Kenneyhalberg9551
We look beyond traditional structural imaging used routinely in clinical care, to include ultrahigh field MRI (7T MRI), magnetoencephalography and PET with novel ligands. We illustrate their potential as safe, robust and sufficiently scalable to be viable for experimental medicine studies and clinical trials. They are especially informative when combined in multimodal studies, with model-based analyses to test precisely defined hypotheses.Resting-state fMRI (rsfMRI) reveals brain dynamics in a task-unconstrained environment as subjects let their minds wander freely. Consequently, resting subjects navigate a rich space of cognitive and perceptual states (i.e., ongoing experience). How this ongoing experience shapes rsfMRI summary metrics (e.g., functional connectivity) is unknown, yet likely to contribute uniquely to within- and between-subject differences. Here we argue that understanding the role of ongoing experience in rsfMRI requires access to standardized, temporally resolved, scientifically validated first-person descriptions of those experiences. We suggest best practices for obtaining those descriptions via introspective methods appropriately adapted for use in fMRI research. We conclude with a set of guidelines for fusing these two data types to answer pressing questions about the etiology of rsfMRI.The ability to sense the world, process information, and navigate the environment depends on the assembly and continuous function of neural circuits in the brain. Within the past two decades, new technologies have rapidly advanced our understanding of how neural circuits are wired during development and how they are stably maintained, often for years. Electron microscopy reconstructions of model organism connectomes have provided a map of the stereotyped (and variable) connections in the brain; advanced light microscopy techniques have enabled direct observation of the cellular dynamics that underlie circuit construction and maintenance; transcriptomic and proteomic surveys of both developing and mature neurons have provided insights into the molecular and genetic programs governing circuit establishment and maintenance; and advanced genetic techniques have allowed for high-throughput discovery of wiring regulators. These tools have empowered scientists to rapidly generate and test hypotheses about how circuits establish and maintain connectivity. Thus, the set of principles governing circuit formation and maintenance have been expanded. These principles are discussed in this review.Innate defensive responses such as freezing or escape are essential for animal survival. Mice show defensive behaviour to stimuli sweeping overhead, like a bird cruising the sky. Here, we tested this in young male mice and found that mice reduced their defensive freezing after sessions with a stimulus passing overhead repeatedly. This habituation is stimulus specific, as mice freeze again to a novel shape. Habituation occurs regardless of the visual field location of the repeated stimulus. The mice generalized over a range of sizes and shapes, but distinguished objects when they differed in both size and shape. Innate visual defensive responses are thus strongly influenced by previous experience as mice learn to ignore specific stimuli.Animals extract behaviorally relevant signals from 'noisy' environments. Echolocation behavior provides a rich system testbed for investigating signal extraction. When echolocating in acoustically enriched environments, bats show many adaptations that are believed to facilitate signal extraction. Most studies to date focused on describing adaptations in insectivorous bats while frugivorous bats have rarely been tested. Here, we characterize how the frugivorous bat Carollia perspicillata adapts its echolocation behavior in response to acoustic playback. Since bats not only adapt their echolocation calls in response to acoustic interference but also with respect to target distances, we swung bats on a pendulum to control for distance-dependent call changes. Forward swings evoked consistent echolocation behavior similar to approach flights. By comparing the echolocation behavior recorded in the presence and absence of acoustic playback, we could precisely define the influence of the acoustic context on the bats' vocal behavior. Our results show that C. perspicillata decrease the terminal peak frequencies of their calls when echolocating in the presence of acoustic playback. When considering the results at an individual level, it became clear that each bat dynamically adjusts different echolocation parameters across and even within experimental days. Utilizing such dynamics, bats create unique echolocation streams that could facilitate signal extraction in noisy environments.Aquatic hypoxia will become increasingly prevalent in the future as a result of eutrophication combined with climate warming. While short-term warming typically constrains fish hypoxia tolerance, many fishes cope with warming by adjusting physiological traits through thermal acclimation. Yet, little is known about how such adjustments affect tolerance to hypoxia. We examined European perch (Perca fluviatilis) from the Biotest enclosure (23°C, Biotest population), a unique ∼1 km2 ecosystem artificially warmed by cooling water from a nuclear power plant, and an adjacent reference site (16-18°C, reference population). Specifically, we evaluated how acute and chronic warming affect routine oxygen consumption rate (ṀO2,routine) and cardiovascular performance in acute hypoxia, alongside assessment of the thermal acclimation of the aerobic contribution to hypoxia tolerance (critical O2 tension for ṀO2,routine Pcrit) and absolute hypoxia tolerance (O2 tension at loss of equilibrium; PLOE). Chronic adjustments (possibly across lifetime or