TY - JOUR

T1 - Altered behaviour, dopamine and norepinephrine regulation in stressed mice heterozygous in TPH2 gene

AU - Strekalova, Tatyana

AU - Svirin, Evgeniy

AU - Waider, Jonas

AU - Gorlova, Anna

AU - Cespuglio, Raymond

AU - Kalueff, Allan

AU - Pomytkin, Igor

AU - Schmitt-Boehrer, Angelika G.

AU - Lesch, Klaus Peter

AU - Anthony, Daniel C.

N1 - Funding Information: The authors' work reported here was supported by Deutsche Forschungsgemeinschaft (DFG:CRC TRR58A1/A5), DAAD (to ES), the European Union's Seventh Framework Programme (FP7/2007–2013) under Grant No.602805 (Aggressotype) and the Horizon 2020 Research and Innovation Programme under Grant No.728018 (Eat2beNICE) (to KPL and TS) and the President's program of PhD Exchange of RF-2017 (to TS and DA). We appreciate the valuable technical help of Natalia Bazhenova, Drs. Alexander Trofimov and Natalia Markova with this project. Publisher Copyright: © 2020 The Authors Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020

Y1 - 2020

N2 - Gene-environment interaction (GxE) determines the vulnerability of an individual to a spectrum of stress-related neuropsychiatric disorders. Increased impulsivity, excessive aggression, and other behavioural characteristics are associated with variants within the tryptophan hydroxylase-2 (Tph2) gene, a key enzyme in brain serotonin synthesis. This phenotype is recapitulated in naïve mice with complete, but not with partial Tph2 inactivation. Tph2 haploinsufficiency in animals reflects allelic variation of Tph2 facilitating the elucidation of respective GxE mechanisms. Recently, we showed excessive aggression and altered serotonin brain metabolism in heterozygous Tph2-deficient male mice (Tph2+/−) after predator stress exposure. Here, we sought to extend these studies by investigating aggressive and anxiety-like behaviours, sociability, and the brain metabolism of dopamine and noradrenaline. Separately, Tph2+/− mice were examined for exploration activity in a novel environment and for the potentiation of helplessness in the modified swim test (ModFST). Predation stress procedure increased measures of aggression, dominancy, and suppressed sociability in Tph2+/− mice, which was the opposite of that observed in control mice. Anxiety-like behaviour was unaltered in the mutants and elevated in controls. Tph2+/− mice exposed to environmental novelty or to the ModFST exhibited increased novelty exploration and no increase in floating behaviour compared to controls, which is suggestive of resilience to stress and despair. High-performance liquid chromatography (HPLC) revealed significant genotype-dependent differences in the metabolism of dopamine, and norepinephrine within the brain tissue. In conclusion, environmentally challenged Tph2+/− mice exhibit behaviours that resemble the behaviour of non-stressed null mutants, which reveals how GxE interaction studies can unmask latent genetically determined predispositions.

AB - Gene-environment interaction (GxE) determines the vulnerability of an individual to a spectrum of stress-related neuropsychiatric disorders. Increased impulsivity, excessive aggression, and other behavioural characteristics are associated with variants within the tryptophan hydroxylase-2 (Tph2) gene, a key enzyme in brain serotonin synthesis. This phenotype is recapitulated in naïve mice with complete, but not with partial Tph2 inactivation. Tph2 haploinsufficiency in animals reflects allelic variation of Tph2 facilitating the elucidation of respective GxE mechanisms. Recently, we showed excessive aggression and altered serotonin brain metabolism in heterozygous Tph2-deficient male mice (Tph2+/−) after predator stress exposure. Here, we sought to extend these studies by investigating aggressive and anxiety-like behaviours, sociability, and the brain metabolism of dopamine and noradrenaline. Separately, Tph2+/− mice were examined for exploration activity in a novel environment and for the potentiation of helplessness in the modified swim test (ModFST). Predation stress procedure increased measures of aggression, dominancy, and suppressed sociability in Tph2+/− mice, which was the opposite of that observed in control mice. Anxiety-like behaviour was unaltered in the mutants and elevated in controls. Tph2+/− mice exposed to environmental novelty or to the ModFST exhibited increased novelty exploration and no increase in floating behaviour compared to controls, which is suggestive of resilience to stress and despair. High-performance liquid chromatography (HPLC) revealed significant genotype-dependent differences in the metabolism of dopamine, and norepinephrine within the brain tissue. In conclusion, environmentally challenged Tph2+/− mice exhibit behaviours that resemble the behaviour of non-stressed null mutants, which reveals how GxE interaction studies can unmask latent genetically determined predispositions.

KW - Aggression

KW - Dopamine

KW - Mouse

KW - Noradrenaline

KW - Stress

KW - Tryptophan hydroxylase-2 (Tph2)

UR - http://www.scopus.com/inward/record.url?scp=85095992892&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/882a4dda-d418-3f76-a020-49603b40f451/

U2 - 10.1016/j.pnpbp.2020.110155

DO - 10.1016/j.pnpbp.2020.110155

M3 - Article

C2 - 33127424

AN - SCOPUS:85095992892

JO - Progress in Neuro-Psychopharmacology and Biological Psychiatry

JF - Progress in Neuro-Psychopharmacology and Biological Psychiatry

SN - 0278-5846

M1 - 110155

ER -