Experimenter sex modulates mouse biobehavioural and pharmacological responses

Differential rodent responses to the sex of human experimenters could have far reaching consequences in preclinical studies. Here, we show that the sex of human experimenters affects mouse behaviours and responses to the rapid-acting antidepressant ketamine and its bioactive metabolite (2R,6R)-hydroxynorketamine. We found that mice manifest aversion to human male odours, preference to female odours, and increased susceptibility to stress when handled by male experimenters. This male induced aversion and stress susceptibility is mediated by the activation of brain corticotropin-releasing factor (CRF) neurons projecting from the entorhinal cortrex to hippocampal area CA1. We further establish that exposure to male scent prior to ketamine administration activates CRF neurons projecting from the entorhinal cortex to hippocampus, and that CRF is necessary and sufficient for the in vivo and in vitro actions of ketamine. Further understanding of the specific and quantitative contributions of the sex of human experimenters to different experimental outcomes in rodents may lead not only to reduced heterogeneity between studies, but also increased capability to uncover novel biological mechanisms.

Estradiol mediates stress-susceptibility in the male brain

In susceptible populations, stress is a major risk factor for the development of mental disorders, including depression. Estradiol, often considered a female hormone, is distributed in the male brain via aromatization of testosterone. The role of estrogen receptors (ERs) in male stress susceptibility and depression is not well understood. We found that absence of ERβ is associated with susceptibility to stress in male mice and that activity of ERβ-projecting neurons from the basolateral amygdala to nucleus accumbens is reduced in hypogonadal mice subjected to stress, while activation of this circuit reverses stress-induced maladaptive behaviors. We identified that absence of estradiol, but not testosterone per se, underlies stress susceptibility and that brain-selective delivery of estradiol prevents the development of depression-related behaviors. Our findings provide evidence for an estrogen-based mechanism underlying stress susceptibility and offer an unexpected therapeutic strategy for treating depression in males.

Drought Tolerant Near Isogenic Lines of Pusa 44 Pyramided With qDTY2.1 and qDTY3.1, Show Accelerated Recovery Response in a High Throughput Phenomics Based Phenotyping

Reproductive stage drought stress (RSDS) is a major challenge in rice production worldwide. Cultivar development with drought tolerance has been slow due to the lack of precise high throughput phenotyping tools to quantify drought stress-induced effects. Most of the available techniques are based on destructive sampling and do not assess the progress of the plant’s response to drought. In this study, we have used state-of-the-art image-based phenotyping in a phenomics platform that offers a controlled environment, non-invasive phenotyping, high accuracy, speed, and continuity. In rice, several quantitative trait loci (QTLs) which govern grain yield under drought determine RSDS tolerance. Among these, qDTY2.1 and qDTY3.1 were used for marker-assisted breeding. A set of 35 near-isogenic lines (NILs), introgressed with these QTLs in the popular variety, Pusa 44 were used to assess the efficiency of image-based phenotyping for RSDS tolerance. NILs offered the most reliable contrast since they differed from Pusa 44 only for the QTLs. Four traits, namely, the projected shoot area (PSA), water use (WU), transpiration rate (TR), and red-green-blue (RGB) and near-infrared (NIR) values were used. Differential temporal responses could be seen under drought, but not under unstressed conditions. NILs showed significant level of RSDS tolerance as compared to Pusa 44. Among the traits, PSA showed strong association with yield (80%) as well as with two drought tolerances indices, stress susceptibility index (SSI) and tolerance index (TOL), establishing its ability in identifying the best drought tolerant NILs. The results revealed that the introgression of QTLs helped minimize the mean WU per unit of biomass per day, suggesting the potential role of these QTLs in improving WU-efficiency (WUE). We identified 11 NILs based on phenomics traits as well as performance under imposed drought in the field. The study emphasizes the use of phenomics traits as selection criteria for RSDS tolerance at an early stage, and is the first report of using phenomics parameters in RSDS selection in rice.

