Figure 1.

CB₁ receptor mRNA level is downregulated in the epileptic human hippocampus. A, Representative real-time PCR measurement of CB₁ cannabinoid receptor mRNA level in control and epileptic human hippocampus. Note that the housekeeping gene β-actin reaches threshold of normalized fluorescence intensity at identical values in both the control and epileptic hippocampus. In contrast, when CB₁ cannabinoid receptor mRNA is measured, the exponential phase begins later and reaches threshold approximately one cycle later in a representative sample from the epileptic hippocampus. One cycle difference in the cycle threshold value indicates ∼50% difference in the original mRNA level because of the exponential nature of the PCR. B, Gene expression level of the CB₁ receptor is robustly downregulated in both nonsclerotic (n = 7) and sclerotic (n = 6) epileptic hippocampi compared with control tissue (n = 7). Note that the direction and magnitude of expression level changes were identical in parallel experiments using two distinct housekeeping genes, β-actin and GAPDH. C, Bar graphs demonstrate that neither postmortem delay nor sustained anesthesia influence CB₁ mRNA level in the mouse hippocampus. Data are presented as mean expression ratio ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001.