Manganese Enhanced Magnetic Resonance Imaging

Prof. Gary Egan
Email: gary.egan(at)florey.edu.au

Manganese enhanced magnetic resonance imaging (MEMRI) is a novel neuroimaging technique first introduced by Lin and Koretsky in 1997. In this technique, bivalent manganese ion (Mn2+) is used as a tracer for Ca2+, an important substrate for neurotransmission. By monitoring the transportation of Ca2+ between the cells and synapses, MEMRI can be used in vivo to trace neuronal tracts and to study brain function dynamically.

Mn2+ can be used as the tracer for Ca2+ is because it has two special properties. Firstly, Mn2+ has a physical size which is similar to that of Ca2+, and is considered as a Ca2+ analogue in many biological systems; Mn2+ can be taken up by neurons and transported through the voltage-gated Ca2+ channels and the neuronal microtubule system. Secondly, Mn2+ is a paramagnetic ion, which shortens the proton T1 relaxation time of the water molecules in its vicinity, and thus can be used as an MRI contrast agent. Since its introduction, MEMRI has been attracting more and more interest from neurobiology researchers.

The primary goal of this project will be the development and application of MEMRI method in addiction and epilepsy mice models. To achieve this goal the project will pursue three major objectives:

  • to develop and set up a standard MEMRI protocol in mice;
  • to investigate the brain dynamic activation during drug or alcohol administration and withdrawal period; and
  • to investigate the mechanism of epilepsy in a mouse model.

Project References

  1. Pautler R G, Koretsky A P. Tracing odor-induced activation in the olfactory bulbs of mice using manganese-enhanced magnetic resonance imaging. NeuroImage, 2002. 16(2):441~448.
  2. Pautler R G, Silva A C,Koretsky A P. In vivo neuronal tract tracing using manganese-enhanced magnetic resonance imaging. Magn Reson Med, 1998. 40(5):740~748.
  3. Van der Linden A, Verhoye M, Van Meir V, et al. In vivo manganese-enhanced magnetic resonance imaging reveals connections and functional properties of the songbird vocal control system. Neuroscience, 2002. 112(2):467~474.
  4. Xin Y, Youssef Z W, Dan H S, et al . In vivo auditory brain mapping in mice with Mn-enhanced MRI, Nature Neuroscience, 2005.