1. Shimizu H. Narrative reconstruction of mental illness as a work-stress-induced disorder: processes, consequences and implications. Sociol Health Illness. 2021;43(5):1206e1220.
2. Deonaraine KK, Wang Q, Cheng H, et al. Sex-specific peripheral and central responses to stress-induced depression and treatment in a mouse model. J Neurosci Res. 2020;98(12):2541e2553.
3. Yang H, Drummer TD, Carter JR. Sex differences in sympathetic neural and limb vascular reactivity to mental stress in humans. Am J Physiol Heart Circ Physiol. 2013;304(3):H436eH443.
4. Veldhuijzen van Zanten JJ, Ring C, Burns VE, Edwards KM, Drayson M, Carroll D. Mental stress-induced hemoconcentration: sex differences and mechanisms. Psychophysiology. 2004;41(4):541e551.
5. Chen Y, Dangardt F, Osika W, Berggren K, Gronowitz E, Friberg P. Age- and sex- related differences in vascular function and vascular response to mental stress: longitudinal and cross-sectional studies in a cohort of healthy children and adolescents. Atherosclerosis. 2012;220(1):269e274.
6. Sora I. Opioid receptor knockout mice. Nihon Shinkei Seishin Yakurigaku Zasshi. 1999;19(5):239e249.
7. Varlinskaya EI, Spear LP, Diaz MR. Stress alters social behavior and sensitivity to pharmacological activation of kappa opioid receptors in an age-specific manner in Sprague Dawley rats. Neurobiol Stress. 2018;9:124e132.
8. Wu S, Wong MC, Chen M, Cho CH, Wong TM. Role of opioid receptors in car- dioprotection of cold-restraint stress and morphine. J Biomed Sci. 2004;11(6): 726e731.
9. Sugiyama A, Yamada M, Furuie H, et al. Systemic administration of a delta opioid receptor agonist, KNT-127, facilitates extinction learning of fear memory in rats. J Pharmacol Sci. 2019;139(3):174e179.
10. Ide S, Sora I, Ikeda K, Minami M, Uhl GR, Ishihara K. Reduced emotional and corticosterone responses to stress in m-opioid receptor knockout mice. Neuropharmacology. 2010;58(1):241e247.
11. Komatsu H, Ohara A, Sasaki K, et al. Decreased response to social defeat stress in m-opioid-receptor knockout mice. Pharmacol Biochem Behav. 2011;99(4): 676e682.
12. Pierre F, Ugur M, Faivre F, Doridot S, Veinante P, Massotte D. Morphine- dependent and abstinent mice are characterized by a broader distribution of the neurons co-expressing mu and delta opioid receptors. Neuropharmacology. 2019;152:30e41.
13. Jozwiak K, Plazinska A. Structural insights into ligand-receptor interactions involved in biased agonism of G-protein coupled receptors. Molecules. 2021;26(4):851.
14. Nagase H, Saitoh A. Research and development of k opioid receptor agonists and d opioid receptor agonists. Pharmacol Ther. 2020;205, 107427.
15. Negus SS, Butelman ER, Chang KJ, DeCosta B, Winger G, Woods JH. Behavioral effects of the systemically active delta opioid agonist BW373U86 in rhesus monkeys. J Pharmacol Exp Therapeut. 1994;270(3):1025e1034.
16. Saitoh A, Kimura Y, Suzuki T, Kawai K, Nagase H, Kamei J. Potential anxiolytic and antidepressant-like activities of SNC80, a selective d-opioid agonist, in behavioral models in rodents. J Pharmacol Sci. 2004;95(3):374e380.
17. Perrine SA, Hoshaw BA, Unterwald EM. Delta opioid receptor ligands modulate anxiety-like behaviors in the rat. Br J Pharmacol. 2006;147(8):864e872.
18. Filliol D, Ghozland S, Chluba J, et al. Mice deficient for d- and m-opioid receptors exhibit opposing alterations of emotional responses. Nat Genet. 2000;25(2): 195e200.
19. Broom DC, Jutkiewicz EM, Rice KC, Traynor JR, Woods JH. Behavioral effects of d-opioid receptor agonists: potential antidepressants? Jpn J Pharmacol. 2002;90(1):1e6.
20. Matthes HW, Smadja C, Valverde O, et al. Activity of the d-opioid receptor is partially reduced, whereas activity of the k-receptor is maintained in mice lacking the m-receptor. J Neurosci. 1998;18(18):7285e7295.
21. Nagase H, Nemoto T, Matsubara A, et al. Design and synthesis of KNT-127, a d- opioid receptor agonist effective by systemic administration. Bioorg Med Chem Lett. 2010;20(21):6302e6305.
