Effect of High cholesterol Diet and Stress on CA1 &CA3 Regions of Hippocampus

Back ground: Dyslipidemia induced cognitive impairment is a matter of controversy. The effects of dyslipidemia coupled with exposure to stress on the hippocampal sub-regions are little known. Aim: To determine the effect of high fat diet consumption and prolonged exposure to stress on the hippocampal CA1 & CA3 regions. Materials & methods: Adult male Wistar rats of 2months old were randomly divided into three groups. (n=6). Group-I received normal diet (control), Group-II received high cholesterol diet (HCD) and Group-III received high cholesterol diet and stress (HCD + STS). Body weight, serum total cholesterol (TC), triglycerides (TG) was measured. The spatial memory was assessed by Morris water maze. Rats were sacrificed on 96th day; brains were separated and Coronal sections of CA1 and CA3 areas of hippocampus were processed by Cresyl violet staining and the number of viable neurons was quantified. Results: Compared to control, (HCD) fed group-II and (HCD + STS) group-III induced showed significant (p<0.001, p<0.01) increase in body weight, TC and TG levels. Similarly in Morris water maze animals of group-II (HCD) and III (HCD + STS) exhibited significant increase in latency to enter target quadrant (p < 0.001, p < 0.05) and significant decrease (p < 0.001, p < 0.05) in the time spent in the target quadrant. Cresyl violet staining of hippocampus also revealed significant (p < 0.001, p < 0.01) decrease in number of viable neurons in CA1 and CA3 regions among group-II and III respectively compared to control group. Conclusion: These findings demonstrated that HCD and HCD + STS had effect on memory and was neurotoxic to hippocampus. These findings help us to understand how diet rich in cholesterol and stress affect the hippocampus.