Tbxa2r

Thromboxane A2 receptor (TXA2-R) (Prostanoid TP receptor)

Spatial tier: REGION_BIASED · Class: GPCR · Top region: MMd (Medial mammillary nucleus, dorsal part) · Positive regions: 44/554

43.5Discovery Score
35.1Targetability Score
CEvidence grade C
What this means: Tbxa2r: fine CCF profile is region-biased toward MMd (top regions: MMd, AIp1, IG, AUDd1, LM); this is a discovery lead, not direct proof.

Function in MMd: evidence, prediction, innovation

Gene function
TBXA2R (the TP receptor) is the GPCR for thromboxane A2 and related prostanoids, signalling mainly through Gq/PLC to raise intracellular calcium and through G12/13-RhoA to remodel the cytoskeleton. It is the canonical platelet-aggregation and vasoconstriction receptor, and is the target of drugs such as seratrodast and the antagonist SQ29548.
Region function
The medial mammillary nucleus is the hypothalamic node of the Papez/extended hippocampal circuit: it receives subicular input via the fornix and projects through the mammillothalamic tract to the anterior thalamic nuclei, supporting theta-paced spatial and episodic memory.
Published in this region
inferred No region-specific literature found. In other CNS tissue TP is functional on neurons and glia: Sumimoto 2015 showed the TP agonist U-46619 promotes neurite outgrowth in cortical neurons via MAPK, and Yang 2016 showed TP stimulation drives microglial IL-1beta and NO release after ischaemia.
Predicted function
Prediction: in the dorsal medial mammillary nucleus TP is most likely expressed on the dense local vasculature and perivascular/microglial cells rather than on projection neurons, where it would couple prostanoid signalling to local blood flow and inflammatory tone in a nucleus that is highly vulnerable to thiamine deficiency and hypoxia. If neuronal, Gq signalling would depolarise mammillary cells and enhance burst firing. TP antagonism (SQ29548, seratrodast) should blunt inflammation-driven mammillary damage in Wernicke-Korsakoff-like thiamine-deficiency models.
Innovation
★★★★☆ 4/5 Prostanoid signalling is essentially unexplored in mammillary neurons even though this nucleus is the signature lesion site of Korsakoff syndrome.
Tools
Antagonists SQ29548, seratrodast and ramatroban; agonist U-46619; Tbxa2r knockout mice; validated anti-TP antibodies.
References

Direct evidence located at the region

Tbxa2r Allen ISH at the CCF centroid of MMd

Allen ISH experiment 69288363, section image 69245470 (section 145): the section that contains the CCF centroid of Medial mammillary nucleus, dorsal part 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 Tbxa2rAllen reference atlas: MMd (structure 606826659)ABC Atlas MERFISH viewer(in the ABC Atlas choose dataset MERFISH-C57BL6J-638850-CCF, colour cells by gene "Tbxa2r" or by parcellation_substructure "MMd")All genes confined to MMd + 3-D brain

Direct spatial evidence

MERFISH REGION LOCATOR
MMd MERFISH region locator
Real single-cell MERFISH coordinates for the MMd (Medial mammillary nucleus, dorsal part) 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

Tbxa2r regional expression profile

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

Spatial profile

MMd
0.489
AIp1
0.35
IG
0.344
AUDd1
0.334
LM
0.332
MH
0.328
ORBvl1
0.328
SSp-m1
0.324
AId1
0.324
AUDpo1
0.318
VISrl1
0.317
AUDv1
0.317
ECT1
0.317
SSp-n1
0.311
NLOT1
0.298
GU1
0.297
SSs1
0.295
AIv1
0.294
VISl1
0.29
ACAd1
0.289

Evidence and specificity

Evidence status
PREDICTED_FINE
Direct sources
None; predicted localization only
Exclusive threshold
12 positive regions out of 554
Spatial specificity
0.286
Top-region fraction
0.047
Filter status
PASS

Interpretation limits