Pilot Study: The role of chronic stress on brain microvessel density in male and female mice

Abstract

The cerebrovasculature, an intricate configuration of blood vessels, is responsible for the exchange of blood to and from the brain. Reduction of cerebrovascular vessels can reduce or prevent the flow of nutrients & oxygen that is necessary for proper brain function and increase risk of cerebrovascular diseases. Chronic stress is also a risk factor to various cerebrovascular diseases.In this pilot study, brain microvessel density in both female and male chronically stressed mice were analyzed. Beginning at the age of 18 weeks, mice were subjected to the unpredictable chronic mild stress (UCMS) paradigm for 5 days a week/seven hours a day for 8 weeks. Upon euthanization brain samples were flash frozen and sectioned at 8um using a cryostat. Immunofluorescence was utilized to observe endothelial cells via a CD31 antibody. Images were taken using a Nikon Eclipse 800 at a 40X objective and analyzed and quantified for density using ImageJ.Preliminary data (n=3/group) suggest that the male mice have a 26% higher microvessel density compared to females (p<0.05). When stressed, males exhibit a 17% lower microvessel density whereas stressed females did not display a loss in microvessel density (p<0.05).Here we showed that the brain of male and female mice can be physiologically diverse in microvessel density and that males and females display a different response when exposed to chronic stress.Support or Funding InformationNIH Cobra Grant 5P20GM109098; NIH INBRE P20GM103434