Leah Wheaton
Research Mentor(s): Benjamin Singer
Mentor Department: Internal Medicine / Pulmonary and Critical Care Medicine
Authors: Leah Wheaton, Kate Giffin, Michael Newstead, Benjamin Singer
Session: Session 4 (1:00pm – 1:50pm)
Presentation Type: Oral
Abstract
Sepsis is associated with mental illnesses and cognitive deficits. Synapse loss is a mechanism of cognitive deficits in neuropsychiatric disorders and the hippocampus is a key brain area for cognition. Our goal is to see if the number of hippocampal synapses decreases in mice that have undergone sepsis compared to uninfected mice, and whether mice that express amyloid proteins as a model of early Alzheimer’s disease (5xFAD mice) are more vulnerable to synapse loss. The brains from mice that either underwent the cecal ligation and puncture model of sepsis or were uninfected were fixed via glyoxal fixation and sliced to 40 micrometers on a cryostat. We used immunofluorescence to stain brain tissue for the synaptic markers VGLUT1 or Bassoon in the hippocampus. VGLUT1 is an excitatory presynaptic protein and Bassoon is a presynaptic protein. Then the tissue was imaged on the SP8 confocal microscope and synapses, defined as puncta in the tissue, will were quantified in each group using FIJI image analysis software. We found that glyoxal fixation improves staining for synaptic markers compared to paraformaldehyde fixation. We have successfully stained a set of tissue from female and male mice 5 days after abdominal infection, which is when they are in the acute illness stage. We found a significant effect of genotype with lower density of Bassoon in 5xFAD mice, but no effect of sepsis at the 5 day timepoint. VGLUT1 analysis is still in progress. We plan to repeat these experiments with different antibodies and at later time points after infection. This research could help aid in the progression of treatments to combat the neuropsychological effects of sepsis by revealing one mechanism of brain dysfunction after sepsis.
