Chronic infection with Toxoplasma gondii causes myenteric neuroplasticity of the jejunum in rats

Auton Neurosci. 2010 Oct 5. [Epub ahead of print]

Chronic infection with Toxoplasma gondii causes myenteric neuroplasticity of the jejunum in rats
Hermes-Uliana C, Pereira-Severi LS, Luerdes RB, Franco CL, da Silva AV, Araújo EJ, Sant'ana DD.

Programa de Pós-Graduação em Ciência Animal, Universidade Paranaense, (UNIPAR), Paraná, Brazil.

Abstract
Toxoplasma gondii is an aetiological agent of toxoplasmosis, which commonly causes diarrhoea in a number of species. This observation and the parasite's affinity for the nervous tissue support the theory that T. gondii infection may affect the myenteric neurons. The aim of this study was to evaluate the changes caused by T. gondii (genotype III) in the myenteric neurons of the jejunum in rats. Fifteen rats were distributed into three groups: control (CG), inoculated for 30days (G30) and inoculated for 90days (G90). Rats from the G30 and G90 groups received an oral inoculum with 500 oocysts from a genotype III (M7741) T. gondii strain. At 180days of age, all animals were anaesthetised and euthanised. Whole mounts were stained by using Giemsa (total population) and NADPH-diaphorase (nitrergic subpopulation) histochemistry. Maintenance of the width, length, area and neuronal density was observed; there was neuronal atrophy in the G30 group and a tendency to hypertrophy in the G90 group. Rats inoculated orally with sporulated oocysts did not show clinical illness or macroscopic or microscopic lesions, as do the majority of animal species. Therefore, infection was confirmed by a serum agglutination test; 30days of infection caused increased weight gain and atrophy of myenteric neurons. At 90days post-infection, weight gain became normal, and myenteric neurons hypertrophied.

PMID: 20932812 [PubMed - as supplied by publisher]