Figure 2.
Time course-dependent hyperactivation of microglia in the RVM after CCI. A, CD11b immunostaining in the RVM. a, Low power of a section at the rostral medulla level. b, Enlarged RVM region corresponding to the small rectangle area in a. CD11b expression is enhanced at 3 d (c) but not 14 d (d) after CCI-ION, compared with CD11b immunoreactivity in naive animal (b). B, Iba1 immunostaining in the RVM. Enhanced Iba1 expression is observed at 3 d (b) and declined to near control expression levels at 14 d (c) and 28 d (d) after CCI, compared with naive animal (a). C, Western blots illustrating CCI-induced short-lasting increase in CD11b in RVM tissues. Compared with naive rats, CD11b expression is temporarily increased at the 1–3 d time points but not at 14 and 28 d in both sham-operated (−) and CCI-ION (+) rats. The asterisks indicate significant differences from the naive rats (*p < 0.05; n = 3 per time points). D, Local tissue anesthesia (+), compared with saline injection (−), completely blocks sham operation-induced increase in CD11b in the RVM at 3 d, when compared with naive rats [sham (−) vs naive, p < 0.05; n = 3 per group]. Scale bars: Aa, 0.5 mm; Ad (for Ab–d), Bd (for Ba–d), 0.025 mm. NGC, Nucleus reticularis gigantocellularis. Error bars indicate SEM.
