The paper I read for this week’s blog directly related to our work using MEMRI and the mapping of brain regions in a rat experimental design of runners versus sedentary animals. MEMRI is commonly used to map the functional and structural organization of the brain. By using manganese as a retrograde tracer, it is able to give a visualization of tracks in the brain. This paper, Eschenko et al, followed closely to the experimental design we are currently studying in the lab. The first experiment utilized 12 rats that received a subcutaneous injection of manganese chloride and were scanned over a period of 16 days. The second experiment utilized 6 rats and were injected with manganese chloride with the intraperitoneal technique. They were tested for a total of one week. Finally, in the third experiment, manganese was enhanced using osmotic pumps. The osmotic pumps were surgically implanted and were used to slowly release manganese over time to eliminate any toxicity that may occur in have adverse effects on the data or even may cause death. The pump was placed into the intraperitoneal space. The most interesting aspect of this paper was the use of the osmotic pump to slowly release manganese into the animal and monitor them over time. This contrasts our experiment in such that we administered an intraperitoneal injection once and scanned the animal over the course of 3 weeks. There results indicated that the osmotic pumps having a slow release of manganese is more manageable by the bodies homeostatic mechanisms and will not produce and toxic effects. Secondly, the method was explored the ability of functional brain mapping in naturally behaving rats.

This is an interesting technique used in the lab and directly relates to our experiment. Depending on the results of our current research, I would be curious to see if we could use an osmotic pump in our rats and compare the results of IP vs Osmotic pump.

Dean