Left−Right Asymmetry Defect in the Hippocampal Circuitry Impairs Spatial Learning and Working Memory in iv Mice

Although left-right (L−R) asymmetry is a fundamental feature of higher-order brain function, little is known about how asymmetry defects of the brain affect animal behavior. Previously, we identified structural and functional asymmetries in the circuitry of the mouse hippocampus resulting from the asymmetrical distribution of NMDA receptor GluR ε2 (NR2B) subunits. We further examined the ε2 asymmetry in the inversus viscerum (iv) mouse, which has randomized laterality of internal organs, and found that the iv mouse hippocampus exhibits right isomerism (bilateral right-sidedness) in the synaptic distribution of theε2 subunit, irrespective of the laterality of visceral organs. To investigate the effects of hippocampal laterality defects on higher-order brain functions, we examined the capacity of reference and working memories of iv mice using a dry maze and a delayed nonmatching-to-position (DNMTP) task, respectively. The iv mice improved dry maze performance more slowly than control mice during acquisition, whereas the asymptotic level of performance was similar between the two groups. In the DNMTP task, the iv mice showed poorer accuracy than control mice as the retention interval became longer. These results suggest that the L−R asymmetry of hippocampal circuitry is critical for the acquisition of reference memory and the retention of working memory

Assessing medical technologies in development - A new paradigm of medical technology assessment

Objective: Our study aims to provide a practical contribution to the field of medical technology assessment within a new paradigm. This paradigm indicates the need for more comprehensive technology assessments in the development stage of a new technology. Method: We introduce a method, based on Saaty's Analytic Hierarchy Process, which quantitatively supports discussions between the various actors that shape the technology's development and diffusion. These discussions focus on technical, medical, social, and economical requirements relevant to the design and diffusion of the new technology. Discussion: In contrast to more traditional technology assessments, our method encompasses the perspectives of the diverse actors in the social context of technology development and diffusion. It influences their decision making on technology design and diffusion in order to improve this technology's later clinical as well as social effectiveness