Expression of PSD-95 in hippocampal CA1 region of morphine withdrawal rats in different dependent times

Objective. To observe the expression of postsynaptic density-95 (PSD-95) protein in hippocampal CA1 region of the withdrawn rats depended on morphine for different times and investigate the influence of morphine-withdrawal on addic tion memory. Methods. Animal models of the withdrawn rats in different morphine dependent times (1 week, 2 weeks, 4 weeks) were established. The rats’ behaviors and livings were observed. The expressions of PSD-95 protein with immunohistochemistry and PSD-95 mRNA with RT-PCR in hippocampal CA1 region were identified. Results. The expression of PSD-95 in hippocampal CA1 region decreased (P < 0.01) in the withdrawn group dependent on morphine for 1 week as compared with that in normal saline (NS) group, and it increased (P < 0.05) in the withdrawn group depended on morphine for 2 weeks as compared with that in morphine-dependent group for 1 week, but still decreased (P < 0.01) as compared with that in NS group, and it decreased the most in the withdrawn group depended on morphine for 4 weeks as compared with the other three groups (P < 0.01). Conclusion. The expression of PSD-95 in hippocampal CA1 region of the withdrawn rats depended on morphine decreased and might play a role in addiction memory. [Life Science Journal. 2008; 5(3): 27 – 39] (ISSN: 1097 – 8135).