The Na+/Ca2+, K+ exchanger NCKX4 is required for efficient cone-mediated vision
- Washington University, United States
- Keck School of Medicine, University of Southern California, United States
- Johns Hopkins University, United States
Figures
Figure 1
NCKX4 is expressed in cone photoreceptors.
In situ hybridization with Nckx4 (Slc24a4) probe demonstrating sparse expression of NCKX4 in the photoreceptor layer of a WT mouse retina (a, arrows) and strong expression of NCKX4 in the …
Figure 2
NCKX4 is expressed in the outer segments of cone photoreceptors.
(a) Immunostaining for NCKX4 in vertical sections of mouse retinas (photoreceptors on the top). Nuclei (DNA, cyan), cone photoreceptors (PNA, red), and NCKX4 (green) staining in Cre-negative Nckx4+/+…
Figure 3
NCKX4 is broadly expressed in cones and in rod bipolar cells.
Immunostaining for NCKX4 (green) and short-wave opsin (S-opsin, red) in flat mounted retinas. In the dorsal region, S-opsin expressing cones were only a fraction of the NCKX4-expressing cones (a) …
Figure 4
NCKX4 accelerates light response termination and decreases the sensitivity of mouse cones.
(a) Slice preparation under infrared illumination. Photoreceptor outer segments are pointing to the right and the recording glass pipette is visible at the bottom right corner. Scale bar = 20 μm. …
Figure 5
NCKX4 accelerates cone light adaptation.
(a) A schematic of the system to record transretinal voltage (ex vivo ERG) from a superfused isolated mouse retina (pink, see Materials and methods for details). (b) Population averaged ex vivo cone …
Figure 6
NCKX4 extends the function of cones to brighter light.
The sensitivity to a flash of light (SF) for Nckx4+/f Cre+ control (a) and Nckx4f/f Cre+ (b) cones in background light was determined 2.5 s after the light step onset. Light step and flash timing …
Figure 7
NCKX4 extends the temporal resolution of cone-mediated vision to higher frequencies.
In vivo electroretinogram (ERG) responses to flickering light recorded from dark-adapted anesthetized Nckx4+/+ Cre+ (a) and Nckx4f/f Cre+ (b) mice. The frequency of the flicker stimulus (f) is …
Figure 8
Loss of both NCKX2 and NCKX4 expressions leads to alteration of outer segment structure and cone cell death.
Confocal stacked images from flat mounted retinas from 3-month-old Nckx2-/- mice (a, c, e) and their littermate Nckx2/4 double knockout animals (b, d, f) stained with antibodies against S-opsin (a, b…
Figure 9
Loss of both NCKX2 and NCKX4 expressions severely compromises cone function.
Representative light responses recorded from isolated retinas of Nckx4+/+ Cre+ (a), Nckx4f/f Cre+ (b) and Nckx2-/- Nckx4f/f Cre+ (c) mice using ex vivo ERG method. Light flashes ranged from 390 to …
Figure 10
NCKX4 is expressed in the outer segments of zebrafish and non-human primate cones.
Immunostaining of NCKX4 in the vertical sections of zebrafish (top) and macaque (bottom) retinas (photoreceptors on the top). Nuclei (DNA, cyan), cone photoreceptors (PNA, red), and NCKX4 (green) …
Tables
Table 1
Comparison of control and NCKX4-deficient cone flash response and light adaptation parameters. Rmax, maximal flash response amplitude (in pA) in single-cell recordings; tp, time from flash to the …
| Rmax (pA) | tp (ms) | τrec (ms) | Q1/2 (hv μm−2) | τ1 (ms) | τ2 (s) | I0 (hv μm−2 s−1) | Tint (ms) | |
|---|---|---|---|---|---|---|---|---|
| Nckx4+/+ Cre+ | 5.8 ± 1 | 76 ± 3 | 52 ± 8 | 1,150 ± 240 | 109 ± 27 | 1.3 ± 0.2 | 49,000 ± 11,000 | 80 ± 14 |
| Nckx4f/f Cre+ | 5.6 ± 0.4 | 121 ± 6* | 101 ± 13* | 670 ± 73* | 212 ± 37* | 1.5 ± 0.3 | 11,508 ± 990* | 160 ± 9* |
