Scnn1g

Epithelial sodium channel subunit gamma (Epithelial Na(+) channel subunit gamma) (Gamma-ENaC) (Amiloride-sensitive sodium channel subunit gamma) (Gamma-NaCH) (Nonvoltage-gated sodium channel 1 subunit

Spatial tier: REGION_BIASED · Class: ION_CHANNEL · Top region: POST (Postsubiculum) · Positive regions: 29/554

48.0Discovery Score
36.5Targetability Score
CEvidence grade C
What this means: Scnn1g: fine CCF profile is region-biased toward POST (top regions: POST, PRE, FOTU, PRM, RSPv2/3); this is a discovery lead, not direct proof.

Function in POST: evidence, prediction, innovation

Gene function
SCNN1G encodes the gamma subunit of the epithelial sodium channel (ENaC), a constitutively open, amiloride-sensitive, voltage-independent sodium channel assembled from alpha, beta and gamma subunits. In kidney and airway epithelium it mediates hormone-regulated sodium reabsorption; gain-of-function mutations cause Liddle syndrome. ENaC subunits also act as mechanosensitive and sodium-sensing elements in some non-epithelial cells.
Region function
The postsubiculum (dorsal presubiculum) is the principal cortical head-direction area: its neurons fire as a function of allocentric heading, receive anterodorsal thalamic and visual input, and anchor the head-direction signal to visual landmarks for navigation.
Published in this region
none No region-specific literature found. The closest related finding is that head-direction coding in postsubiculum depends on intrinsic conductances that set persistent firing and sleep-related sequences (Mehrotra 2024), while ENaC subunits themselves have only been characterised functionally in epithelia, vasculature and a few magnocellular/circumventricular neurons.
Predicted function
Prediction: a constitutively open sodium leak channel in postsubicular neurons would contribute standing depolarisation and thereby support the persistent, direction-tuned firing that head-direction cells must sustain for seconds at a time. Blocking it locally with amiloride/benzamil or deleting Scnn1g should hyperpolarise postsubicular neurons, lower baseline and peak head-direction firing rates and broaden directional tuning, predicting less stable heading and impaired landmark-anchored navigation, with little effect on place-cell fields downstream.
Innovation
★★★★★ 5/5 A leak sodium channel as a substrate for persistent head-direction firing is a testable idea nobody has pursued in postsubiculum.
Tools
Amiloride and the more selective benzamil; Scnn1g floxed and Liddle-syndrome knock-in mouse lines; anti-gamma-ENaC antibodies; postsubicular targeting with standard stereotaxic AAV plus Camk2a-Cre or Vglut1-Cre.
References

Direct evidence located at the region

Scnn1g Allen ISH at the CCF centroid of POST

Allen ISH experiment 1918, section image 101364162 (section 143): the section that contains the CCF centroid of Postsubiculum according to the Allen image-to-atlas alignment (reference_to_image), with a 2 mm window around that point. Left: whole section, red box = window. Middle: ISH signal. Right: Allen's expression-mask view of the same window. open this image in the Allen viewer

Look it up yourself: Allen Mouse Brain ISH for Scnn1gAllen reference atlas: POST (structure 1037)ABC Atlas MERFISH viewer(in the ABC Atlas choose dataset MERFISH-C57BL6J-638850-CCF, colour cells by gene "Scnn1g" or by parcellation_substructure "POST")All genes confined to POST + 3-D brain

Direct spatial evidence

MERFISH REGION LOCATOR
POST MERFISH region locator
Real single-cell MERFISH coordinates for the POST (Postsubiculum) section -- our own ground-truth data, showing exactly where this region sits, independent of whether the Allen ISH section below is easy to read.

Regional expression figure

Scnn1g regional expression profile

Predicted WMB × fine-CCF profile; not direct full-transcriptome spatial measurement.

Spatial profile

POST
0.239
PRE
0.224
FOTU
0.216
PRM
0.2
RSPv2/3
0.197
PYR
0.197
ANcr2
0.174
ANcr1
0.168
DEC
0.167
SIM
0.15
LING
0.144
PG
0.141
PFL
0.139
CUL4, 5
0.134
x
0.129
CENT2
0.126
NOD
0.126
COPY
0.123
DCO
0.122
CENT3
0.122

Evidence and specificity

Evidence status
PREDICTED_FINE
Direct sources
None; predicted localization only
Exclusive threshold
12 positive regions out of 554
Spatial specificity
0.351
Top-region fraction
0.047
Filter status
PASS

Interpretation limits