of songbirds have enhanced the spectro-temporal content, and hence the diversity of vocalizations. This acoustic diversification includes nonlinear characteristics that expand frequency profiles beyond the traditional categorization of harmonic and broadband calls. Fishes have remained a notable exception to evidence for such acoustic innovations among vertebrates, despite their being the largest group of living vertebrates that also exhibit widespread evolution of sound production. Here, we combine rigorous acoustic and mathematical analyses with experimental silencing of the vocal motor system to show how a novel swim bladder mechanism in a toadfish enables it to generate calls exhibiting nonlinearities like those found among frogs, birds and mammals, including primates. By showing that fishes have evolved nonlinear acoustic signalling like all other major lineages of vocal vertebrates, these results suggest strong selection pressure favouring this mechanism to enrich the spectro-temporal content and complexity of vocal signals.     

Chemical characterisation,antioxidant and antimicrobial screening for the revaluation of wine supply chain by-products oriented to circular economy

Abstract

Aim of the project was the bioassay guided optimisation of extraction methods applied to wine chain by-product to obtain extracts, fractions and biologically active biomolecules with a possible use in the nutraceutical and cosmeceutical industry. Exhausted red and white grape marc were extracted using water:ethanol 50:50 with ultrasound assisted extraction and Naviglio® technology; and also with supercritical fluid extraction (SFE) and steam-distillation obtaining different phytocomplexes. Each extract was characterised by different molecular category: exhausted red grape marc (VCR) by anthocyanins, exhausted white grape marc (VCB) by flavonoids, and grapeseed (VIN) by proanthocyanins. SFE and steam-distillation, instead, highlighted the presence of fatty acids and their ester in every matrix, but terpenoids were not revealed at level major or equal than 0.1%, except for manoyl oxide in VCR (2.89%). VIN was the most abundant matrix in polyphenols (506.24?±?55.91?mg gallic acid/g dried extract), and it showed the highest antioxidant activity (IC₅₀ of 4.30?μg/mL). Regarding the antimicrobial activity, the hydroalcoholic extracts from VCR, VCB and VIN were tested but no noteworthy activities have been recorded.     

不同时间睡眠干扰所致小鼠的类抑郁样行为

目的研究不同时间睡眠干扰后所致的小鼠类抑郁样行为学表现。方法使用滚筒睡眠干扰仪对小鼠进行不同时间(5、10、15 d)睡眠干扰后,分别对各组动物进行自主活动测试实验、强迫游泳实验和悬尾实验。结果干扰5 d组与对照组比,自主活动总路程、平均速度、运动总时间减少(P<0.05),干扰10 d组与对照组比,自主活动总路程、平均速度、运动总时间减少(P<0.05)。干扰5 d后,小鼠强迫游泳、悬尾实验中各指标与对照组比无差异,干扰10 d组小鼠的游泳不动时间[(143.92±9.48)s]和悬尾不动时间[(127.89±6.33)s]均较对照组小鼠游泳不动时间[(128.50±6.63)s]和悬尾不动时间[(102.64±9.57)s]长(P<0.05),干扰15 d组小鼠的游泳不动时间[(143.08±8.13)s]和悬尾不动时间[(119.10±10.43)s]均较对照组小鼠游泳不动时间[(113.00±7.28)s]和悬尾不动时间[(89.55±9.07)s]长(P<0.05)。干扰5 d组、10 d组、15 d组与对照组比,体重均降低(P<0.05)。结论滚筒法睡眠干扰10、15 d可引起小鼠的类抑郁样行为学表现。     

The selective glucocorticoid receptor antagonist CORT 108297 decreases neuroendocrine stress responses and immobility in the forced swim test

Pre-clinical and clinical studies have employed treatment with glucocorticoid receptor (GR) antagonists in an attempt to limit the deleterious behavioral and physiological effects of excess glucocorticoids. Here, we examined the effects of GR antagonists on neuroendocrine and behavioral stress responses, using two compounds: mifepristone, a GR antagonist that is also a progesterone receptor antagonist, and CORT 108297, a specific GR antagonist lacking anti-progestin activity. Given its well-documented impact on neuroendocrine and behavioral stress responses, imipramine (tricyclic antidepressant) served as a positive control. Male rats were treated for five days with mifepristone (10 mg/kg), CORT 108297 (30 mg/kg and 60 mg/kg), imipramine (10 mg/kg) or vehicle and exposed to forced swim test (FST) or restraint stress. Relative to vehicle, imipramine potently suppressed adrenocorticotropin hormone (ACTH) responses to FST and restraint exposure. Imipramine also decreased immobility in the FST, consistent with antidepressant actions. Both doses of CORT 108297 potently suppressed peak corticosterone responses to FST and restraint stress. However, only the higher dose of CORT 108297 (60 mg/kg) significantly decreased immobility in the FST. In contrast, mifepristone induced protracted secretion of corticosterone in response to both stressors, and modestly decreased immobility in the FST. Taken together, the data indicate distinct effects of each compound on neuroendocrine stress responses and also highlight dissociation between corticosterone responses and immobility in the FST. Within the context of the present study, our data suggest that CORT 108297 may be an attractive alternative for mitigating neuroendocrine and behavioral states associated with excess glucocorticoid secretion.     

