Behavioral and hormonal changes associated with the infective dose in experimental taeniasis in golden hamsters (Mesocricetus auratus).
BACKGROUND
It has been reported that behavioral changes relate to infection in different parasitoses. However, the relation between the extent of the behavioral changes and the magnitude of the infection has been scarcely studied. The aim of this study was to evaluate the relationship between different doses of infection and the behavioral changes induced in the experimental Taenia pisiformis taeniasis in golden hamsters.


METHODS
Groups of nine hamsters were infected with three or six T. pisiformis metacestodes. The locomotor activity was quantified daily in an open field test during the 21 days after infection; anxiety test was performed in an elevated plus-maze with a dark/light area at 7, 14 and 21 days post-infection, and serum cortisol levels were determined by radioimmunoassay before infection and at day 22 after infection.


RESULTS
The challenge itself induced modifications on behavior and cortisol levels in hamsters, with or without successful infection (taenia development). Animals challenged with three metacestodes induced a decrease in locomotor activity and an increase in anxiety in infected animals. A higher and earlier decrease in locomotor activity and increased anxiety levels were observed in hamsters challenged with six cysticerci, which were accompanied by higher levels of sera cortisol at the end of the experiment. At necropsy, 44-55% of hamster became infected with an efficiency of implantation of 22-26%, challenged with three or six cysticerci respectively.


CONCLUSIONS
The challenge of hamsters with metacestodes, promote behavioral changes in an extent dependent on the magnitude of the challenge, disregarding the effectiveness of the infection.
Facultad de Ciencias Agropecuarias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209, Cuernavaca, Morelos, Mexico. Electronic address: rosa.dguez88@gmail.com.
Rosa
R
Domínguez-Roldan
Facultad de Ciencias Agropecuarias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209, Cuernavaca, Morelos, Mexico. Electronic address: challalc@gmail.com.
Claudia
C
Hallal-Calleros
Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, AP 70228, México DF, 04510, Mexico. Electronic address: edda@unam.mx.
Edda
E
Sciutto
Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, AP 70228, México DF, 04510, Mexico. Electronic address: marysel_01@yahoo.com.mx.
Marisela
M
Hernández
Facultad de Ciencias Agropecuarias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209, Cuernavaca, Morelos, Mexico. Electronic address: avirginio@uaem.mx.
Virginio
V
Aguirre-Flores
Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209, Cuernavaca, Morelos, Mexico. Electronic address: saragarcia@uaem.mx.
Sara
S
García-Jiménez
Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, AP 70228, México DF, 04510, Mexico. Electronic address: armida@biomedicas.unam.mx.
Armida
A
Báez-Saldaña
Facultad de Ciencias Agropecuarias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209, Cuernavaca, Morelos, Mexico. Electronic address: ivan.flores@uaem.mx.
Fernando Iván
FI
Flores-Pérez
D000818:Animals; D001007:Anxiety; D001522:Behavior, Animal; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D006790:Host-Parasite Interactions; D006854:Hydrocortisone / Q000097:blood*; D016867:Immunocompromised Host; D008124:Locomotion; D008647:Mesocricetus; D010529:Peritoneal Cavity / Q000469:parasitology; D011817:Rabbits; D011897:Random Allocation; D013621:Taenia / Q000502:physiology; D013622:Taeniasis / Q000276:immunology / Q000378:metabolism* / Q000523:psychology*
D006854:Hydrocortisone
Behavior; Experimental taeniasis; Hamster; Hormonal changes; Host-parasite relationship; Taenia pisiformis