Ucn

Spatial tier: STRICT_EXCLUSIVE · Class: OTHER · Top region: RL (Rostral linear nucleus raphe) · Positive regions: 7/554

50.6Discovery Score
39.6Targetability Score
CEvidence grade C
What this means: Ucn: predicted fine-region profile is strict-exclusive, with 7 positive regions out of 554 (limit 12); direct spatial validation is required.

Function in RL: evidence, prediction, innovation

Gene function
Ucn encodes urocortin-1, a 40-amino-acid corticotropin-releasing-factor-family neuropeptide. It activates CRF1 and, with far higher affinity than CRF, CRF2, via Gs/cAMP. Urocortin-1 mediates stress coping, anxiety, satiety and alcohol-related behaviours, plus peripheral cardiovascular actions.
Region function
The rostral linear nucleus is a midline midbrain raphe-complex nucleus of intermixed dopaminergic (A10 extension), serotonergic and GABAergic neurons serving reward, opiate reinforcement and motivation.
Published in this region
expression only Rodent brain's densest urocortin-1 group, the centrally projecting Edinger-Westphal nucleus (EWcp/pIIIu) in ventromedial periaqueductal grey, partly overlaps the CCF territory annotated RL, so the RL signal likely reports it. EWcp Ucn1 is required for ethanol preference (Giardino et al. 2011), responds to leptin (Xu et al. 2011) and projects to lateral septum (Bachtell et al. 2003); caudal dorsal raphe Ucn1 alters food and fluid intake (Weitemier et al. 2006).
Predicted function
Prediction: Ucn cells at the RL/EWcp border form a CRF2-biased stress-and-satiety node releasing urocortin-1 onto dorsal raphe, lateral septum and VTA. Chemogenetic activation should suppress feeding and ethanol intake; Ucn deletion or local astressin2-B should blunt binge drinking and stress-induced hypophagia.
Innovation
★★☆☆☆ 2/5 Urocortin-1 is heavily studied but always as EWcp, so novelty lies in re-registering it to RL and testing dopaminergic neighbours.
Tools
Ucn knockout mice; Ucn1 antisera; CRF2 antagonist astressin2-B, CRF1 antagonist antalarmin; Cart-Cre for EWcp, where AAV targeting is established; Th-Cre, Dat-Cre, Slc6a4-Cre label neighbouring RL cells.
References

Direct evidence located at the region

Ucn Allen ISH at the CCF centroid of RL

Allen ISH experiment 1435, section image 101316996 (section 175): the section that contains the CCF centroid of Rostral linear nucleus raphe 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 UcnAllen reference atlas: RL (structure 197)ABC Atlas MERFISH viewer(in the ABC Atlas choose dataset MERFISH-C57BL6J-638850-CCF, colour cells by gene "Ucn" or by parcellation_substructure "RL")All genes confined to RL + 3-D brain

Direct spatial evidence

MERFISH REGION LOCATOR
RL MERFISH region locator
Real single-cell MERFISH coordinates for the RL (Rostral linear nucleus raphe) 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

Ucn regional expression profile

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

Spatial profile

RL
0.84
XII
0.35
EW
0.337
PIR
0.308
DMX
0.274
V
0.243
VII
0.209
PAA
0.178
VISpor4
0.171
AIp2/3
0.165
VISC2/3
0.158
VISC4
0.157
TEa4
0.156
AUDv2/3
0.146
TEa2/3
0.139
VISli4
0.129
AUDv4
0.126
AIp5
0.126
AUDpo4
0.124
AIv2/3
0.121

Evidence and specificity

Evidence status
PREDICTED_FINE
Direct sources
None; predicted localization only
Exclusive threshold
12 positive regions out of 554
Spatial specificity
0.357
Top-region fraction
0.116
Filter status
PASS

Interpretation limits