LPS treatment decreases dendritic spine densities of CA1 pyramidal neurons in organotypic hippocampal slice cultures that are prevented by DHA. A Examples of dendrites segments from CA1 pyramidal neurons showing control-, LPS-, DHA- and LPS + DHA-treated dendritic spine morphologies. In the presence of LPS, there is a decrease in spine densities. Higher LPS concentration (1 μg/ml) causes a more pronounced spine decrease compared to lower concentration of LPS (100 ng/ml). With DHA alone, there is no difference in dendritic spine morphologies compared to control. If the LPS-treated cultures are pre-incubated with DHA, no spine loss is observed. Lower (100 ng/ml) or higher LPS (1 μg/ml) concentrations do not differ in their response to DHA pre-treatment. Scale bar 2 μm. B Dendritic spine density under various treatments in CA1 pyramidal neurons. *p < 0.05.