{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n Galanin receptor 1 (GALR1) is a widely expressed G protein–coupled receptor that plays diverse roles in both the central nervous system and peripheral tissues. In the brain, GALR1 signaling is neuroprotective and exerts anticonvulsant effects; mice lacking GALR1 display spontaneous tonic–clonic seizures and heightened seizure severity."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": " Moreover, genetic deletion studies have demonstrated that loss of GALR1 leads to increased anxiety‐like behaviors and selective impairments in aversive trace fear conditioning, highlighting its role in the modulation of emotional memory and stress."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n \n "}, {"type": "p", "children": [{"type": "t", "text": "\n In models of nociception, GALR1 functions as an inhibitory modulator; mice deficient in GALR1 exhibit enhanced pain sensitivity and prolonged pain‐like behaviors following nerve injury."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "5"}]}, {"type": "t", "text": " In the realm of oncology, GALR1 appears to act as a tumor suppressor in epithelial cancers such as head and neck squamous cell carcinoma. Loss of GALR1 expression—often through promoter hypermethylation—correlates with increased cell proliferation, chemoresistance, and poorer clinical outcomes."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "7", "end_ref": "10"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n \n "}, {"type": "p", "children": [{"type": "t", "text": "\n GALR1 also contributes to metabolic regulation. Deficiency in GALR1 impairs the normal adaptation to high–fat diet challenges and disrupts glucose homeostasis"}, {"type": "fg", "children": [{"type": "fg_f", "ref": "11"}]}, {"type": "t", "text": ", and its expression is up–regulated in adipose tissues under high–fat feeding conditions."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "12"}]}, {"type": "t", "text": " In the gastrointestinal system, activation of GALR1 potently inhibits the secretion of incretin hormones (GLP–1 and GIP), thereby affecting gut hormone release."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "13"}]}, {"type": "t", "text": " Additionally, the ability of GALR1 to form heteromers with 5–HT1A receptors suggests an allosteric modulatory function in serotonergic signaling that may be relevant to mood regulation."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "14"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n \n "}, {"type": "p", "children": [{"type": "t", "text": "\n Finally, GALR1 expression is subject to dynamic regulation; altered levels of endogenous galanin can induce compensatory changes in GALR1 mRNA via cAMP–dependent mechanisms."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "15"}]}, {"type": "t", "text": " Collectively, these findings underscore GALR1’s multifaceted role in neuroprotection, emotional and pain regulation, metabolic homeostasis, and tumor suppression, thereby highlighting its potential as a therapeutic target in neurological, metabolic, and oncological disorders.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Arie Steven Jacoby, Yvonne Janet Hort, George Constantinescu, et al. 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