Related Experiment Videos
Decreased predator avoidance in parasitized mice: neuromodulatory correlates
1Division of Oral Biology, Faculty of Dentistry, University of Western Ontario, London, Canada.
Parasitology
|September 1, 1995
Summary
Parasite infection with Eimeria vermiformis reduces mouse avoidance of cat odor, indicating altered predator fear responses. This effect involves gamma-aminobutyric acid A (GABAA) receptor mechanisms, not opioid pathways.
Area of Science:
- Neuroparasitology
- Behavioral Neuroscience
- Immunology
Background:
- Parasites can modify host behavior, but neurochemical underpinnings are poorly understood.
- Eimeria vermiformis is a common enteric protozoan parasite affecting laboratory mice.
Purpose of the Study:
- To investigate the neurochemical mechanisms by which Eimeria vermiformis infection alters host responses to predator cues.
- To determine if parasite infection reduces predator-induced anxiety and fear in mice.
Main Methods:
- An odour preference test was used to assess responses of infected and uninfected male mice to cat odour.
- Pharmacological manipulations included opioid agonists/antagonists, GABAA antagonists, benzodiazepine antagonists, and NMDA antagonists.
Main Results:
- Infected mice showed significantly reduced avoidance of cat odour compared to uninfected controls.
- This behavioral change was not linked to opioid system alterations.
- GABAA antagonists bicuculline and picrotoxin, but not other tested antagonists, reversed the reduced avoidance in infected mice.
Conclusions:
- Eimeria vermiformis infection alters host anxiety systems, reducing predator avoidance.
- Gamma-aminobutyric acid A (GABAA) receptor mechanisms play a significant role in this parasite-induced behavioral modification.