{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T01:30:40Z","timestamp":1777858240674,"version":"3.51.4"},"reference-count":56,"publisher":"SAGE Publications","issue":"6","license":[{"start":{"date-parts":[[2020,4,27]],"date-time":"2020-04-27T00:00:00Z","timestamp":1587945600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"funder":[{"DOI":"10.13039\/501100002301","name":"eesti teadusagentuur","doi-asserted-by":"publisher","award":["PUT1686 and IUT20-40"],"award-info":[{"award-number":["PUT1686 and IUT20-40"]}],"id":[{"id":"10.13039\/501100002301","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["J Psychopharmacol"],"published-print":{"date-parts":[[2020,6]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Individual differences in behavioural traits influence susceptibility to addictive disorders. Drug addiction involves changes in gene expression, proposed to occur via DNA methylation (DNAm).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Aims:<\/jats:title>\n                    <jats:p>To investigate DNAm changes in reward-related brain structures (nucleus accumbens (NAc), lateral habenula (LHb)) in response to cocaine exposure in rats differing in spontaneous exploratory activity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>Rats were observed in the exploration box and categorised as high- (HE) or low explorers (LE). Rats were administered vehicle or cocaine (12\u2009mg\/kg, i.p.) for 7\u2009days, followed by a 14-day withdrawal period and cocaine challenge (7\u2009mg\/kg); horizontal locomotor activity was recorded. Brain tissue was dissected after 24\u2009h; we analysed messenger RNA (mRNA) and activity levels of epigenetic DNA modifiers (DNMTs and TETs) as well as mRNA and promoter methylation levels at selected genes previously linked to addictive behaviours.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      The cocaine challenge dose stimulated locomotor activity in both LE- and HE rats only when administered after a repeated cocaine schedule, suggesting development of behavioural sensitisation. Quantitative polymerase chain reaction analyses demonstrated higher basal expression of Dnmt3a, Tet2 and Tet3 in the LHb of HE- vs. LE rats, and we observed differential effects of cocaine exposure on the expression and activity of epigenetic DNA modifiers in the NAc and LHb of HE- and LE rats. Furthermore, cocaine exposure differentially altered promoter methylation levels of A\n                      <jats:sub>2A<\/jats:sub>\n                      R, Ppp1cc, and Taar7b in the NAc and LHb of HE- and LE rats.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions:<\/jats:title>\n                    <jats:p>DNAm might play a role in the HE- and LE phenotypes as well as mediate behavioural effects of LE- and HE rats in response to drugs of abuse.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/0269881120916137","type":"journal-article","created":{"date-parts":[[2020,4,27]],"date-time":"2020-04-27T06:14:55Z","timestamp":1587968095000},"page":"680-692","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":13,"title":["Cocaine-induced changes in behaviour and DNA methylation in rats are influenced by inter-individual differences in spontaneous exploratory activity"],"prefix":"10.1177","volume":"34","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0733-2505","authenticated-orcid":false,"given":"Kadi","family":"Vaher","sequence":"first","affiliation":[{"name":"Department of Psychology, University of Tartu, Tartu, Estonia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5039-4771","authenticated-orcid":false,"given":"Kaili","family":"Anier","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, University of Tartu, Tartu, Estonia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Monika","family":"J\u00fcrgenson","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, University of Tartu, Tartu, Estonia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4484-2096","authenticated-orcid":false,"given":"Jaanus","family":"Harro","sequence":"additional","affiliation":[{"name":"Department of Psychology, University of Tartu, Tartu, Estonia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anti","family":"Kalda","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, University of Tartu, Tartu, Estonia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2020,4,27]]},"reference":[{"key":"bibr1-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.brainres.2006.10.075"},{"key":"bibr2-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.euroneuro.2009.09.005"},{"key":"bibr3-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1002\/syn.20620"},{"key":"bibr4-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/npp.2010.128"},{"key":"bibr5-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.euroneuro.2013.07.012"},{"key":"bibr6-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuropharm.2018.06.036"},{"key":"bibr7-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1017\/S1461145713000394"},{"key":"bibr8-0269881120916137","doi-asserted-by":"publisher","DOI":"10.3389\/fphar.2017.00985"},{"key":"bibr9-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.nbd.2010.02.014"},{"key":"bibr10-0269881120916137","