OBJECTIVETo investigate the effects of chronic stress on the spatial learning-memory and the role of glial cell line-derived neurotrophic factor (GDNF) of prefrontal cortex (PFC) and hippocampus (HP) in different age mice.

METHODSThe chronic stress model mice in 21 days with multiple chronic unpredictable stressors were applied. The spontaneous behavior and spatial learning-memory ability of mice were tested, using Open field and Morris water maze task, and the expression of GDNF in HP and PFC were detected by immunohistochemical method.

RESULTSCompared with young mice, the spontaneous behaviors were significantly decreased and the spatial learning-memory function were significantly decreased (P < 0.05, P < 0.01) in aged mice. The GDNF expression in the CA3, DG of HP and PFC were significantly reduced in aged mice (P < 0.05, P < 0.01). After chronic stress, the spontaneous behaviors were remarkably decreased and the ability of spatial learning-memory of the stress group mice were significantly decreased (P < 0.05, P < 0.01) compared with those of the control group mice. The expression of GDNF in HP and PFC were remarkably reduced (P < 0.05, P < 0.01) in stress group mice. The aged stress mice had more serious changes after chronic stress.

CONCLUSIONThe brain aging and chronic stress in mice causes behavioral changes and the damage of spatial learning-memory function, and which may be nearly related to the expression of GDNF in HP and PFC.