The altered expression of M_2 muscarinic receptor in the neurons of the pedunculopontine nucleus in 6-hydrodopamine unilaterally lesioned rats and its significance / 西安交通大学学报(医学版)

ABSTRACT

Objective To investigate the altered expression of muscarinic receptor 2 (M_2 receptor) in the pedunculopontine nucleus (PPN) of Parkinson's disease (PD) model rat by immunocytochemical technique and explore the role of M_2 receptor in etiopathogenesis and pathophysiological changes of PD. Methods Sixteen healthy SD rats were divided randomly into two groups. Rat monoclonal antibody against the M_2 receptor was used. Then we used positive cell counting and optical density as indicators to analyze the altered expression of M_2 receptor in PPN of PD model rats. Results The counting of M_2 receptor positive cells in the PPN was not obviously changed in normal rats and the unlesioned side of PD rats (P>0.05), whereas a significant decrease was observed when compared to that in normal rats and the lesioned side of PD rats, respectively (P<0.05). However, the positive intensity in the three groups did not differ significantly. Conclusion The results indicate that there was a degenerative death or receptor loss of M_2 receptor positive cells in the lesioned PPN of PD rats. The expression intensity of M_2 receptor positive cells without degenrative death or receptor loss was not affected. It was also found that the factor affecting the change of M_2 receptor positive cells in the PPN involved only one side.