Fig. 8. Effect of a cPLA₂ inhibitor and arachidonic acid on surface GluR2 expression in Purkinje dendrites. (A) Immunocytochemistry with polyclonal antibodies to the GluR2 N-terminus revealed the surface expression of GluR2 receptors on dendrites with deconvolution microscopy. Cerebellar cultures were stimulated with 200 nM PMA for 20 minutes and 30 µM AMPA for 1 minute in the absence or presence of 10 µM pyrrophenone, and were then washed with HBSS. At 120 minutes after the wash, the cells were processed for immunostaining. Scale bar: 5 µm. (B) Time course of the change in mean intensity of GluR2 immunoreactivity in dendrites. Data are shown as a percentage of control samples. The cPLA₂ inhibitor restored the prolonged reduction of postsynaptic GluR2 expression on Purkinje dendrites that were stimulated with PMA and AMPA. The values were means ± s.e.m. (n=6-9). ^*P<0.05, ^***P<0.001. (C,D) Purkinje cells were stimulated with 200 nM PMA for 20 minutes in the absence or presence of 200 µM arachidonic acid (AA) and then washed with HBSS. At 120 minutes after the wash, the cells were processed for immunostaining of the expression of GluR2 on the dendrites. Scale bar: 10 µm. The values are means ± s.e.m. (n=6-9). ^**P<0.01.