Ultrastructural localization of HCN1 in middle molecular layer (MML) of dentate gyrus.

<p>a) Light micrographs of silver-intensified immunogold-stained hippocampal slices show the presence of a thin band of HCN1 immunoreactivity in MML in the TRIP8b^−/− (arrows), but not in the wildtype mice. Note also the lack of HCN1 enrichment in stratum lacunosum-moleculare (SLM, asterisks) of CA1 in the TRIP8b^−/−-section, as described by Lewis et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032181#pone.0032181-Lewis2" target="_blank">[12]</a> (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032181#pone-0032181-g001" target="_blank">Fig. 1d–f</a>). b, c) Electron micrographs of serial sections showing immunopositive axonal boutons in a TRIP8b^−/− mouse, making both perforated (arrow) and nonperforated synapses with dendritic spines in MML. Abbreviations: at, axon terminal; sp, spine. d) Percentage of axonal boutons, immunopositive for HCN1, making axospinous synapses in MML in wildtype (black) and TRIP8b^−/− mice (white). e) Average number of particles per synaptic bouton in wildtype (black) and TRIP8b^−/− mice (white). Data were obtained from two mice of each genotype, and based on analyses of 25 synaptic boutons from each mouse (100 axonal boutons total) from the MML. Serial ultrathin sections were obtained from slices similar to those shown in (a).