Murray State University
Experimental Analysis of the Relationship Between Parasite Burden and Cognitive Abilities in House Mice (Mus musculus)
Institution
Murray State University
Faculty Advisor/ Mentor
Terry Derting
Abstract
During early mammalian development, the energetic cost of mounting an immune response may deplete available energy allotments from other biological processes such as brain development. Eppig et al. reported that parasitic infections may affect development of an organism’s nervous system, resulting in reduced cognitive ability. Our goal was to determine whether parasitic burden is related with cognitive ability. We tested the null hypothesis that parasitism does not affect the cognitive ability of lab mice. Using Mus musculus, adults were bred and neonates from 10 litters were infected with the gastrointestinal nematode Heligmosomoides polygyrus. Control neonates from those same 10 litters were not infected for comparison. At 21 days of age, both groups were subjected to parasite load enumeration through fecal egg counts. At 35 days of age, both groups were subjected to a spatial memory test using a T-maze. After T-maze completion, each mouse was euthanized and the brain removed and mass recorded after drying. There was no significant difference in the dry brain mass of the parasitized and non-parasitized mice. We also failed to see any significant difference between the percent of successful T-maze trials for the parasitized compared with the non-parasitized group. Likewise, within the parasitized mice, parasite egg count and percent success on the T-maze was not correlated significantly. Our work showed that parasitic infection prior to sexual maturation had no effect on the cognitive ability of Mus musculus. These results did not support a relationship between parasitic burden during postnatal development and cognitive ability.
Experimental Analysis of the Relationship Between Parasite Burden and Cognitive Abilities in House Mice (Mus musculus)
During early mammalian development, the energetic cost of mounting an immune response may deplete available energy allotments from other biological processes such as brain development. Eppig et al. reported that parasitic infections may affect development of an organism’s nervous system, resulting in reduced cognitive ability. Our goal was to determine whether parasitic burden is related with cognitive ability. We tested the null hypothesis that parasitism does not affect the cognitive ability of lab mice. Using Mus musculus, adults were bred and neonates from 10 litters were infected with the gastrointestinal nematode Heligmosomoides polygyrus. Control neonates from those same 10 litters were not infected for comparison. At 21 days of age, both groups were subjected to parasite load enumeration through fecal egg counts. At 35 days of age, both groups were subjected to a spatial memory test using a T-maze. After T-maze completion, each mouse was euthanized and the brain removed and mass recorded after drying. There was no significant difference in the dry brain mass of the parasitized and non-parasitized mice. We also failed to see any significant difference between the percent of successful T-maze trials for the parasitized compared with the non-parasitized group. Likewise, within the parasitized mice, parasite egg count and percent success on the T-maze was not correlated significantly. Our work showed that parasitic infection prior to sexual maturation had no effect on the cognitive ability of Mus musculus. These results did not support a relationship between parasitic burden during postnatal development and cognitive ability.