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Psychiatry"],"abstract":"<jats:p>Rats infected with the protozoan <jats:italic>Toxoplasma gondii<\/jats:italic> exhibit a reduced aversion to cat odor. This behavioral change is thought to increase trophic transmission of the parasite. Infected male rats also show a greater testicular synthesis of testosterone and epigenetic change in arginine vasopressin within the medial amygdala. Here, we show that exogenous supply of testosterone within MeA of uninfected castrates recapitulates reduction in innate fear akin to behavioral change attributed to the parasite. We also show that castration post establishment of chronic infection precludes changes in fear and medial amygdala arginine vasopressin in the infected male rats. These observations support the role of gonadal hormones and pursuant neuroendocrine changes in mediating the loss of fear in the infected rats. This work also demonstrates that testosterone acting specifically within the medial amygdala sufficiently explains reduced defensive behaviors often observed during the appetitive component of reproductive behaviors.<\/jats:p>","DOI":"10.3389\/fpsyt.2020.00630","type":"journal-article","created":{"date-parts":[[2020,7,2]],"date-time":"2020-07-02T04:50:40Z","timestamp":1593665440000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":15,"title":["Testosterone Acts Within the Medial Amygdala of Rats to Reduce Innate Fear to Predator Odor Akin to the Effects of Toxoplasma gondii Infection"],"prefix":"10.3389","volume":"11","author":[{"given":"Dhiraj Kumar","family":"Singh","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shantala Arundathi","family":"Hari Dass","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samira","family":"Abdulai-Saiku","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ajai","family":"Vyas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2020,7,2]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroscience.2007.06.021","article-title":"The effects of toxoplasma infection on rodent behavior are dependent on dose of the stimulus","volume":"148","author":"Vyas","year":"2007","journal-title":"Neuroscience"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2000.1182","article-title":"Fatal attraction in rats infected with Toxoplasma gondii","volume":"267","author":"Berdoy","year":"2000","journal-title":"Proc Biol Sci"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182008004666","article-title":"Specificity of the Toxoplasma gondii-altered behaviour to definitive versus non-definitive host predation risk","volume":"135","author":"Lamberton","year":"2008","journal-title":"Parasitology"},{"key":"B4","doi-asserted-by":"publisher","first-page":"e1004935","DOI":"10.1371\/journal.ppat.1004935","article-title":"Mechanisms of Host Behavioral Change in Toxoplasma gondii Rodent Association","volume":"11","author":"Vyas","year":"2015","journal-title":"PloS Pathog"},{"key":"B5","doi-asserted-by":"publisher","first-page":"95","DOI":"10.14411\/fp.2010.012","article-title":"Toxoplasma gondii-altered host behaviour: clues as to mechanism of action","volume":"57","author":"Webster","year":"2010","journal-title":"Folia Parasitol (Praha)"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1111\/mec.12042","article-title":"Toxoplasma gondii infection enhances testicular steroidogenesis in rats","volume":"22","author":"Lim","year":"2013","journal-title":"Mol Ecol"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1111\/mec.12888","article-title":"Toxoplasma gondii infection reduces predator aversion in rats through epigenetic modulation in the host medial amygdala","volume":"23","author":"Hari Dass","year":"2014","journal-title":"Mol Ecol"},{"key":"B8","doi-asserted-by":"publisher","first-page":"e27229","DOI":"10.1371\/journal.pone.0027229","article-title":"Protozoan parasite Toxoplasma gondii manipulates mate choice in rats by enhancing attractiveness of males","volume":"6","author":"Dass","year":"2011","journal-title":"PloS One"},{"key":"B9","doi-asserted-by":"publisher","first-page":"e992743","DOI":"10.4161\/19420889.2014.992743","article-title":"Extended epigenotype in a Rattus novergicus - 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