Brugia Malayi - Clark Science Center - Smith College

Long-Term Fatigue Causes Morphological Changes in Microglia
Helen Queenan
It is important to understand where the most noticeable effects of fatigue are concentrated in the brain in order to find treatments
for this disorder. One factor that has been closely related in helping to understand this disease more fully is the activation of
microglia. Through inducing long-term fatigue in animals, either through exterior manipulation, such as drugs or through natural
causes, or age, we can examine and pinpoint where or what effects activated microglia may cause. The purpose of our study was
to determine differences between activated microglia in young and aged mice. It was also important to discover where in the brain
activated microglia are most concentrated during fatigue. With this, we can target that area and in the future create a drug that
specifically targets the microglia in that brain region. In order to accomplish this, a quantitative method needed to be tested and
finalized. The experiments conducted in order to answer some of these concerns included running immunocytohistochemistry
and obtaining a quantification method for the results from the immunocytohistochemistry. Female mice, young and aged, were
euthanized. Their brains were removed and frozen on dry ice. The brains were sliced at 20 micrometer sections and sliced via
a cryostat. Cryosections were then fixed and run through an immunocytohistochemistry protocol. At the end, sections were
incubated in DAB, dehydrated, and ready for analyses. Pictures were obtained and analyzed by Image J. Image J was used as a way
to compare brain regions, from a young and aged mouse, by quantifying the activated microglia in the brain regions. Results from
our experiments suggest that there is a morphological change in activated microglia in mice experiencing long term fatigue, and
a method found to effectively quantify microglia will prove effective when determining where, in which brain regions, activated
microglia are most concentrated. Future research would observe the differences in Interlukin-1 treated young mice in addition to a
difference between aged mice treated with Interlukin-1. (Supported by the Frances Baker Holmes Fund)
Advisor: Mary Harrington
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Figure 1: Hippocampus of (A) aged mouse (40X) and (B) young mouse (40X)
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Figure 2: Hippocampus of (A) aged mouse (4X) and (B) young mouse (4X)
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2012
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