Figure 6.

HCN1 mRNA expression in the CA1 pyramidal cell layer of three groups of human hippocampi. HCN1 mRNA signal (hatched bars, right y-axis) is coplotted with CA1 pyramidal cell layer neuronal densities (solid bars, left y-axis). The autopsy (AUT) tissue is compared with epileptic hippocampus with (HS) or without (NHS) sclerosis. A drastic (^*) reduction of CA1 neuronal densities is found in HS hippocampus and is accompanied by a tendency to lower HCN1 mRNA levels. As shown in Figure 3D, the HCN1 mRNA signal over the depleted HS pyramidal cell layer originates, at least partially, from the preserved interneuronal populations. It should be noted that massive cell loss in CA1 was found in specimens with either mild or severe reduction of GC densities so that the HS group is treated here as a single population. CA, Cornu ammonis.