{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T09:48:43Z","timestamp":1770716923263,"version":"3.49.0"},"reference-count":31,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2017,10,23]],"date-time":"2017-10-23T00:00:00Z","timestamp":1508716800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2017,10,23]],"date-time":"2017-10-23T00:00:00Z","timestamp":1508716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title><jats:p><jats:italic>Toxoplasma gondii<\/jats:italic> infects a broad range of hosts and can establish chronic infections with the formation of brain cysts. Infected animals show altered risk behaviour which has been suggested to increase capture probability of hosts, and thus enhance parasite transmission. It has been proposed that the ability of <jats:italic>Toxoplasma<\/jats:italic> cysts to secrete tyrosine hydroxylase could mediate these behavioural alterations. We tested the involvement of secreted tyrosine hydroxylase, coded by the parasite <jats:italic>AaaH2<\/jats:italic> gene, in the development of alterations in mouse behaviour, by generating an <jats:italic>AaaH2<\/jats:italic> deletion mutant parasite strain and testing its influence on behaviour. We found that both mice infected with wild type or <jats:italic>AaaH2<\/jats:italic> mutant strains showed changes in risk behaviour. We confirmed these findings using factor analysis of the behaviour, which revealed that behavioural changes happened along a single dimension, and were observed in both infected groups. Furthermore, we developed a new behavioural paradigm in which animals are unpredictably trapped, and observed that both groups of infected animals perceive trapping but fail to adjust their behaviour to avoid further trapping. These results demonstrate that parasite-secreted AaaH2 TH is neither necessary for the generation of risky behaviour nor for the increased trappability observed during chronic <jats:italic>Toxoplasma<\/jats:italic> infection.<\/jats:p>","DOI":"10.1038\/s41598-017-13229-y","type":"journal-article","created":{"date-parts":[[2017,10,17]],"date-time":"2017-10-17T14:29:47Z","timestamp":1508250587000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Toxoplasma-induced changes in host risk behaviour are independent of parasite-derived AaaH2 tyrosine hydroxylase"],"prefix":"10.1038","volume":"7","author":[{"given":"Cristina","family":"Afonso","sequence":"first","affiliation":[]},{"given":"Vitor B.","family":"Paix\u00e3o","sequence":"additional","affiliation":[]},{"given":"Andreas","family":"Klaus","sequence":"additional","affiliation":[]},{"given":"Matteo","family":"Lunghi","sequence":"additional","affiliation":[]},{"given":"Federica","family":"Piro","sequence":"additional","affiliation":[]},{"given":"Carla","family":"Emiliani","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4154-5210","authenticated-orcid":false,"given":"Manlio","family":"Di Cristina","sequence":"additional","affiliation":[]},{"given":"Rui M.","family":"Costa","sequence":"additional","affiliation":[]}],"member":"297","published-online":{"date-parts":[[2017,10,23]]},"reference":[{"key":"13229_CR1","doi-asserted-by":"publisher","first-page":"1217","DOI":"10.1016\/S0020-7519(00)00124-7","volume":"30","author":"AM Tenter","year":"2000","unstructured":"Tenter, A. 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