22. Sakamoto K, Yamada D, Yamanaka N, et al. A selective delta opioid receptor agonist SNC80, but not KNT-127, induced tremor-like behaviors via hippo- campal glutamatergic system in mice. Brain Res. 2021;1757, 147297.
23. Yamada D, Takahashi J, Iio K, Nagase H, Saitoh A. Modulation of glutamatergic synaptic transmission and neuronal excitability in the prelimbic medial pre- frontal cortex via delta-opioid receptors in mice. Biochem Biophys Res Commun. 2021;560:192e198.
24. Saitoh A, Suzuki S, Soda A, et al. The delta opioid receptor agonist KNT-127 in the prelimbic medial prefrontal cortex attenuates veratrine-induced anxiety- like behaviors in mice. Behav Brain Res. 2018;336:77e84.
25. Rozenfeld R, Devi LA. Receptor heterodimerization leads to a switch in signaling: b-arrestin2-mediated ERK activation by m-d opioid receptor heter- odimers. Faseb J. 2007;21(10):2455e2465.
26. Costantino CM, Gomes I, Stockton SD, Lim MP, Devi LA. Opioid receptor het- eromers in analgesia. Expet Rev Mol Med. 2012;14:e9.
27. Erbs E, Faget L, Scherrer G, et al. A mu-delta opioid receptor brain atlas reveals neuronal co-occurrence in subcortical networks. Brain Struct Funct. 2015;220(2):677e702.
28. Nobile B, Ramoz N, Jaussent I, et al. Polymorphism A118G of opioid receptor mu 1 (OPRM1) is associated with emergence of suicidal ideation at antide- pressant onset in a large naturalistic cohort of depressed outpatients. Sci Rep. 2019;9(1):2569.
29. Sora I, Takahashi N, Funada M, et al. Opiate receptor knockout mice define m receptor roles in endogenous nociceptive responses and morphine-induced analgesia. Proc Natl Acad Sci U S A. 1997;94(4):1544e1549.
30. Saitoh A, Sugiyama A, Nemoto T, et al. The novel d opioid receptor agonist KNT-127 produces antidepressant-like and antinociceptive effects in mice without producing convulsions. Behav Brain Res. 2011;223(2):271e279.
31. Chatterjee M, Jaiswal M, Palit G. Comparative evaluation of forced swim test and tail suspension test as models of negative symptom of schizophrenia in rodents. ISRN Psychiatry. 2012;2012, 595141.
32. Sakamoto K, Okahashi T, Matsumura S, et al. The opioid system majorly con- tributes to preference for fat emulsions but not sucrose solutions in mice. Biosci Biotechnol Biochem. 2015;79(4):658e663.
33. Zhang M, Kelley AE. Opiate agonists microinjected into the nucleus accumbens enhance sucrose drinking in rats. Psychopharmacology. 1997;132(4):350e360.
34. Glass MJ, Grace MK, Cleary JP, Billington CJ, Levine AS. Naloxone's effect on meal microstructure of sucrose and cornstarch diets. Am J Physiol Regul Integr Comp Physiol. 2001;281(5):R1605eR1612.
35. Ostlund SB, Kosheleff A, Maidment NT, Murphy NP. Decreased consumption of sweet fluids in m opioid receptor knockout mice: a microstructural analysis of licking behavior. Psychopharmacology. 2013;229(1):105e113.
36. Papaleo F, Kieffer BL, Tabarin A, Contarino A. Decreased motivation to eat in m- opioid receptor-deficient mice. Eur J Neurosci. 2007;25(11):3398e3405.
37. Saitoh A, Soda A, Kayashima S, et al. A delta opioid receptor agonist, KNT-127, in the prelimbic medial prefrontal cortex attenuates glial glutamate trans- porter blocker-induced anxiety-like behavior in mice. J Pharmacol Sci. 2018;138(3):176e183.
38. Sugiyama A, Yamada M, Saitoh A, Nagase H, Oka JI, Yamada M. Administration of a delta opioid receptor agonist KNT-127 to the basolateral amygdala has robust anxiolytic-like effects in rats. Psychopharmacology. 2018;235(10): 2947e2955.
39. Fujii H, Uchida Y, Shibasaki M, et al. Discovery of d opioid receptor full agonists lacking a basic nitrogen atom and their antidepressant-like effects. Bioorg Med Chem Lett. 2020;30(12), 127176.
40. Nozaki C, Nagase H, Nemoto T, Matifas A, Kieffer BL, Gaveriaux-Ruff C. In vivo properties of KNT-127, a novel d opioid receptor agonist: receptor internali- zation, antihyperalgesia and antidepressant effects in mice. Br J Pharmacol. 2014;171(23):5376e5386.
