Toxoplasma gondii-Induced Behavioral Alterations in Domestic Cats (Felis catus)
Advisor Information
Bruce Chase
Location
MBSC 201
Presentation Type
Poster
Start Date
6-3-2020 2:00 PM
End Date
6-3-2020 3:15 PM
Abstract
Domestic cats play pivotal roles in transmitting Toxoplasma gondii: This parasite reproduces sexually only in felid intestines, after which its oocysts are shed in feces for several weeks. Though acute infection in fetal or immunocompromised cats can be lethal, from 18-80% of domestic cats are T. gondii-seropositive and have a chronic, naturally occurring, asymptomatic infection. Though chronic infection affects risk-averse and locomotory behavior in many infected animals, its effect on cat behavior is unknown. We propose that chronic T. gondii infection in domestic cats similarly alters their behavior, specifically to increase its own spread. This idea is based on models of fecally-transmitted disease in areas where resources are shared: if T. gondii mediates the size and characteristics of a cat’s home range, then it will direct where soil is contaminated with fecally-shed T. gondii, which will in turn influence parasite exposure for intermediate hosts as well in cats with overlapping home ranges. We hypothesize that chronic T. gondii infection in domestic cats decreases their risk-averse behavior and leads to increased locomotor activity and exploration. To pilot-test this, we have developed a non-invasive paradigm to evaluate behavioral changes caused by latent T. gondii infection. We used a controlled environment to test whether T. gondii-infected cats exhibit altered risk-aversion behavior. Because natural ecosystems include a suite of species that vary in their roles as hosts for T. gondii, this study provides a foundational understanding of whether the nature of the host (obligate versus intermediate) affects how T. gondii manipulates host behavior. We recruited owners of pet cats, then cross-sectionally evaluated whether risk-aversion and locomotory activity in their cats differ by seropositive status. In one behavioral paradigm, cat behavior is recorded over a series of episodes with and without the owner. When the owner is present, s/he sits and interacts with their cat. After an initial set of familiarization episodes, a balanced scent-based paradigm is used to evaluate a risk-averse response. We demonstrate that this least-invasive paradigm is useful to infer behavioral changes that may result from alteration of dopamine tone via T. gondii infection. This work contribute to a theoretical framework to understand how the risk of infection by fecal-transmitted parasites is influenced by patterns of cat behavior and inform guidelines for controlling this parasite’s spread.
Toxoplasma gondii-Induced Behavioral Alterations in Domestic Cats (Felis catus)
MBSC 201
Domestic cats play pivotal roles in transmitting Toxoplasma gondii: This parasite reproduces sexually only in felid intestines, after which its oocysts are shed in feces for several weeks. Though acute infection in fetal or immunocompromised cats can be lethal, from 18-80% of domestic cats are T. gondii-seropositive and have a chronic, naturally occurring, asymptomatic infection. Though chronic infection affects risk-averse and locomotory behavior in many infected animals, its effect on cat behavior is unknown. We propose that chronic T. gondii infection in domestic cats similarly alters their behavior, specifically to increase its own spread. This idea is based on models of fecally-transmitted disease in areas where resources are shared: if T. gondii mediates the size and characteristics of a cat’s home range, then it will direct where soil is contaminated with fecally-shed T. gondii, which will in turn influence parasite exposure for intermediate hosts as well in cats with overlapping home ranges. We hypothesize that chronic T. gondii infection in domestic cats decreases their risk-averse behavior and leads to increased locomotor activity and exploration. To pilot-test this, we have developed a non-invasive paradigm to evaluate behavioral changes caused by latent T. gondii infection. We used a controlled environment to test whether T. gondii-infected cats exhibit altered risk-aversion behavior. Because natural ecosystems include a suite of species that vary in their roles as hosts for T. gondii, this study provides a foundational understanding of whether the nature of the host (obligate versus intermediate) affects how T. gondii manipulates host behavior. We recruited owners of pet cats, then cross-sectionally evaluated whether risk-aversion and locomotory activity in their cats differ by seropositive status. In one behavioral paradigm, cat behavior is recorded over a series of episodes with and without the owner. When the owner is present, s/he sits and interacts with their cat. After an initial set of familiarization episodes, a balanced scent-based paradigm is used to evaluate a risk-averse response. We demonstrate that this least-invasive paradigm is useful to infer behavioral changes that may result from alteration of dopamine tone via T. gondii infection. This work contribute to a theoretical framework to understand how the risk of infection by fecal-transmitted parasites is influenced by patterns of cat behavior and inform guidelines for controlling this parasite’s spread.