Morphometric Investigation of Neurons in the Hippocampal CA1, CA3 Areas and Dentate Gyrus in a Rat Model of Sepsis

Approximately, half of the patients with progressive sepsis develop encephalopathy, but there is scarce knowledge onto question that how the sepsis associated encephalopathy contributes brain dysfunction. Hippocampus is one of the most vulnerable regions during experimental sepsis. In the present study, effects of sepsis on the neuronal density and morphology in CA1, CA3 and DG areas were investigated in a rat model of intraperitoneal sepsis. Twenty-four Wistar rats were divided into three different groups: faecal peritonitis group, sham-operated and un-operated control groups. Pyramidal neuron volume density was significantly higher in CA1 area of the faecal peritonitis group compared to both un-operated (p<0.05) and sham-operated (p<0.05) groups. Pyramidal neuron volume density was also significantly higher in CA3 area of the faecal peritonitis group compared to both un-operated (p<0.05) and shamoperated (p<0.05) groups. Mean nuclear diameter of pyramidal neurons in CA1 area of the faecal peritonitis group was significantly lower (p<0.05) compared to un-operated control group. Dark, shrunken neurons were frequently observed and neuroglial cells appeared to be prevalent in the faecal peritonitis group compared to control groups. These results collectively suggest that intraperitoneal sepsis does not initiate cell death in the early stages of sepsis, although morphological signs of neurodegeneration start to appear.