Limits...
Distinct axo-somato-dendritic distributions of three potassium channels in CA1 hippocampal pyramidal cells.

Kirizs T, Kerti-Szigeti K, Lorincz A, Nusser Z - Eur. J. Neurosci. (2014)

Bottom Line: The Kv2.1 subunit was found in somatic, proximal dendritic and AIS plasma membranes at approximately the same densities.A quasi-linear increase in the Kir3.2 subunit density along the dendrites of PCs was detected, showing no significant difference between apical dendritic shafts, oblique dendrites or dendritic spines at the same distance from the soma.Our results demonstrate that each subunit has a unique cell-surface distribution pattern, and predict their differential involvement in synaptic integration and output generation at distinct subcellular compartments.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony Street 43, Budapest, Hungary.

Show MeSH

Related in: MedlinePlus

Somato-dendritic distribution of the Kir3.2 subunit in CA1 PCs. (A) A low-magnification image of a CA1 PC soma with an emerging apical dendrite (Ap.Dendr) labelled for the Kir3.2 subunit (10-nm gold). (B and C) Higher magnification images of the boxed areas shown in panel A. (D) A spiny apical dendrite from the distal (dist.) part of SR is shown. (E) A higher magnification image of the boxed area shown in D. (F) A low-magnification image of a spiny tuft dendrite (Tuft Dendr.) in the SLM labelled for the Kir3.2 subunit (10 nm gold). (G) A higher magnification image of the boxed area shown in F. (H and I) Gold particles for the Kir3.2 subunit are associated with the P-faces of spiny oblique dendrites (Obl.Dendr.) in the proximal (H) and distal (I) parts of SR. (J) Bar graphs demonstrate the densities (mean ± SD) of gold particles in different subcellular compartments of CA1 PCs. *Values that are significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P < 0.01; n = 3 rats). The inset shows that gold particle density in the AIS was not significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P = 0.95; n = 3 rats). The AISs were identified based on their immunopositivity for pan-NF. BG, background; mid., middle; Sp, spine; AxTerm, axon terminal. Scale bars, 1 μm (A), 500 nm (D and F), 250 nm (H and I), 100 nm (B, C, E and G).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4150533&req=5

fig07: Somato-dendritic distribution of the Kir3.2 subunit in CA1 PCs. (A) A low-magnification image of a CA1 PC soma with an emerging apical dendrite (Ap.Dendr) labelled for the Kir3.2 subunit (10-nm gold). (B and C) Higher magnification images of the boxed areas shown in panel A. (D) A spiny apical dendrite from the distal (dist.) part of SR is shown. (E) A higher magnification image of the boxed area shown in D. (F) A low-magnification image of a spiny tuft dendrite (Tuft Dendr.) in the SLM labelled for the Kir3.2 subunit (10 nm gold). (G) A higher magnification image of the boxed area shown in F. (H and I) Gold particles for the Kir3.2 subunit are associated with the P-faces of spiny oblique dendrites (Obl.Dendr.) in the proximal (H) and distal (I) parts of SR. (J) Bar graphs demonstrate the densities (mean ± SD) of gold particles in different subcellular compartments of CA1 PCs. *Values that are significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P < 0.01; n = 3 rats). The inset shows that gold particle density in the AIS was not significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P = 0.95; n = 3 rats). The AISs were identified based on their immunopositivity for pan-NF. BG, background; mid., middle; Sp, spine; AxTerm, axon terminal. Scale bars, 1 μm (A), 500 nm (D and F), 250 nm (H and I), 100 nm (B, C, E and G).

Mentions: Because the Kir3.2 subunit forms homomeric channels and seems to be an essential component of heteromeric Kir3 channels (Liao et al., 1996), we performed SDS-FRL of this subunit and addressed whether and how its dendritic density changes as a function of distance from the soma. High-resolution EM images revealed only very few gold particles for the Kir3.2 subunit on the P-face membranes (epitope 374–414 is cytoplasmic) of somata and proximal apical dendrites (Fig. 7A–C). In comparison, more gold particles were observed on apical dendrites in distal SR and SLM (Fig. 7D–G). In SR, spiny oblique dendrites and dendritic spines were also moderately labelled (Fig. 7H and I).