Molecular phylogeny of heritable symbionts and microbiota diversity analysis in phlebotominae sand flies and Culex nigripalpus from Colombia

Background Secondary symbionts of insects include a range of bacteria and fungi that perform various functional roles on their hosts, such as fitness, tolerance to heat stress, susceptibility to insecticides, reproduction. These endosymbionts could have the potential to shape microbial communites and high potential to develop strategies for mosquito-borne disease control. Methodology/Principal findings The relative frequency and molecular phylogeny of Wolbachia, Microsporidia and Cardinium were determined of phlebotomine sand flies and mosquitoes in two regions from Colombia. Illumina Miseq using the 16S rRNA gene as a biomarker was conducted to examine the microbiota. Different percentages of natural infection by Wolbachia, Cardinium, and Microsporidia in phlebotomines and mosquitoes were detected. Phylogenetic analysis of Wolbachia shows putative new strains of Lutzomyia gomezi (wLgom), Brumptomyia hamata (wBrham), and a putative new group associated with Culex nigripalpus (Cnig) from the Andean region, located in Supergroup A and Supergroup B, respectively. The sequences of Microsporidia were obtained of Pi. pia and Cx. nigripalpus, which are located on phylogeny in the IV clade (terrestrial origin). The Cardinium of Tr. triramula and Ps. shannoni were located in group C next to Culicoides sequences while Cardinium of Mi. cayennensis formed two putative new subgroups of Cardinium in group A. In total were obtained 550 bacterial amplicon sequence variants (ASVs) and 189 taxa to the genus level. The microbiota profiles of Sand flies and mosquitoes showed mainly at the phylum level to Proteobacteria (67.6%), Firmicutes (17.9%) and Actinobacteria (7.4%). High percentages of relative abundance for Wolbachia (30%-83%) in Lu. gomezi, Ev. dubitans, Mi. micropyga, Br. hamata, and Cx. nigripalpus were found. ASVs assigned as Microsporidia were found in greater abundance in Pi. pia (23%) and Cx. nigripalpus (11%). An important finding is the detection of Rickettsia in Pi. pia (58,8%) and Bartonella sp. in Cx. nigripalpus. Conclusions/Significance We found that Wolbachia infection significantly decreased the alpha diversity and negatively impacts the number of taxa on sand flies and Culex nigripalpus. The Principal Coordinate Analysis (PCoA) is consistent, which showed statistically significant differences (PERMANOVA, F = 2.4744; R2 = 0.18363; p-value = 0.007) between the microbiota of sand flies and mosquitoes depending on its origin, host and possibly for the abundance of some endosymbionts (Wolbachia, Rickettsia).

Activation of Npas1-neurons in the Ventral Pallidum Mediates Stress Susceptibility

Background: Altered activity of the ventral pallidum (VP) underlies disrupted motivation after stress exposure. The VP is a very heterogeneous structure comprised of many different neuron types with distinct electrophysiological properties and projections. Neuronal PAS 1-positive (Npas1+) VP neurons are thought to send projections to brain regions critical for stress response. In this study, we evaluated how activity of VP Npas1+ neurons affect emotional behaviors and responses to social stress. Methods: We used a chemogenetic approach to manipulate VP Npas1+ neurons during social defeat stress (SDS) and behavioral tasks related to anxiety and motivation in Npas1-Cre mice. We employed a similar approach in females using the chronic witness defeat stress (CWDS). Finally, to characterize VP Npas1+ neuron circuitry and molecular identity we evaluated the projection targets of the VP Npas1+ neurons and performed RNA-seq on ribosome-associated mRNA from VP Npas1+ neurons. Results: Chemogenetic activation of VP Npas1+ neurons increased susceptibility to a subthreshold (S)SDS and anxiety-like behavior in the elevated plus maze and open field. Inhibition of VP Npas1+ neurons enhanced resilience to chronic (C)SDS and CWDS. We identified VP Npas1+ projections to the nucleus accumbens (NAc), ventral tegmental area (VTA), medial and lateral habenula (LHb), lateral hypothalamus (LH), thalamus, medial and lateral septum, and periaqueductal gray area. VP Npas1+ neurons displayed distinct transcriptomes representing distinct biological processes. Conclusions: Activity, of VP Npas1+ neurons, modulates susceptibility to social stressors and anxiety-like behavior. These outcomes could be related to their projections to brain regions that modulate reward and aversion.

