Correlation of activity induced genes.

<p><b>A,</b> Two-dimensional correlation plot of activity induced gene expression levels. Six independent experiments were conducted for the 0 h control time point and three independent experiments for the time points 1, 4, 8, and 24 h. Hippocampal RNA of one mouse was hybridized to one DNA microarray. The plot indicates the correlation of expression profiles of all induced genes compared in control animals and in animals at indicated time points after the onset of kainic acid induced seizures. Correlation coefficients range from 0.97 (bright yellow color code) to 0.99 (red color code). Arrays were clustered using average linkage cluster analysis with a correlation metric distance. <b>B</b>, Correlation of genes induced by seizure in mice of different genetic backgrounds. Hippocampal RNA from control mice and mice sacrificed 4 h after the onset of seizure was analyzed. RNA from one animal (n = 3) was hybridized to one microarray and genes induced 4 h after onset of seizures in C57Bl/6J and hybrid 129/Sv×C57Bl/6J mice were compared. Logarithmic fold changes (Log-FC) are shown. Correlation coefficient r = 0.6 is indicated.