41. Fichna J, Janecka A, Piestrzeniewicz M, Costentin J, do Rego JC. Antidepressant- like effect of endomorphin-1 and endomorphin-2 in mice. Neuro- psychopharmacology. 2007;32(4):813e821.
42. Suzuki T, Tsuji M, Mori T, Misawa M, Endoh T, Nagase H. Effects of a highly selective nonpeptide d opioid receptor agonist, TAN-67, on morphine-induced antinociception in mice. Life Sci. 1995;57(2):155e168.
43. Sugiyama A, Nagase H, Oka J, Yamada M, Saitoh A. DOR2-selective but not DOR1-selective antagonist abolishes anxiolytic-like effects of the d opioid re- ceptor agonist KNT-127. Neuropharmacology. 2014;79:314e320.
44. Hall FS, Goeb M, Li XF, Sora I, Uhl GR. m-Opioid receptor knockout mice display reduced cocaine conditioned place preference but enhanced sensitization of cocaine-induced locomotion. Brain Res Mol Brain Res. 2004;121(1-2):123e130.
45. Moriya Y, Kasahara Y, Hall FS, et al. Sex differences in the effects of adolescent social deprivation on alcohol consumption in m-opioid receptor knockout mice. Psychopharmacology. 2015;232(8):1471e1482.
46. Fujita W, Gomes I, Devi LA. Heteromers of m-d opioid receptors: new pharma- cology and novel therapeutic possibilities. Br J Pharmacol. 2015;172(2):375e387.
47. Martinez-Navarro M, Cabanero D, Wawrzczak-Bargiela A, et al. Mu and delta opioid receptors play opposite nociceptive and behavioural roles on nerve- injured mice. Br J Pharmacol. 2020;177(5):1187e1205.
48. Rosenblum A, Marsch LA, Joseph H, Portenoy RK. Opioids and the treatment of chronic pain: controversies, current status, and future directions. Exp Clin Psychopharmacol. 2008;16(5):405e416.
49. Cooper ZD, Truong YN, Shi YG, Woods JH. Morphine deprivation increases self- administration of the fast- and short-acting m-opioid receptor agonist remi- fentanil in the rat. J Pharmacol Exp Therapeut. 2008;326(3):920e929.
50. Inturrisi CE. Clinical pharmacology of opioids for pain. Clin J Pain. 2002;18(4): S3eS13.
51. Meier IM, van Honk J, Bos PA, Terburg D. A mu-opioid feedback model of human social behavior. Neurosci Biobehav Rev. 2021;121:250e258.
52. Sora I, Li XF, Funada M, Kinsey S, Uhl GR. Visceral chemical nociception in mice lacking m-opioid receptors: effects of morphine, SNC80 and U-50,488. Eur J Pharmacol. 1999;366(2-3):R3eR5.
53. Bilsky EJ, Calderon SN, Wang T, et al. SNC 80, a selective, nonpeptidic and systemically active opioid delta agonist. J Pharmacol Exp Therapeut. 1995;273(1):359e366.
54. Nagase H, Kawai K, Hayakawa J, et al. Rational drug design and synthesis of a highly selective nonpeptide delta-opioid agonist, (4aS*,12aR*)-4a-(3- hydroxyphenyl)-2-methyl- 1,2,3,4,4a,5,12,12a-octahydropyrido[3,4-b]acridine (TAN-67). Chem Pharm Bull. 1998;46(11):1695e1702.
55. Saitoh A, Sugiyama A, Yamada M, et al. The novel d opioid receptor agonist KNT-127 produces distinct anxiolytic-like effects in rats without producing the adverse effects associated with benzodiazepines. Neuropharmacology. 2013;67: 485e493.
56. Finn DA, Helms ML, Nipper MA, Cohen A, Jensen JP, Devaud LL. Sex differences in the synergistic effect of prior binge drinking and traumatic stress on sub- sequent ethanol intake and neurochemical responses in adult C57BL/6J mice. Alcohol. 2018;71:33e45.
57. Chalangal J, Mazid S, Windisch K, Milner TA. Sex differences in the rodent hippocampal opioid system following stress and oxycodone associated learning processes. Pharmacol Biochem Behav. 2022;212, 173294.
58. Galligan JJ, Sternini C. Insights into the role of opioid receptors in the GI tract: experimental evidence and therapeutic relevance. Handb Exp Pharmacol. 2017;239:363e378.
59. Hayashi T, Yasueda Y, Tamura T, Takaoka Y, Hamachi I. Analysis of cell-surface receptor dynamics through covalent labeling by catalyst-tethered antibody. J Am Chem Soc. 2015;137(16):5372e5380.