Alterations in the time-dependent expression levels of TNF-α and ribosomal S12 genes in neonatal rat brain microglia after treatment with LPS or Domoic acid. Levels of gene expression were quantified as described in Materials and Methods and were normalized to sl2 rRNA. Relative expression levels were calculated by dividing the experimental level at each time point by the level observed in the control. Expression is relative to steady-state levels in control (1.00). Data (relative expression level) is expressed as mean ± SE of 3 independent experiments. *p < 0.05 or **p < 0.01 vs. vehicle control.