Zhang Qiao-jun
2010
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Quality indicators
Journal
Journal of Xi'an Jiaotong University
Abstract
Objective To explore the effects of oxotremorine M(Oxo-M),muscarinic acetylcholine receptor agonist,on spontaneous firing rate of neurons of pedunculopontine nucleus(PPN) in normal and 6-hydroxydopamine(6-OHDA)-lesioned rats.Methods Change in the firing activity of PPN neurons was observed by extracellular recording in vivo and local injection of Oxo-M in the PPN.Results The results showed that the mean firing rate of PPN neurons in the lesioned rats was significantly increased compared to that in normal rats(P0.01),and that the firing pattern of the neurons changed toward a more irregular firing after the lesion(P0.001).Intra-PPN injection of Oxo-M induced increase,decrease or no change in the firing rate of PPN neurons in both the normal and 6-OHDA-lesioned rats.However,the mean firing rate of PPN neurons in normal rats remained unaltered by the stimulation of M receptors,but the mean firing rate of PPN neurons in the lesioned rats decreased significantly by intra-PPN injection of Oxo-M(P0.001).Conclusion M receptor agonist inhibits the activity of the PPN neurons in lesioned rats;the action mechanism of the agonist is complicated,involving not only postsynaptic but also presynaptic M receptors located in different sites within the PPN.