generations) alleviated energetic costs of warming in Biotest perch by depressing ṀO2,routine and cardiac output, and by increasing blood O2 carrying capacity relative to reference perch acutely warmed to 23°C. These adjustments were associated with improved maintenance of cardiovascular function and ṀO2,routine in hypoxia (i.e. reduced Pcrit). However, while Pcrit was only partially thermally compensated in Biotest perch, they had superior absolute hypoxia tolerance (i.e. lowest PLOE) relative to reference perch irrespective of temperature. We show that European perch can thermally adjust physiological traits to safeguard and even improve hypoxia tolerance during chronic environmental warming. This points to cautious optimism that eurythermal fish species may be resilient to the imposition of impaired hypoxia tolerance with climate warming.An exceptional case of parallel evolution between lizards and eutherian mammals occurs in the evolution of viviparity. In the lizard genus Mabuya, viviparity provided the environment for the evolution of yolk-reduced eggs and obligate placentotrophy. One major event that favored the evolution of placentation was the reduction of the eggshell. As with all oviparous reptiles, lizard embryos obtain calcium from both the eggshell and egg yolk. Therefore, the loss of the eggshell likely imposes a constraint for the conservation of the egg yolk, which can only be obviated by the evolution of alternative mechanisms for the transport of calcium directly from the mother. The molecular and cellular mechanisms employed to solve these constraints, in a lizard with only a rudimentary eggshell such as Mabuya, are poorly understood. Here, we used RT-qPCR on placental and uterine samples during different stages of gestation in Mabuya, and demonstrate that transcripts of the calcium transporters trpv6, cabp28k, cabp9k and pmca are expressed and gradually increase in abundance through pregnancy stages, reaching their maximum expression when bone mineralization occurs. Furthermore, CABP28K/9K proteins were studied by immunofluorescence, demonstrating expression in specific regions of the mature placenta. Our results indicate that the machinery for calcium transportation in the Mabuya placenta was co-opted from other tissues elsewhere in the vertebrate bodyplan. Thus, the calcium transportation machinery in the placenta of Mabuya evolved in parallel with the mammalian placenta by redeploying the expression of similar calcium transporter genes.Many animal species show aggression to gain mating partners and to protect territories and other resources from competitors. Both male and female fruit flies of the species Drosophila melanogaster exhibit aggression in same-sex pairings, but the strategies used are sexually dimorphic. We have begun to explore the biological basis for the differing aggression strategies, and the cues promoting one form of aggression over the other. Here, we describe a line of genetically masculinized females that switch between male and female aggression patterns based on the sexual identity of their opponents. When these masculinized females are paired with more aggressive opponents, they increase the amount of male-like aggression they use, but do not alter the level of female aggression. This suggests that male aggression may be more highly responsive to behavioral cues than female aggression. Although the masculinized females of this line show opponent-dependent changes in aggression and courtship behavior, locomotor activity and sleep are unaffected. Thus, the driver line used may specifically masculinize neurons involved in social behavior. A discussion of possible different roles of male and female aggression in fruit flies is included here. These results can serve as precursors to future experiments aimed at elucidating the circuitry and triggering cues underlying sexually dimorphic aggressive behavior.
Women testing positive for
pathogenic variants have high lifetime risks of breast cancer (BC) and ovarian cancer. The effectiveness of risk reducing surgery (RRS) has been demonstrated in numerous previous studies. We evaluated long-term uptake, timing and effectiveness of risk reducing mastectomy (RRM) and bilateral salpingo-oophorectomy (RRSO) in healthy
carriers.
Women were prospectively followed up from positive genetic test (GT) result to censor date. χ² testing compared categorical variables; Cox regression model estimated HRs and 95% CI for BC/ovarian cancer cases associated with RRS, and impact on all-cause mortality; Kaplan-Meier curves estimated cumulative RRS uptake. The annual cancer incidence was estimated by women-years at risk.
In total, 887 women were included in this analysis. Mean follow-up was 6.26 years (range=0.01-24.3; total=4685.4 women-years). RRS was performed in 512 women, 73 before GT. Overall RRM uptake was 57.9% and RRSO uptake was 78.6%. PF-04418948 clinical trial The median time from GT to RRM was 18.4 months, and from GT to RRSO-10.0 months. Annual BC incidence in the study population was 1.28%. Relative BC risk reduction (RRM versus non-RRM) was 94%. link2 Risk reduction of ovarian cancer (RRSO versus non-RRSO) was 100%.
Over a 24-year period, we observed an increasing number of women opting for RRS. We showed that the timing of RRS remains suboptimal, especially in women undergoing RRSO. link3 Both RRM and RRSO showed a significant effect on relevant cancer risk reduction. However, there was no statistically significant RRSO protective effect on BC.
Over a 24-year period, we observed an increasing number of women opting for RRS. We showed that the timing of RRS remains suboptimal, especially in women undergoing RRSO. Both RRM and RRSO showed a significant effect on relevant cancer risk reduction. However, there was no statistically significant RRSO protective effect on BC.