Speaker: Tong Wu, Queensland Brain Institute, University of Queensland
Title: Functional brain network study on wild type and DISC1 transgenic mice
Abstract: Major mental disorders such as schizophrenia, bipolar disorder and major depression create a heavy social burden and remain poorly treated. The gene Disrupted-in-Schizophrenia 1 (DISC1) is well-known to be significantly associated with these disorders and plays a substantial role in influencing a range of shared endophenotypes underlying them. Resting-state functional magnetic resonance imaging (rs-fMRI) is a powerful technique being applied to more than 30 different kinds of brain disorders and different species. Specifically, altered functional connectivity (FC) and network topologies are proposed to be plausible imaging endophenotypes of psychotic disorders. However, little is known about the direct effects of gene dysfunction, such as DISC1 mutations, on resting-state brain activations. Characterising the phenotypes of DISC1 in transgenic mice using rs-fMRI would provide valuable insights into the mechanism of how it influences the brain. Before characterizing disease phenotypes in mouse models, it is necessary to understand how the mouse brain functions in normal states. Anaesthesia is currently an integrated part of most mouse rs-fMRI experiments. It influences blood-oxygenation-level-dependent (BOLD) fMRI signals via modulation of neurovascular coupling and brain metabolism, and hence alters FC and topologies of resting-state networks (RSNs). Investigating FC and its changes associated with genes therefore initially requires an understanding of the anaesthetics. Furthermore, various anaesthetic protocols are adopted by different labs leading to difficulties in result comparisons. In this talk, I’ll show the results from a comparative study on how different and commonly used anaesthetics influence regional connectivity and funcitonal network organizations in mice. Based on the understanding of anaesthesia and the available experimental conditions, we chose one agent to facilitate the study on DISC1 mice. Behavioral experiments (Y maze and fear conditioning) were performed before in vivo rs-fMRI experiments. We observed no differences in behavioral assays, but subtle differences in the functional module affiliations of the amygdala in the transgenic mouse group. These results may provide preliminary references to the ongoing mouse rs-fMRI research, facilitate comparisons across labs and help to translate findings of transgenic mouse studies and human research.
Level 7 Auditorium, QBI Building (#79), St Lucia Campus
Your attendance at these seminars is both welcomed and encouraged.
For a list of upcoming seminars at QBI, go to www.qbi.uq.edu.au/neuroscience- seminars.