ABSTRACT
<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Compared 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.</p><p><b>CONCLUSION</b>The 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.</p>