The MRNA And MiRNA Expression Of Dopamine Related Genes In The Rats With Acute And Chronic Stress

Objectives To explore the effects of acute and chronic stress on the expression of dopamine related genes(including tyrosine hydroxylase,dopamine transporter,dopamine D1 receptor,dopamine D2 receptor,dopamine D3 receptor and prostate apoptosis response-4)in nucleus accumbens of depressive animal models; To explore differential expression of micro RNA profile in chronic unpredictable mild stress rats and normal controls.Methods 1. In the acute stress trial,16 SD rats were randomly assigned to acute stress group or control group. Each group had 8 rats. Rats in acute stress group underwent foot shock for 40 minutes once a day for 3 days. In the CUMS trial, 16 SD rats were randomly assighed to chronic stress group or control group. Each group had 8 rats. Rats in chronic stress group underwent 1-2 unpredictable mild stress each day for 6 weeks.Body weight was measured each week;Sugar preference test was evaluated every 3 weeks. Open field was used to measure animals' behavior. Animals were sacrificed after the two trials and nucleus accumbens were taken.2. The mRNA expression of dopamine related factors were measured by RT-PCR.3. Select two samples of nucleus accumbens from each group in the CUMS trial and miRNA sequencing was used to detect differential expression of miRNA profile.Results1. Rats' behavior reduced with foot shock proceeding in the acute stress trial.2. There were no statistically differences in mRNA expression of dopamine related genes between the two groups in the acute stress trial.3. Rats in CUMS group had lower weight gain(240.91�27.59 g vs 156.30�15.78g) and sugar preference(.73 �.10 vs.60 �.14) than control group, while the behavior in open field increased in CUMS group compared with control group.4. The mRNA expression of dopamine related genes had no difference between two groups in the CUMS trial.5. 25 miRNAs were obviously down-regulated and 2 up-regulated in CUMS group. Conclusions1. The mRNA expression of dopamine related genes may not be affected by either acute stress or CUMS in rats.2. The expression of some miRNAs may be changed by chronic unpredictable mild stress.