| 1. |
- Ruggeri, Barbara, et al.
(författare)
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Methylation of OPRL1 mediates the effect of psychosocial stress on binge drinking in adolescents
- 2018
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Ingår i: Journal of Child Psychology and Psychiatry. - : Wiley. - 0021-9630 .- 1469-7610. ; 9:6, s. 50-658
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Nociceptin is a key regulator linking environmental stress and alcohol drinking. In a genome-wide methylation analysis, we recently identified an association of a methylated region in the OPRL1 gene with alcohol-use disorders.METHODS: Here, we investigate the biological basis of this observation by analysing psychosocial stressors, methylation of the OPRL1 gene, brain response during reward anticipation and alcohol drinking in 660 fourteen-year-old adolescents of the IMAGEN study. We validate our findings in marchigian sardinian (msP) alcohol-preferring rats that are genetically selected for increased alcohol drinking and stress sensitivity.RESULTS: We found that low methylation levels in intron 1 of OPRL1 are associated with higher psychosocial stress and higher frequency of binge drinking, an effect mediated by OPRL1 methylation. In individuals with low methylation of OPRL1, frequency of binge drinking is associated with stronger BOLD response in the ventral striatum during reward anticipation. In msP rats, we found that stress results in increased alcohol intake and decreased methylation of OPRL1 in the nucleus accumbens.CONCLUSIONS: Our findings describe an epigenetic mechanism that helps to explain how psychosocial stress influences risky alcohol consumption and reward processing, thus contributing to the elucidation of biological mechanisms underlying risk for substance abuse.
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| 2. |
- Henriksson, Johan, et al.
(författare)
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On the evaluation of quadratic response functions at the four-component Hartree-Fock level : Nonlinear polarization and two-photon absorption in bromo- and iodobenzene
- 2006
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 124:21
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Tidskriftsartikel (refereegranskat)abstract
- The nonlinear polarization and two-photon absorption parameters have been determined for dibromo- and di-iodobenzene in their meta- and ortho-conformations and with relativistic effects accounted for to a varying degree. By exclusion of small component integrals in the calculations of the first-order hyperpolarizability, results within 1% of fully relativistic four-component Hartree-Fock values are obtained at a cost of 8.7 times the corresponding nonrelativistic calculations. It is shown that the nonlinear absorption in bromobenzene (and even more so in iodobenzene) is broad banded due to spin-orbit interactions among the excited states, and nonrelativistic and scalar relativistic calculations are not to be used in this case. © 2006 American Institute of Physics.
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| 3. |
- Bast, R., et al.
(författare)
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Role of noncollinear magnetization for the first-order electric-dipole hyperpolarizability at the four-component Kohn-Sham density functional theory level
- 2009
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 130:2
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Tidskriftsartikel (refereegranskat)abstract
- The quadratic response function has been derived and implemented at the adiabatic four-component Kohn-Sham density functional theory level with inclusion of noncollinear spin magnetization and gradient corrections in the exchange-correlation functional-a work that is an extension of our previous report where magnetization dependencies in the exchange-correlation functional were ignored [J. Henriksson, T. Saue, and P. Norman, J. Chem. Phys. 128, 024105 (2008)]. The electric-field induced second-harmonic generation experiments on CF3 Cl and CF3 Br are addressed by a determination of Β- (-2ω;ω,ω) for a wavelength of 694.3 nm, and the same property is also determined for CF3 I. The relativistic effects on the static hyperpolarizability for the series of molecules amount to 1%, 5%, and 9%, respectively. At the experimental wavelength, the contributions to Β due to the magnetization dependence in the exchange-correlation functional are negligible for CF3 Cl and CF3 Br and small for CF 3 I. The noticeable effect of magnetization in the latter case is attributed to a near two-photon resonance with the excited state 1 E3 (nonrelativistic notation). It is emphasized, however, that the effect of magnetization on Β for CF3 I is negligible both in comparison to the total relativistic correction as well as to the effects of electron correlation. It is concluded that, in calculations of hyperpolarizabilities under nonresonant conditions, the magnetization dependence in the exchange-correlation functional may be ignored. © 2009 American Institute of Physics.
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