Distinct axo-somato-dendritic distributions of three potassium channels in CA1 hippocampal pyramidal cells.

Kirizs T, Kerti-Szigeti K, Lorincz A, Nusser Z - Eur. J. Neurosci. (2014)

Somato-dendritic distribution of the Kir3.2 subunit in CA1 PCs. (A) A low-magnification image of a CA1 PC soma with an emerging apical dendrite (Ap.Dendr) labelled for the Kir3.2 subunit (10-nm gold). (B and C) Higher magnification images of the boxed areas shown in panel A. (D) A spiny apical dendrite from the distal (dist.) part of SR is shown. (E) A higher magnification image of the boxed area shown in D. (F) A low-magnification image of a spiny tuft dendrite (Tuft Dendr.) in the SLM labelled for the Kir3.2 subunit (10 nm gold). (G) A higher magnification image of the boxed area shown in F. (H and I) Gold particles for the Kir3.2 subunit are associated with the P-faces of spiny oblique dendrites (Obl.Dendr.) in the proximal (H) and distal (I) parts of SR. (J) Bar graphs demonstrate the densities (mean ± SD) of gold particles in different subcellular compartments of CA1 PCs. *Values that are significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P < 0.01; n = 3 rats). The inset shows that gold particle density in the AIS was not significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P = 0.95; n = 3 rats). The AISs were identified based on their immunopositivity for pan-NF. BG, background; mid., middle; Sp, spine; AxTerm, axon terminal. Scale bars, 1 μm (A), 500 nm (D and F), 250 nm (H and I), 100 nm (B, C, E and G).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150533&req=5

fig07: Somato-dendritic distribution of the Kir3.2 subunit in CA1 PCs. (A) A low-magnification image of a CA1 PC soma with an emerging apical dendrite (Ap.Dendr) labelled for the Kir3.2 subunit (10-nm gold). (B and C) Higher magnification images of the boxed areas shown in panel A. (D) A spiny apical dendrite from the distal (dist.) part of SR is shown. (E) A higher magnification image of the boxed area shown in D. (F) A low-magnification image of a spiny tuft dendrite (Tuft Dendr.) in the SLM labelled for the Kir3.2 subunit (10 nm gold). (G) A higher magnification image of the boxed area shown in F. (H and I) Gold particles for the Kir3.2 subunit are associated with the P-faces of spiny oblique dendrites (Obl.Dendr.) in the proximal (H) and distal (I) parts of SR. (J) Bar graphs demonstrate the densities (mean ± SD) of gold particles in different subcellular compartments of CA1 PCs. *Values that are significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P < 0.01; n = 3 rats). The inset shows that gold particle density in the AIS was not significantly different from the background labelling (anova, P < 0.001; Dunnett's post hoc test, P = 0.95; n = 3 rats). The AISs were identified based on their immunopositivity for pan-NF. BG, background; mid., middle; Sp, spine; AxTerm, axon terminal. Scale bars, 1 μm (A), 500 nm (D and F), 250 nm (H and I), 100 nm (B, C, E and G).
Mentions: Because the Kir3.2 subunit forms homomeric channels and seems to be an essential component of heteromeric Kir3 channels (Liao et al., 1996), we performed SDS-FRL of this subunit and addressed whether and how its dendritic density changes as a function of distance from the soma. High-resolution EM images revealed only very few gold particles for the Kir3.2 subunit on the P-face membranes (epitope 374–414 is cytoplasmic) of somata and proximal apical dendrites (Fig. 7A–C). In comparison, more gold particles were observed on apical dendrites in distal SR and SLM (Fig. 7D–G). In SR, spiny oblique dendrites and dendritic spines were also moderately labelled (Fig. 7H and I).

Bottom Line: The Kv2.1 subunit was found in somatic, proximal dendritic and AIS plasma membranes at approximately the same densities.A quasi-linear increase in the Kir3.2 subunit density along the dendrites of PCs was detected, showing no significant difference between apical dendritic shafts, oblique dendrites or dendritic spines at the same distance from the soma.Our results demonstrate that each subunit has a unique cell-surface distribution pattern, and predict their differential involvement in synaptic integration and output generation at distinct subcellular compartments.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony Street 43, Budapest, Hungary.

Show MeSH
Related in: MedlinePlus