Culture of isolated microglia from dissociated cortical tissue has promoted the in vitro study of microglial function and morphological characteristics (Giulian and Baker, 1986 ; Streit and Kincaid-Colton, 1995 ). However, cultures prepared in this manner demonstrate characteristic “ameboid” morphology, and are generally considered to be more activated than the normal, resting microglia foundin situ(Sedgwick et al., 1991 ). To reduce this problem, as well as to recreate a cellular architecture more typical of in vivo conditions, we have utilized an organotypic tissue slice method for culture of microglia (Czapiga and Colton, 1999 ; Gahwiler et al., 1997). This technique allows visualization of microglial morphology and the determination of certain microglial functional parameters, in a culture environment more reminiscent of the in vivo brain.
