Limits...
Differential expression of hyperpolarization-activated cyclic nucleotide-gated channel subunits during hippocampal development in the mouse.

Seo H, Seol MJ, Lee K - Mol Brain (2015)

Bottom Line: Each HCN channel isoform showed subfield-specific expression within the hippocampus from postnatal day 7, and only HCN4 was found in glial cells in the stratum lacunosum moleculare at this developmental stage.Furthermore, the immunolabeling for all these isoforms was colocalized with parvalbumin immunolabeling in interneurons of the CA field and in the dentate gyrus.Our mapping data showing the temporal and spatial changes in the expression of HCN channels suggest that HCN1, HCN2, and HCN4 subunits may have distinct physiological roles in the developing hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Brain Science & Engineering Institute, Kyungpook National University Graduate School of Medicine, 2-101, Dongin-dong, Jung-gu, Daegu, 700-842, South Korea. hseo@knu.ac.kr.

ABSTRACT

Background: Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels help control the rhythmic activation of pacemaker neurons during brain development. However, little is known about the timing and cell type specificity of the expression of HCN isoforms during development of the hippocampus.

Results: Here we examined the developmental expression of the brain-enriched HCN1, HCN2, and HCN4 isoforms of HCN channels in mouse hippocampus from embryonic to postnatal stages. All these isoforms were expressed abundantly in the hippocampus at embryonic day 14.5 and postnatal day 0. Each HCN channel isoform showed subfield-specific expression within the hippocampus from postnatal day 7, and only HCN4 was found in glial cells in the stratum lacunosum moleculare at this developmental stage. At postnatal days 21 and 56, all HCN isoforms were strongly expressed in the stratum lacunosum moleculare and the stratum pyramidale of the Cornu Ammonis (CA), as well as in the hilus of the dentate gyrus, but not in the subgranular zone. Furthermore, the immunolabeling for all these isoforms was colocalized with parvalbumin immunolabeling in interneurons of the CA field and in the dentate gyrus.

Conclusions: Our mapping data showing the temporal and spatial changes in the expression of HCN channels suggest that HCN1, HCN2, and HCN4 subunits may have distinct physiological roles in the developing hippocampus.

Show MeSH
Expression of HCN subunits in doublecortin (DCX)-positive cells of the dentate gyrus at P21. (A-L): These images show our results on double immunofluorescence for HCN subunits and DCX. In the DCX-immunopositive subgranular zone we did not find labeling for HCN1 (A-D), HCN2 (E-H), or HCN4 (I-L). Scale bars = 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4352274&req=5

Fig6: Expression of HCN subunits in doublecortin (DCX)-positive cells of the dentate gyrus at P21. (A-L): These images show our results on double immunofluorescence for HCN subunits and DCX. In the DCX-immunopositive subgranular zone we did not find labeling for HCN1 (A-D), HCN2 (E-H), or HCN4 (I-L). Scale bars = 20 μm.

Mentions: In the dentate gyrus, immunolabeling for HCN1 was observed in the GCL and in a restricted population of cells of the hilus (Figure 3M-P). Immunoreactivity for HCN2 was strong throughout the dentate gyrus, but the most prominent expression was observed in the ML and hilus (Figure 4M-P). On the other hand, immunoreactivity for HCN4 was relatively low throughout the dentate gyrus (Figure 5M-P). HCN1- and HCN2-positive cells were located in the GCL (Figures 3M and 4M), but not in the subgranular zone (Figure 6A-H), which was labeled with doublecortin (DCX) as a marker of adult neurogenesis. HCN4-immunoreactive cells were generally located in the superficial part of the GCL, adjacent to the ML (Figure 5M), but not in the subgranular zone (Figure 6I-L), in a similar manner to HCN1 and HCN2 subunits. In addition, several PV-immunopositive interneurons showed HCN1 (Figure 3M-P), HCN2 (Figure 4M-P), and HCN4 (Figure 5M-P) expression in the GCL and hilus.Figure 6


Differential expression of hyperpolarization-activated cyclic nucleotide-gated channel subunits during hippocampal development in the mouse.

