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The function of the hippocampus depends on the process of adult hippocampal neurogenesis which underpins the exceptional neural plasticity of this structure, and is also frequently affected in CNS pathologies. Thus, manipulation of this process represents an important therapeutic goal. To identify potential strategies, organotypic adult brain slices are emerging as a valuable tool. Over the recent years, this methodology has been refined and here we present a combined protocol that brings together these refinements to enable long-term culture of adult hippocampal slices. We employ a sectioning technique that retains essential afferent inputs onto the hippocampus as well as serum-free culture conditions, so allowing an extended culture period. To sustain the neurogenic potential in the slices, we utilize the gliogenesis-inhibitor Indomethacin. Using EdU retention analysis enables us to assess the effects of pharmacological intervention on neurogenesis. With these improvements, we have established an easy and reliable method to study the effects of small molecules/drugs on proliferation and neuron formation ex vivo which will facilitate future discovery driven drug screenings.

Background: Numerous researches have been done on the permanent maxillary first molars for the presence of an extra canal, especially the mesiobuccal roots for the presence of MB2 canals. Cone beam computed tomography (CBCT) has been used recently in the detection of these canals. However, literature discussing the efficacy and reliability of CBCT in the detection of these canals is scanty. Aims: This study aims to evaluate the efficacy of CBCT as a preoperative diagnostic aid in locating the second mesiobuccal canal in maxillary first molars. Methods: Selected sixty extracted maxillary first molars were placed in the skull base, and CBCT scans were done for evaluating the presence of MB2 canals in the mesiobuccal root. Sectioning of the roots at 3, 5, and 7 mm from the tip was performed and further examined under the microscope for the presence of the MB2 canals. Evaluations were done by two evaluators independently. Results of evaluations were statistically analyzed. Statistical analysis used were standard normal deviation (Z value), interrater reliability (Chronbach's alpha-), P value and receiver operating curve(ROC). Results and Conclusions: Detection rates of MB2 using both the methods did not show any significant difference (P > 0.05). CBCT was found to be a reliable tool for the detection of MB2 canal in maxillary first molar teeth when compared to gold standard sectioning technique.

We attempted to settle the potential problems of bias caused by too soft earplugs and poor formation of the growth layers in age readings of common minke whales. Thus, we examined the feasibility of a new technique of incorporating gelatin in order to collect earplugs for age assessment. Frozen sectioning and histology of the earplug core were also used as methods to improve age estimation. Earplugs were collected by filling the space in the external auditory meatus with gelatin, hardening the gelatin, earplug and its fragments, by spraying with cooling gas, and removing the earplug embedded in gelatin. In 174 trials with common minke whales in the Western North Pacific of coastal waters of Japan in 2007–2009, it was revealed that embedding earplugs with gelatin minimized breakage and protected the neonatal line (NL). This method was particularly effective in younger animals. As a result, the readability was improved. We also examined the histological sections, which were sliced using the Kawamoto specialized frozen sectioning technique, and stained them separately with toluidine blue, haematoxylin and eosin, Sudan III, Sudan VII, and alizarin red S to display a clearer core surface image of the growth layers. The histological sections stained with alizarin red S provided the clearest images, in which we could easily identify both dark and pale laminations. This suggested a close relationship with the seasonal changes in calcium intake from feeding. Earlier age estimation methods focused on fat content in the growth layers; however, we found potential for an improvement in the readability of unclear growth layers when focusing on calcium.

International audience; Surface degradation and cracking of dense hydroxyapatite were evaluated through Vickers micro indentation using indentation loads ranged from 25 gf to 2000 gf. Crack lengths, imprint diameters and the number of lateral cracks and chips were measured using SEM. The crack length-indentation load data were analyzed with regard to the specific relations of Palmqvist and fully developed radial cracks. Crack type transition load from Palmqvist to median crack was experimentally assessed through serial sectioning technique. The analytical estimated transition load, based on the theoretical relation of the indentation load and crack lengths showed a good agreement with one obtained from experimental itinerary. Palmqvist and median cracks were identified in low and medium indentation loads, respectively. High indentation load could also lead to the formation of lateral cracks and chips. The tendency for lateral cracking was evaluated taking into account the number of lateral cracks and chips. The chips were found to be appeared just after test in higher indentation load, whereas in medium loads they could be detectable only after several weeks.