Grant: Discovery Grants Program - Individual

Manganese Enhanced MRI (MEMRI): A Molecular Imaging Tool to Study Neuron Function Proposed Research: This research will use Magnetic Resonance Imaging to image brain function of rats performing memory and skilled paw movements. Manganese is an important trace element in living cells and is naturally present. The tool that will allow me to do this is a newly developed technique called manganese-enhanced magnetic resonance imaging or MEMRI.  In the MEMRI technique, a solution containing very small amounts of manganese is injected in the animal. The manganese ion in solution has the same electron configuration as a calcium ion. Cells like Neurons in the brain have calcium channels that transport calcium in and out of the cells. Calcium is involved in the activity or firing of the brain cells. Manganese passes through the calcium channels and gets into the cells. Once the manganese is in the cells, it will be transported around the cells. The magnetic properties of manganese are such that the presence of manganese will make a bright spot on an MRI image. Since the uptake of the manganese, is proportional to the activity of the brain cells, the bright spots in the images are related to brain activity.   The MEMRI technique has been successful in imaging regions of brain activity. The beauty of this technique is that the manganese can be injected, a task such as training the rat to find a hidden platform in a swimming pool performed and then the MRI imaging taken.  This research will attempt to use MEMRI with behavioural task in rats to develop a new tool to look at brain function. Previous literature has concluded that in the concentrations used in MEMRI, that it does not affect the rats. However, high levels of manganese play a role in Parkinson's disease. Our research will look carefully at the skilled paw movements of the rats to look for any indications that there is an adverse affect on the animal. And finally, I will attempt to improve the imaging methods to be more sensitive to the presence of manganese so that the dose can be lowered.