Protective and vulnerability personality traits associated with PTSD diagnosis after preterm delivery.

Giving birth prematurely is a traumatic event that has many consequences for the mother but also for her baby and their family. Studies have shown that about a quarter of these mothers will suffer from post-traumatic stress disorder (PTSD) as a result. This study aims to identify internal personality factors associated with the development of PTSD in mothers who gave birth before 33 weeks. The results revealed significant correlations between two personality dimensions (neuroticism and extraversion) and the likeliness of developing PTSD in mothers who gave birth prematurely. Neuroticism is positively liked with the disorder while extraversion is negatively correlated with it. Studies should now focus on early detection of PTSD and better interventions for these mothers.

Force sensor in simulated skin and neural model mimic tactile SAI afferent spiking response to ramp and hold stimuli.

BACKGROUND: The next generation of prosthetic limbs will restore sensory feedback to the nervous system by mimicking how skin mechanoreceptors, innervated by afferents, produce trains of action potentials in response to compressive stimuli. Prior work has addressed building sensors within skin substitutes for robotics, modeling skin mechanics and neural dynamics of mechanotransduction, and predicting response timing of action potentials for vibration. The effort here is unique because it accounts for skin elasticity by measuring force within simulated skin, utilizes few free model parameters for parsimony, and separates parameter fitting and model validation. Additionally, the ramp-and-hold, sustained stimuli used in this work capture the essential features of the everyday task of contacting and holding an object. METHODS: This systems integration effort computationally replicates the neural firing behavior for a slowly adapting type I (SAI) afferent in its temporally varying response to both intensity and rate of indentation force by combining a physical force sensor, housed in a skin-like substrate, with a mathematical model of neuronal spiking, the leaky integrate-and-fire. Comparison experiments were then conducted using ramp-and-hold stimuli on both the spiking-sensor model and mouse SAI afferents. The model parameters were iteratively fit against recorded SAI interspike intervals (ISI) before validating the model to assess its performance. RESULTS: Model-predicted spike firing compares favorably with that observed for single SAI afferents. As indentation magnitude increases (1.2, 1.3, to 1.4 mm), mean ISI decreases from 98.81 ± 24.73, 54.52 ± 6.94, to 41.11 ± 6.11 ms. Moreover, as rate of ramp-up increases, ISI during ramp-up decreases from 21.85 ± 5.33, 19.98 ± 3.10, to 15.42 ± 2.41 ms. Considering first spikes, the predicted latencies exhibited a decreasing trend as stimulus rate increased, as is observed in afferent recordings. Finally, the SAI afferent's characteristic response of producing irregular ISIs is shown to be controllable via manipulating the output filtering from the sensor or adding stochastic noise. CONCLUSIONS: This integrated engineering approach extends prior works focused upon neural dynamics and vibration. Future efforts will perfect measures of performance, such as first spike latency and irregular ISIs, and link the generation of characteristic features within trains of action potentials with current pulse waveforms that stimulate single action potentials at the peripheral afferent.

Landscape and Local Drivers Affecting Flying Insects along Fennel Crops (Foeniculum vulgare, Apiaceae) and Implications for Its Yield.

Agricultural landscapes are increasingly characterized by intensification and habitat losses. Landscape composition and configuration are known to mediate insect abundance and richness. In the context of global insect decline, and despite 75% of crops being dependent on insects, there is still a gap of knowledge about the link between pollinators and aromatic crops. Fennel (Foeniculum vulgare) is an aromatic plant cultivated in the South of France for its essential oil, which is of great economic interest. Using pan-traps, we investigated the influence of the surrounding habitats at landscape scale (semi-natural habitat proportion and vicinity, landscape configuration) and local scale agricultural practices (insecticides and patch size) on fennel-flower-visitor abundance and richness, and their subsequent impact on fennel essential oil yield. We found that fennel may to be a generalist plant species. We did not find any effect of intense local management practices on insect abundance and richness. Landscape configuration and proximity to semi-natural habitat were the main drivers of flying insect family richness. This richness positively influenced fennel essential oil yield. Maintaining a complex configuration of patches at the landscape scale is important to sustain insect diversity and crop yield.

Skin relaxation predicts neural firing rate adaptation in SAI touch receptors.

In response to ramp-and-hold indentation, the slowly-adapting type I (SAI) afferent exhibits an exponential decrease in its firing frequency during the hold phase. Such adaptation may be tied to skin relaxation but is neither well understood nor has it been quantitatively modeled. The specific hypothesis of this work is that skin relaxation is a primary contributor to observed changes in firing rate. Double exponential functions were fit to 21 responses from a mouse SAI afferent for both instantaneous firing rate and indenter tip force over time. The model was then generalized by using a linear transformation between fit parameters for force and firing rate data, allowing prediction of firing rates from force. The results show that the generalized model matches the recorded firing rate (R(2) = 0.65) equally well as fitting a doubleexponential function directly to firing rate (R(2) = 0.67) for a second dataset. When the procedure was repeated with two D-hair fibers, the generalized model matched the recorded firing rate (R(2) = 0.47) much more poorly compared to the fitted double-exponential function (R(2) = 0.89). Thus, firing rate adaptation in SAI responses can be predicted by skin relaxation, whereas this factor alone did not adequately describe adaptation in the D-hair.

Axl-/- mice have delayed recovery and prolonged axonal damage following cuprizone toxicity.

Activation of the receptor tyrosine kinase Axl recruits signaling molecules that regulate cell growth and survival. To evaluate Axl's role in brain during cuprizone toxicity, mice were fed cuprizone and evaluated at 3-, 4-, and 6-week cuprizone treatment and 3- and 5-week post-cuprizone withdrawal. At 4-week cuprizone treatment, the corpora callosa of wildtype (WT) mice had robust Oil Red O+ staining indicative of ongoing phagocytosis. Axl-/- mice had minimal Oil Red O+ staining, fewer microglia, and significantly more TUNEL+/ASPA+ mature oligodendrocytes than the WT. At 6-week cuprizone treatment, there was significantly more Oil Red O+ staining in the Axl-/- corpora callosa than in the WT indicating a lag in the clearance of cellular and myelin debris. Relative to WT mice, there were fewer mature oligodendrocytes and significantly more SMI-32+ axons at 3-week post-cuprizone withdrawal, indicative of axonal damage in the Axl-/- corpora callosa. Electron microscopy determined that at 3-week post-cuprizone withdrawal the number of dystrophic axons and axons containing autophagosome-like vacuoles/mouse was increased in the Axl-/- mice relative to the WT mice. In Axl-/- corpora callosa, 5-week post-cuprizone withdrawal, the number of mature oligodendrocytes was comparable to the WT mice, but axons in the Axl-/- mice were SMI-32+, suggesting that Axl-/- mice have delayed clearance of apoptotic oligodendrocytes and myelin debris resulting in prolonged axonal damage and recovery from cuprizone toxicity.