Working memory training efficacy in COPD: the randomised double-blind placebo-controlled Cogtrain trial

BackgroundCognitive impairment (CI) is highly prevalent in chronic obstructive pulmonary disease (COPD) and is associated with a sedentary lifestyle, unhealthy diet and increased cognitive stress susceptibility. Enhancement of cognitive performance by working memory training (WMT) may reverse these effects. Therefore, this study aimed to investigate the efficacy of WMT in COPD on cognitive performance, healthy lifestyle behaviours and cognitive stress susceptibility.MethodsThe double-blind randomised, placebo-controlled Cogtrain trial consisted of a 12-week training phase comprising 30 active or sham WMT sessions, followed by a second 12-week maintenance phase with 12 sessions. Measurements took place at baseline and after the first and second phases. The primary outcome was cognitive performance. Secondary outcomes were the recall of prespecified healthy lifestyle goals, physical capacity and activity, dietary quality, and cognitive stress susceptibility. Motivation towards exercising and healthy eating and psychological wellbeing were exploratory outcomes.ResultsSixty-four patients with moderate COPD (45% male, aged 66.2±7.2 years, median FEV1 60.6% predicted) were randomised. WMT significantly increased patients’ performance on the trained tasks in the first phase, which remained stable in the second phase. Of the 17 cognitive outcome measures only one measure of memory improved after the first phase and one measure of reaction time after the second phase. This intervention did not influence physical capacity and activity, recall of prespecified healthy lifestyle goals, psychological wellbeing, or cognitive stress susceptibility.ConclusionWMT improved performance on the trained tasks but not overall cognitive performance, healthy lifestyle behaviours or cognitive stress susceptibility in patients with COPD.

Artificial Reproductive Technology (ART) Applied to Female Cervids Adapted from Domestic Ruminants

There are about 150 Cervidae species on the IUCN Red List of Threatened Species. Only a small part is counted among farm animals, and most of them are free roaming. The universality and large numbers of representatives of cervids such as red deer (Cervus elaphus) and roe deer (Capreolus capreolus) may predispose these species to be used as models for research on reintroduction or assisted reproduction of deer at risk of extinction. We outlined the historical fluctuation of cervids in Europe and the process of domestication, which led to breeding management. Consequently, the reproductive techniques used in domestic ruminants were adapted for use in female deer which we reviewed based on our results and other available results. We focused on stress susceptibility in cervids depending on habitat and antropopression and proposed copeptin as a novel diagnostic parameter suitable for stress determination. Some reproductive biotechniques have been adopted for female cervids with satisfactory results, e.g., in vitro fertilization, while others still require methodological refinement, e.g., cryopreservation of oocytes and embryos.

7 Behavioral Indicators of Post-weaning Stress Susceptibility in Cross-fostered Pigs

Cross-fostering is a common swine husbandry practice; however, little research has focused on the effects of foster stress on piglets post-weaning. This study evaluated the effect of cross-fostering on behavioral indicators of post-weaning stress susceptibility. Litters (n = 40) were allocated to 1 of 2 treatments: control (CON) and foster. Three piglets (FOS) from each CON litter were randomly selected and moved to a foster litter 12–24 h post-farrowing, where they were nursed along resident (RES) piglets until weaning (approximately 18 d of age). At 21- and 28-d post-weaning, a male and female piglet from each treatment (FOS, RES, CON) underwent 1 of 2 behavior tests: social isolation and social confrontation. Both tests were conducted in an isolated 1.22 × 1.22 m novel pen. For social isolation, escape attempts, movement between floor quadrants (i.e. locomotion), defecation, and urination events were counted. For social confrontation, the latency to first aggressive interaction and the number of aggressive interactions were quantified. All data were analyzed using the GLIMMIX procedure in SAS. The CON piglets moved between quadrants more frequently than RES piglets (P = 0.02), while FOS piglets moved between quadrants intermediate to (but not different from) CON and RES piglets (P = 0.44 and 0.12, respectively). Females moved between quadrants more frequently than males (P < 0.0001). The latency to first aggressive interaction was shorter in FOS piglets compared to CON piglets (P = 0.048). There was a treatment by sex interaction (P < 0.01) for number of aggressive interactions, with CON and RES females having more aggressive interactions than their male counterparts (P = 0.04 for both) while FOS females had fewer aggressive interactions than FOS males (P = 0.007). No additional differences were detected (all P > 0.05). Overall, these results provide little evidence that FOS piglets exhibit an increase in behavioral stress susceptibility post-weaning. However, future work should expand upon and clarify the social confrontation findings.