Strain differences in the expression of cholinergic markers in the hippocampus of ApoE-knockout and C57BL/6J mice

Our recent study suggests that mice deficient in ApoE may exhibit impaired learning and memory. Here we designed the present study to investigate the association between ApoE deficiency and cholinergic markers expression in the hippocampus of ApoE-knockout (ApoE-KO) and wild-type (WT) mice. Hippocampal slices were collected and the mRNA levels of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) and the protein level of ChAT were analyzed. We show that ApoE-KO exhibited a distinctly lower ChAT mRNA and protein levels in the hippocampus compared with WT mice. There were no strain effects on AChE mRNA. Our data provide evidence supporting the role of ApoE in the expression of ChAT, which may suggest a possible link between cholinergic deficit and poorer performance in ApoE-KO mice.