Seo H, Seol MJ, Lee K - Mol Brain (2015)

Expression of HCN subunits in doublecortin (DCX)-positive cells of the dentate gyrus at P21. (A-L): These images show our results on double immunofluorescence for HCN subunits and DCX. In the DCX-immunopositive subgranular zone we did not find labeling for HCN1 (A-D), HCN2 (E-H), or HCN4 (I-L). Scale bars = 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4352274&req=5

Fig6: Expression of HCN subunits in doublecortin (DCX)-positive cells of the dentate gyrus at P21. (A-L): These images show our results on double immunofluorescence for HCN subunits and DCX. In the DCX-immunopositive subgranular zone we did not find labeling for HCN1 (A-D), HCN2 (E-H), or HCN4 (I-L). Scale bars = 20 μm.
Mentions: In the dentate gyrus, immunolabeling for HCN1 was observed in the GCL and in a restricted population of cells of the hilus (Figure 3M-P). Immunoreactivity for HCN2 was strong throughout the dentate gyrus, but the most prominent expression was observed in the ML and hilus (Figure 4M-P). On the other hand, immunoreactivity for HCN4 was relatively low throughout the dentate gyrus (Figure 5M-P). HCN1- and HCN2-positive cells were located in the GCL (Figures 3M and 4M), but not in the subgranular zone (Figure 6A-H), which was labeled with doublecortin (DCX) as a marker of adult neurogenesis. HCN4-immunoreactive cells were generally located in the superficial part of the GCL, adjacent to the ML (Figure 5M), but not in the subgranular zone (Figure 6I-L), in a similar manner to HCN1 and HCN2 subunits. In addition, several PV-immunopositive interneurons showed HCN1 (Figure 3M-P), HCN2 (Figure 4M-P), and HCN4 (Figure 5M-P) expression in the GCL and hilus.Figure 6

Bottom Line: Each HCN channel isoform showed subfield-specific expression within the hippocampus from postnatal day 7, and only HCN4 was found in glial cells in the stratum lacunosum moleculare at this developmental stage.Furthermore, the immunolabeling for all these isoforms was colocalized with parvalbumin immunolabeling in interneurons of the CA field and in the dentate gyrus.Our mapping data showing the temporal and spatial changes in the expression of HCN channels suggest that HCN1, HCN2, and HCN4 subunits may have distinct physiological roles in the developing hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Brain Science & Engineering Institute, Kyungpook National University Graduate School of Medicine, 2-101, Dongin-dong, Jung-gu, Daegu, 700-842, South Korea. hseo@knu.ac.kr.

ABSTRACT

Background: Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels help control the rhythmic activation of pacemaker neurons during brain development. However, little is known about the timing and cell type specificity of the expression of HCN isoforms during development of the hippocampus.

Results: Here we examined the developmental expression of the brain-enriched HCN1, HCN2, and HCN4 isoforms of HCN channels in mouse hippocampus from embryonic to postnatal stages. All these isoforms were expressed abundantly in the hippocampus at embryonic day 14.5 and postnatal day 0. Each HCN channel isoform showed subfield-specific expression within the hippocampus from postnatal day 7, and only HCN4 was found in glial cells in the stratum lacunosum moleculare at this developmental stage. At postnatal days 21 and 56, all HCN isoforms were strongly expressed in the stratum lacunosum moleculare and the stratum pyramidale of the Cornu Ammonis (CA), as well as in the hilus of the dentate gyrus, but not in the subgranular zone. Furthermore, the immunolabeling for all these isoforms was colocalized with parvalbumin immunolabeling in interneurons of the CA field and in the dentate gyrus.

Conclusions: Our mapping data showing the temporal and spatial changes in the expression of HCN channels suggest that HCN1, HCN2, and HCN4 subunits may have distinct physiological roles in the developing hippocampus.

Show MeSH