title: Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease.
abstract: The existence of the nervous form of Chagas disease is a matter of discussion since Carlos Chagas described neurological disorders, learning and behavioural alterations in Trypanosoma cruzi-infected individuals. In most patients, the clinical manifestations of the acute phase, including neurological abnormalities, resolve spontaneously without apparent consequence in the chronic phase of infection. However, chronic Chagas disease patients have behavioural changes such as psychomotor alterations, attention and memory deficits, and depression. In the present study, we tested whether or not behavioural alterations are reproducible in experimental models. We show that C57BL/6 mice chronically infected with the Colombian strain of T. cruzi (150 days post-infection) exhibit behavioural changes as (i) depression in the tail suspension and forced swim tests, (ii) anxiety analysed by elevated plus maze and open field test sand and (iii) motor coordination in the rotarod test. These alterations are neither associated with neuromuscular disorders assessed by the grip strength test nor with sickness behaviour analysed by temperature variation sand weight loss. Therefore, chronically T. cruzi-infected mice replicate behavioural alterations (depression and anxiety) detected in Chagas disease patients opening an opportunity to study the interconnection and the physiopathology of these two biological processes in an infectious scenario.
authors.affiliation: Laboratório de Biologia das Interações, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: Glaucia
authors.initials: G
authors.lastname: Vilar-Pereira
authors.affiliation: Laboratório de Biologia das Interações, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: Leonardo Alexandre de Souza
authors.initials: LA
authors.lastname: Ruivo
authors.affiliation: Laboratório de Biologia das Interações, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: Joseli
authors.initials: J
authors.lastname: Lannes-Vieira
mesh_terms: D000818:Animals; D001007:Anxiety / Q000469:parasitology*; D000067290:Behavior Rating Scale; D002490:Central Nervous System / Q000469:parasitology; D014355:Chagas Disease / Q000150:complications*; D002908:Chronic Disease; D003863:Depression / Q000469:parasitology*; D004195:Disease Models, Animal; D005260:Female; D019417:Hindlimb Suspension; D055809:Illness Behavior; D008810:Mice, Inbred C57BL; D009043:Motor Activity; D053580:Muscle Strength / Q000502:physiology; D018512:Parasitemia / Q000401:mortality; D005082:Physical Exertion; D004856:Postural Balance / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D013550:Swimming; D014349:Trypanosoma cruzi