Fig. 9
Aged brain-conditioned media induced a hyper-inflammatory LPS response in neonatal microglia ex vivo. a Brains were extracted from adult (8–10 weeks old) and aged (20 months old) male BALB/c mice and three 1-mm coronal brain sections from each mouse were used to condition media for 24 h. Conditioned media (CM) was then supplemented with fresh media at a 1:3 ratio. Unconditioned media (UCM) received identical treatment without contact with brain tissue. Primary neonatal microglia were cultured and plated at a density of 1 × 104 cells per well on a 96-well plate, incubated in conditioned medium (adult or aged) for 24 h. Next, primary cultures were stimulated with 1 μg/mL LPS and microglial RNA was collected 4 h later. b Viable cell count by condition as determined by MTS assay (n = 4 replicates / group). Normalized mRNA expression of Il1b (c), Il6 (d), and Tnf (e) in neonatal microglia incubated with adult or aged CM (n = 8 replicates / group). Bars represent the mean ± SEM. Means with * are different from Adult CM Vehicle (P < 0.05), and means with † are different from treatment-matched Adult CM (P < 0.05)