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.12975"},{"key":"bibr11-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1002\/jnr.20404"},{"key":"bibr12-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nn.3976"},{"key":"bibr13-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.brainres.2006.01.038"},{"key":"bibr14-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.toxlet.2013.01.022"},{"key":"bibr15-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuropharm.2010.06.008"},{"key":"bibr16-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.biochem.74.010904.153721"},{"key":"bibr17-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.pharmthera.2009.11.006"},{"key":"bibr18-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/0924-977X(95)80003-K"},{"key":"bibr19-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/0091-3057(91)90308-O"},{"key":"bibr20-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1126\/science.1210597"},{"key":"bibr21-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.3634-12.2013"},{"key":"bibr22-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1126\/science.1169786"},{"key":"bibr23-0269881120916137","unstructured":"Laerd Statistics (2015) Available at: http:\/\/statistics.laerd.com\/ (accessed 16 February 2018)."},{"key":"bibr24-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nn.2619"},{"key":"bibr25-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1111\/ejn.12480"},{"key":"bibr26-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nrg887"},{"key":"bibr27-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbr.2006.11.022"},{"key":"bibr28-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.brainres.2007.11.041"},{"key":"bibr29-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.3053-14.2015"},{"key":"bibr30-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nature05860"},{"key":"bibr31-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nn.3923"},{"key":"bibr32-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/npp.2012.112"},{"key":"bibr33-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuropharm.2013.04.004"},{"key":"bibr34-0269881120916137","doi-asserted-by":"publisher","DOI":"10.3389\/fpsyt.2012.00060"},{"key":"bibr35-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/S0092-8674(00)81656-6"},{"key":"bibr36-0269881120916137","first-page":"683","volume":"19","author":"Otter M-H","year":"1997","journal-title":"Methods Find Exp Clin Pharmacol"},{"key":"bibr37-0269881120916137","volume-title":"The Rat Brain in Stereotaxic Coordinates","author":"Paxinos G","year":"2007","edition":"6"},{"key":"bibr38-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1126\/science.2781295"},{"key":"bibr39-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/S0165-0173(97)00021-0"},{"key":"bibr40-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuropharm.2013.05.005"},{"key":"bibr41-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.pharep.2015.02.002"},{"key":"bibr42-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/0165-0173(93)90013-P"},{"key":"bibr43-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1007\/s12035-018-1453-6"},{"key":"bibr44-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nprot.2008.73"},{"key":"bibr45-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbr.2016.05.002"},{"key":"bibr46-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1016\/j.cobeha.2018.06.009"},{"key":"bibr47-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkq684"},{"key":"bibr48-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0033435"},{"key":"bibr49-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1111\/adb.12720."},{"key":"bibr50-0269881120916137","doi-asserted-by":"crossref","first-page":"1440","DOI":"10.1176\/ajp.156.9.1440","volume":"156","author":"Volkow ND","year":"1999","journal-title":"Am J Psychiatry"},{"key":"bibr51-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1002\/syn.10137"},{"key":"bibr52-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/mp.2017.208"},{"key":"bibr53-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1111\/j.1360-0443.2010.03321.x"},{"key":"bibr54-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.5227-14.2015"},{"key":"bibr55-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/nn.4008"},{"key":"bibr56-0269881120916137","doi-asserted-by":"publisher","DOI":"10.1038\/npp.2016.286"}],"container-title":["Journal of Psychopharmacology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0269881120916137","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/0269881120916137","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0269881120916137","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T00:10:10Z","timestamp":1777507810000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/0269881120916137"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4,27]]},"references-count":56,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2020,6]]}},"alternative-id":["10.1177\/0269881120916137"],"URL":"https:\/\/doi.org\/10.1177\/0269881120916137","relation":{},"ISSN":["0269-8811","1461-7285"],"issn-type":[{"value":"0269-8811","type":"print"},{"value":"1461-7285","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4,27]]}}}