Objective: To investigate whether pinching spine (PS, i.e. , a traditional Chinese manipulative therapy) is beneficial to ameliorating the depressive state (including behavioral deficit, retardative weight gain and decreased sucrose consumption) in a rat model of depression induced by chronic unpredictable stress (CUS) and to explore the candidate mechanism of action.
Methods: PS was performed on rats' spine once daily for 1 week after exposure to CUS. The open-field test, body weight measuring, and sucrose intake test were applied on different dates: before stress (d0), at the end of stress (d21) and after PS treatment (d28), respectively. Then the rats' hippocampuses were performed genome-wide microarray analysis, and the expression levels of several genes were evaluated by real-time polymerase chain reaction (PCR).
Results: Exposure to CUS resulted in decreases of behavioral activity and sucrose consumption, which were reversed significantly after PS treatment. The expression of several genes relevant to energy metabolism, anti-oxidation, and olfactory receptor, etc., were down-regulated, while the expression of those relevant to hemostasis, immunity-inflammation, and restriction of activities and ingestion, etc., were up-regulated in hippocampuses of rats exposed to CUS. PS treatment significantly inverted these changes. Furthermore, increase or decrease in gene expression evaluated by realtime PCR was concordant with up-regulated or down-regulated expression evaluated by microarray analysis.
Conclusion: PS showed a potential antidepressant-like effect, of which the action mechanism might be due to gene expression regulation in hippocampus.
Keywords: chronic unpredictable stress; depression; pinching spine.