Reliable and reproducible assessment of animal learning and behavior is a central aim of basic and translational neuroscience research. Recent developments in automated operant chamber technology have led to the possibility of universal standard protocols, in addition to increased translational potential, reliability and accuracy. However, the impact of regional and national differences in the supplies of available reinforcers in this system on behavioural performance and inter-laboratory variability is an unknown and at present uncontrolled variable. Therefore, we aimed to identify which constituent(s) of the reward determines reinforcer strength to enable improved standardization of this parameter across laboratories. Male C57BL/6 mice were examined in the touchscreen-based fixed ratio (FR) and progressive ratio (PR) schedules, reinforced with different kinds of milk-based reinforcers to directly compare the incentive values of plain milk (PM, high-calorie: high-fat/low-sugar), strawberry-flavored milk (SM, high-calorie: low-fat/high-sugar), and semi-skimmed low-fat milk (LM, low-calorie: low-fat/low-sugar) on the basis of differences in caloric content, sugar/fat content, and flavor. Use of a higher caloric content reward was effective in increasing operant training acquisition rate. Total trial number completed in FR and breakpoint in PR were higher using the two isocaloric milk products (PM and SM) than the lower caloric LM, with comparable outcomes between PM and SM conditions, suggesting that total caloric content determines reward strength. Analysis of within-session changes in response rate revealed that overall outputs in FR and PR primarily depend on the response rate at the initial phase of a session, which itself was dependent on reinforcer caloric content. Interestingly, the rate of satiation, indicated by decay in response rate within a FR session, was highest when reinforced with SM, suggesting a rapid satiating effect of sugar. The key contribution of reward caloric content to operant performance was confirmed in a multi-laboratory study using the touchscreen 5-choice serial reaction time task (5-CSRTT) reinforced by two isocaloric milk-based liquid rewards with different countries of origin, which yielded consistent performance parameters across sites. Our results indicate that milk-based liquid reinforcer standardization can be facilitated by matching caloric content across laboratories despite regional or national differences in other non-caloric aspects of the reinforcers.Electronic supplementary materialThe online version of this article (doi:10.1186/s13041-017-0312-0) contains supplementary material, which is available to authorized users.

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Objective Conventional methods for organotypic hippocampal tissue slice culture (OHSC) have shown several disadvantages or limitations regarding age of animals used, duration of culture and difficulty using neurodegenerative models. Therefore, we tried to establish OHSC from old 3xTg-Alzheimer’s disease (AD) mice for longer period (over 4 weeks) and to validate utility of this system as a valid platform for translational neuroscience of AD. Methods OHSC was performed with old 3xTg-AD mice (12–14 months), old wild type mice (12–14 months) and young 3xTg-AD mice (2–4 months) using serum-free medium for 4 weeks. Hippocampal structure was evaluated by 4’, 6-diamidino-2-phenylindole (DAPI) intensity and neuronal metabolism was measured by Alamarblue assay. Pathologic characteristics of AD were also investigated; β-amyloid levels by ELISA, amyloid plaque deposition by Thioflavin-S staining, and glial activation by immunohistochemistry. Results Following 4-week culture in serum-free media, hippocampal cells and layers were well preserved in cultured slices from old AD mice as was in those from young AD and old wild type mice. On the contrary, excessive regression of total visible cells was observed in conventional serum-containing medium regardless of genotype of mice. In parallel with this well preserved structure, major pathologic characteristics of AD were also well manifested in hippocampal slices from old AD mice. Conclusion Our findings suggest that long-term OHSC from old 3xTg-AD mouse can serve as a promising ex vivo system for studies on pathophysiology of AD, especially with the minimum number of sacrifice of experimental animals.

this study evaluated age-related trabecular meshwork (tM) height variations in the eyes of adults in different age groups. We hypothesised that a reduction in TM occurs with increasing age. This retrospective, cross-sectional, observational study was conducted at Yonsei University Gangnam Severance Hospital between January 2015 and June 2019. We randomly included 250 eyes of 125 patients who underwent anterior segment optical coherence tomography (AS-OCT). The distance from the scleral spur to Schwalbe's line in patients with normal open anterior chamber angle was measured using AS-OCT. Results were stratified based on patients' age group-≤40, 41-50, 51-60, 61-70, 71-80, and 81-92 years. Thereafter, the results were compared among the age groups. The mean TM height of the patients was 770.929 ± 76.776 μm. TM height was 853.188 ± 94.117 μm in patients aged ≤40 years; it was 815.309 ± 75.723, 798.115 ± 66.040, 770.942 ± 52.774, 726.716 ± 63.979, and 715.968 ± 63.403 μm in patients aged 41-50, 51-60, 61-70, 71-80, and 81-92 years, respectively. The tM height tended to decrease with increasing age (p < 0.001). TM height was significantly shorter in older patients than in younger ones. Therefore, TM height may change with age and may contribute to increased glaucoma risk and prevalence. Scientific RepoRtS | (2020) 10:7115 | https://doi.Mean TM height categorised by age and sex. The mean TM height of the patients in our study was 770.929 ± 76.776 μm. The mean TM height among men was 764.169 ± 85.300 μm and that among women was 776.938 ± 67.120 μm; there was no significant difference between the two groups (P = 0.1911). The mean TM height of patients aged ≤40 years was 853.188 ± 94.117 μm and those of patients aged 41-50, 51-60, 61-70, 71-80, and 81-92 years were 815.309 ± 75.723 μm, 798.115 ± 66.040 μm, 770.942 ± 52.774 μm, 726.716 ± 63.979 μm, and 715.968 ± 63.403 μm, respectively. TM height tended to decrease with increasing patient age (P < 0.001).These results were validated with post-hoc analysis using the least significant difference (no correction value) and Bonferroni correction (correction value) methods (Table 2 and Fig. 1).Scientific RepoRtS | (2020) 10:7115 | https://doi.

Purpose The purpose of this paper is to integrate stakeholder and international business (IB) theories to explore the relationship between the international diversification of emerging-market multinational corporations (EMNCs) and corporate social performance (CSP) in their home markets. While the IB literature generally assumes a positive effect from international diversification on CSP as a result of global learning, the study aims at investigating the complicated effects in the link to the stakeholder theory. Design/methodology/approach This paper used combined sources of public survey data (corporate social responsibility (CSR) of the Korean firms) and archival data (foreign direct investment and corporate data). A truncated regression is used for statistical model. Findings International diversification helps MNCs to enhance CSP in their home countries. Thus, EMNCs can develop CSR capabilities at the global level, thereby benefiting domestic stakeholders. Also, significant investment in domestic research and development (R&D) and advertising negatively moderates the relationship between international diversification and domestic CSP. In this regard, expanding R&D and advertising facilitates global competitiveness. Moreover, as international diversification increases, EMNCs may redirect resources and re-orient CSR policies toward foreign stakeholders. Consequently, the relationship between international diversification and domestic CSP weaken. Practical implications Acceleration in international diversification may weaken domestic CSP, which arises from transformation into the global enterprises. Originality/value The study highlights the difficulties of EMNCs in serving domestic stakeholders effectively when their businesses are increasingly internationalized.