Cellular ultrastructures for signal integration are unknown in any nervous system. The ellipsoid body (EB) of the Drosophila brain is thought to control locomotion upon integration of various modalities of sensory signals with the animal internal status. However, the expected excitatory and inhibitory input convergence that virtually all brain centres exhibit is not yet described in the EB. Based on the EB expression domains of genetic constructs from the choline acetyl transferase (Cha), glutamic acid decarboxylase (GAD) and tyrosine hydroxylase (TH) genes, we identified a new set of neurons with the characteristic ring-shaped morphology (R neurons) which are presumably cholinergic, in addition to the existing GABA-expressing neurons. The R1 morphological subtype is represented in the Cha- and TH-expressing classes. In addition, using transmission electron microscopy, we identified a novel type of synapse in the EB, which exhibits the precise array of two independent active zones over the same postsynaptic dendritic domain, that we named 'agora'. This array is compatible with a coincidence detector role, and represents ~8% of all EB synapses in Drosophila. Presumably excitatory R neurons contribute to coincident synapses. Functional silencing of EB neurons by driving genetically tetanus toxin expression either reduces walking speed or alters movement orientation depending on the targeted R neuron subset, thus revealing functional specialisations in the EB for locomotion control.

Synapse loss correlates with cognitive decline in aging and most neurological pathologies. Sensory perception changes often represent subtle dysfunctions that precede the onset of a neurodegenerative disease. However, a cause-effect relationship between synapse loss and sensory perception deficits is difficult to prove and quantify due to functional and structural adaptation of neural systems. Here we modified a PI3K/AKT/GSK3 signaling pathway to reduce the number of synapses-without affecting the number of cells-in five subsets of local interneurons of the Drosophila olfactory glomeruli and measured the behavioral effects on olfactory perception. The neuron subsets were chosen under the criteria of GABA or ChAT expression. The reduction of one subset of synapses, mostly inhibitory, converted the responses to all odorants and concentrations tested as repulsive, while the reduction of another subset, mostly excitatory, led to a shift toward attraction. However, the simultaneous reduction of both synapse subsets restored normal perception. One group of local interneurons proved unaffected by the induced synapse loss in the perception of some odorants, indicating a functional specialization of these cells. Using genetic tools for space and temporal control of synapse number decrease, we show that the perception effects are specific to the local interneurons, rather than the mushroom bodies, and are not based on major structural changes elicited during development. These findings demonstrate that synapse loss cause sensory perception changes and suggest that normal perception is based on a balance between excitation and inhibition.

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Sex differences in occupational and leisure time ultraviolet exposure, clothing (including shoes), hairstyle, and side and photo exposure in cars could explain these results. General preventive messages could be completed by sex-specific advice for melanoma prevention.

The aim of this study was to use high-resolution micro-CT to evaluate the effects of three Ni-Ti rotary endodontic instruments, Mtwo® (VDW, München, Germany), ProTaper® (Dentsply-Maillefer, Ballaigues, Switzerland) and Revo-S™ (MicroMega, Besançon, France), on canal transportation and centring ratio. Fifty-four mesial roots of extracted mandibular molars with an angle of curvature of 25-35° were randomly divided into three groups of eighteen. Each group was instrumented with a previously unused Ni-Ti rotary system. The final instruments used were #30/0.05 taper (Mtwo®), F3 #30/0.09 apical taper (ProTaper®) and AS30 #30/0.06 taper (Revo-S™). Teeth were scanned before and after instrumentation using micro-computed tomography with a spatial resolution of 20 μm to measure volume and shaping changes. All images were filtered to improve signal-to-noise ratio. To determine the perimeter of roots and canals exactly, images were segmented in each slice with an edge detection process. Canal transportation and centring ratio were evaluated at 1, 3, 5 and 7 mm from the end of each root. The method developed by Gambill et al. was chosen. ANOVA was conducted with the significance threshold set at p < 0.05. No statistically significant differences were found among the three groups in terms of canal transportation or centring ratio at any level. These systems give similar results with regard to the tested shaping parameters. Under the tested conditions and within the limitations of this study, these systems were able to produce centred preparations of curved canals with minimal transportation.

Aim: To evaluate the impact of a preclinical laboratory session using 3D printed teeth on dental student stress, anxiety, confidence and knowledge when treating deep caries and pulp exposure. Methodology:This was a two-centre controlled study, with randomized distribution of students into two groups: a vital pulp treatment (VPT) lecture-only (control) group and a VPT-lecture combined with a VPT-laboratory (experimental) group. In both universities, preclinical students with endodontic or operative dentistry laboratory sessions could participate. All students were invited to the lecture. Two weeks later (timepoint-T1), both groups completed validated and bespoke questionnaires and scales to evaluate their stress (Stress-VAS), anxiety (STAI Trait [T] and State [S]), self-confidence and knowledge. Thereafter, only the experimental group attended the hands-on laboratory session demonstrating the techniques of selective caries removal and partial pulpotomy on a commercial 3D-printed tooth. Two weeks later (timepoint-T2), the participants from both groups repopulated the same questionnaires and VAS. The control group had the laboratory session after the completion of the study. The statistical analysis was performed with Statistica® (significance p = .05). The homogeneity between the two samples was checked by Khi 2 and Student tests. Stress-VAS, STAI-S, confidence and knowledge scores were compared within each group, and between the two groups, at T1 and T2, with a repeated measures anova test (+/−Tukey post-hoc test). Results:The groups comprised 54 students each, with no statistical difference between the groups regarding demographic, academic data and STAI-T score. The two groups had no significant difference of Stress-VAS, STAI-S, confidence and knowledge scores at T1 while they presented a significant difference in stress, anxiety and confidence scores at T2, but with no significant difference in knowledge score.However, knowledge score, as other parameters, improved significantly between T1 and T2 in the experimental group.

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