Environmental enrichment is the provision of different substrates to mimic an animal’s natural environment and encourage natural, species-specific behavior. However, the use of enrichment to improve breeding efficiency in mouse models for neurologic conditions is not well described. There are reports that diminished environmental stimuli and chronic isolation can result in the early expression of the Parkinson phenotype in mice with a genetic predisposition to the disease. In this study, we compared the provision of crinkle paper, DietGel, and their combination on reproductive parameters in B6.Cg-Tg(THY1-SNCA*A53T)M53Sud mice. We found that enhanced enrichment combined with enhanced nutrition increased dam weight and decreased the interlitter intervals. In addition, enhanced enrichment increased the production index, number of pups born, pups weaned, and the percent survival of pups. This study underscores the importance of incorporating enrichment to enhance the reproductive parameters in mice that are models of Parkinson disease.
Diagram depicting the experimental design. WT: wild-type C57BL/6J male mice; HET: heterozygous A53T female mice.
The average weight of the dams by group presented in ascending mean values. (A) Standard cage setup (standard chow and cotton square). (B) Enhanced enrichment (standard chow, cotton square, and crinkle paper). (C) Enhanced nutrition (standard chow, diet gel, and cotton square). (D) Both enhanced enrichment and nutrition (standard chow, diet gel, cotton square, and crinkle paper). Error bars are ±2 SD. *, Significance.
Average pup weight expressed in grams by genotype. Wild type: n = 91; A53T: n = 55. Error bars are ± 2 SD. This difference in weight was not statistically significant (95% CI [−0.53 to 0.72], t[93] = 0.282, P = 0.779).
Average pup weight expressed in grams by sex. Male: n = 60; female: n = 86. Error bars are ±2 SD. Weight by sex was not statistically significantly different (U = 2112, z = −1.861, P = 0.063).
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