Velusetrag (TD-5108) is an orally active, potent and selective agonist of serotonin 5-HT 4 receptor (5-HT4R) , with a pK i of 7.7. Velusetrag exhibits no affinity (K i >10 μM) for 5-HT 2A and 5-HT 2B receptors. Velusetrag can be used for the research of gastrointestinal diseases and Parkinson's disease In Vitro Velusetrag (10 pM-100 μM) concentration-dependently increases the cAMP in HEK-293 cells stably transfected with the h5-HT4(c) receptor, with a pEC 50 of 8.3. Velusetrag (100 pM-1 μM) produces concentration-dependent contraction of the guinea pig colonic longitudinal muscle/myenteric plexus (LMMP), with a pEC 50 of 7.9. Velusetrag (0.001-10 μM) produces a concentration-dependent relaxation of the carbachol (3 μM)-precontracted rat esophagus, with a pEC 50 of 7.9. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Velusetrag (3 mg/kg; a single i.p.) significantly improves the facilitation of contextual fear extinction in PD mice. Velusetrag (3 mg/kg; a single i.p.) increases hippocampal cAMP levels in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice. Velusetrag (0.003-3 mg/kg; a single s.c.) increases colonic transit in a dose-dependent manner and reduces the time taken for excretion of the dye in guinea pigs. Velusetrag (0.003-1 mg/kg; a single i.v.) dose-dependently increases inter-crystal distance, consistent with relaxation of the oesophagus in rats. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Male C57BL/6 mice (7-8 weeks old) were injected with MPTPDosage: 3 mg/kg Administration: A single i.p. Result: Improved facilitation of contextual fear extinction. Did not improve the impaired rotarod performance in PD mice. Form:Solid IC50& Target:5-HT 4 Receptor 7.7 (pKi)