The critical swimming velocity of diploid and triploid brook trout

No significant difference was found in the critical swimming velocity of diploid and triploid brook trout Salvelinus fontinalis , suggesting that the triploid state is not associated with a reduced aerobic capacity.     

Impact of different groups of swimmers on dolphins in swim-with-the-dolphin programs in two settings

Abstract

In recent years, dolphin-assisted therapy has become very popular, and an increasing number of facilities worldwide are offering therapy programs that incorporate dolphins. We observed 83 sessions with five dolphins at “Dolphins Plus,” USA, and 37 sessions with 13 dolphins at “Dolphin Reef.” Israel, during unstructured swim-with-the-dolphin programs. Both facilities are fenced sea pens with ocean water. Our detailed observations focused on contact and distance behaviors between dolphins and amongst dolphins with different groups of human swimmers: adults, children and children with mental and physical disabilities at “Dolphins Plus,” and adults only at “Dolphin Reef.” The dolphins at “Dolphins Plus” showed some signs of stress such as avoidance, speed increase, higher metabolism and intensification of a subgroup. These signs were most evident when the dolphins were with adult swimmers. In contrast, the dolphins at “Dolphin Reef” seemed to be attracted to adult swimmers. We will discuss these opposing findings with reference to the different housing conditions. Our results indicate that limited space results in a reduction of the dolphins' attraction for swimmers.     

Global Down-Regulation of Gene Expression in the Brain Using RNA Interference,with Emphasis on Monoamine Transporters and GPCRs: Implications for Target Characterization in Psychiatric and Neurological Disorders

RNA interference (RNAi) is a natural mechanism for regulating gene expression, which exists in plants, invertebrates, and mammals. We investigated whether non-viral infusion of short interfering RNA (siRNA) by the intracerebroventricular route would enable a sequence-specific gene knockdown in the mouse brain and whether the knockdown translates into disease-relevant behavioral changes. Initially, we targeted enhanced green fluorescent protein (EGFP) in mice overexpressing EGFP. A selective knockdown of both EGFP protein and mRNA was observed throughout the brain, with lesser down-regulation in regions distal to the infusion site. We then targeted endogenous genes, encoding the dopamine (DAT) and serotonin transporters (SERT). DAT-siRNA infusion in adult mice produced a significant down-regulation of DAT mRNA and protein and elicited hyperlocomotion similar, but delayed, to that produced on infusion of GBR-12909, a potent and selective DAT inhibitor. Similarly, SERT-siRNA infusion resulted in significant knockdown of SERT mRNA and protein and elicited reduced immobility in the forced swim test similar to that obtained on infusion of citalopram, a very selective and potent SSRI. Application of this non-viral RNAi approach may accelerate target validation for neuropsychiatric disorders that involve a complex interplay of gene(s) from various brain regions.     

Relationships between metabolic rate, muscle electromyograms and swim performance of adult chinook salmon

Oxygen consumption rates of adult spring chinook salmon Oncorhynchus tshawytscha increased with swim speed and, depending on temperature and fish mass, ranged from 609 mg O₂ h^?1 at 30 cm s^?1 (c. 0·5 BL s^?1) to 3347 mg O₂ h^?1 at 170 cm s^?1 (c. 2·3 BL s^?1). Corrected for fish mass, these values ranged from 122 to 670 mg O₂ kg^?1 h^?1, and were similar to other Oncorhynchus species. At all temperatures (8, 12·5 and 17° C), maximum oxygen consumption values levelled off and slightly declined with increasing swim speed >170 cm s^?1, and a third‐order polynomial regression model fitted the data best. The upper critical swim speed (U_crit) of fish tested at two laboratories averaged 155 cm s^?1 (2·1 BL s^?1), but U_crit of fish tested at the Pacific Northwest National Laboratory were significantly higher (mean 165 cm s^?1) than those from fish tested at the Columbia River Research Laboratory (mean 140 cm s^?1). Swim trials using fish that had electromyogram (EMG) transmitters implanted in them suggested that at a swim speed of c. 135 cm s^?1, red muscle EMG pulse rates slowed and white muscle EMG pulse rates increased. Although there was significant variation between individual fish, this swim speed was c. 80% of the U_crit for the fish used in the EMG trials (mean U_crit 168·2 cm s^?1). Bioenergetic modelling of the upstream migration of adult chinook salmon should consider incorporating an anaerobic fraction of the energy budget when swim speeds are ≥80% of the U_crit.