Fig. 3.

Differential neurotoxicity in mixed neuron–glia cultures from various brain regions after treatment with LPS. Mixed neuron–glia cultures were prepared from hippocampal, cortical, or mesencephalic tissues of embryonic day 16–17 rats. Cultures were treated for 72 hr with vehicle alone or 1 μg/ml LPS (A, B) or graded concentrations of LPS (C) and then immunostained with an antibody to the neuronal cytoskeletal protein MAP-2. A, Immunocytochemical analysis of MAP-2-positive neurons. Scale bar, 100 μm. B, Quantification of MAP-2-immunostained cell bodies. Significant degeneration of MAP-2-IR neurons after LPS treatment was observed in mesencephalic cultures only. For reference, the mean number of MAP-2-IR cells per well in the vehicle-treated hippocampal, cortical, and mesencephalic cultures were 6.7 × 10⁴, 6.0 × 10⁴, and 6.4 × 10⁴, respectively. C, LPS-induced loss of MAP-2-positive neurons in the mesencephalic cultures was dependent on the concentrations of LPS. The data are expressed as a percent of the total number of MAP-2-IR cell bodies present in the vehicle-treated control cultures. The data represent the mean ± SEM of at least five wells taken from three independent experiments. *p < 0.0001 compared with the vehicle-treated control cultures prepared from the rat mesencephalon.