Figure 4.

Quantitative ISH analyses of HCN2 mRNA expression in developing hippocampus. (A) Expression levels of HCN2 mRNA evolve differentially in hippocampal regions: Expression remains relatively constant in CA1 pyramidal cell layer, whereas it increases with age in CA3 and DG principal cell layers. In CA3, HCN2 mRNA expression increases during the second postnatal week reaching mature levels by P11. (B) Representative autoradiographs show hippocampal HCN2 mRNA signal on P2, P11, P18, and P90 and the results of control ISH experiments using sense probe or excess (100×) unlabeled antisense probe in addition to labeled probe.