Spiny mice (Acomys) regenerate wounded whisker pad skin with whisker follicles, muscles, and targeted innervation.

Varholick, J.A., *Kondapaneni, R., Maden, M. (2025). npj Regenerative Medicine, 10:28

This is the first study to demonstrate that spiny mice can regenerate their whisker follicles and the associated structures after removal. Starting a new model system for studying cutaneous nerve regeneration.

Integrating regenerative biology with developmental psychobiology to understand behavioral recovery.

Varholick, J.A. (2025). Developmental Dynamics Early View

This is a theory paper establishing the intimate connection of behavior and neuroplasticity with tissue regeneration.

Stroke-induced neuroplasticity in the spiny mouse, Acomys cahirinus.

*Kidd, B.M., Varholick, J.A., *Tuyn, D.M., Kamat, P.K., Simon, Z.D., Liu, L., Meckler, M.P., Pompilus, M., Bubenik, J.L., Davenport, M.L., Carter, H.A., Grudny, M.M., Barbazuk, W.B., Doré, S., Febo, M., Candelario-Jalil, E., Maden, M., Swanson, M.S. (2024). npj Regenerative Medicine 9, 41.

After a severe stroke, spiny mice couldn't regenerate their brain, but they fully recovered behaviors within 48 hours. We collaborated on behavioral ethograms and assisted with MRI scans for this project.

A bespoke water T-maze apparatus and protocol: An optimized, reliable, and repeatable method for screening learning, memory, and executive functioning in laboratory mice.

Bailoo, J.D., Bergeson, S.E., Ponomarev, I., Wilms, J.O., Kisby, B.R., Cornwall, G.A., MacDonald, C.C., Lawrence, J.J., Ganapathy, V., Sivaprakasam, S., Panthagani, P., Trasti, S., Varholick, J.A., Findlater, M., Deonarine, A. (2024). Frontiers in Behavioral Neuroscience, Learning and Memory, 18.

This work introduces a novel water T-maze that is less stressful, more efficient, and more reliable compared to the traditional Morris water maze.

A systematic review and meta-analysis of the relationship between social dominance status and common behavioral phenotypes in male laboratory mice.

Varholick, J.A., Bailoo, J.D., *Jenkins, A., Voelkl, B., Würbel, H. (2021). Frontiers in Behavioral Neuroscience, Learning and Memory, 14(624036).

It is well known that lab mice establish dominance structures in their home-cage, this systematic review determined that methods of measuring dominance and stability are too heterogenous to conclude whether dominance is impacting common behavioral measures in neuroscience.

Effects of weaning age and housing conditions on phenotypic differences in mice.

Bailoo, J.D., Voelkl, B., Varholick, J.A., Novak, J., Eimear, M., Russo, M., Palme, R., Würbel, H. (2020). Scientific Reports, 10(11684).

The time of weaning and the type of housing (grouped vs single) varies across experiments. However, in the wild, mice naturally wean themselves. Unexpectedly, altering weaning time and housing type had minimal effects on a broad range of phenotypic measures and likely has little effect on reproducibility in mouse experiments.

Social dominance hierarchy type and rank contribute to phenotypic variation within cages of laboratory mice.

Varholick, J.A., *Pontiggia, A., Murphy, E., *Daniele, V., Palme, R., Voelkl, B., Würbel, H., Bailoo, J.D. (2019). Scientific Reports, 9(13650).

The stability of dominance relationships and the position within, consistently accounts for random variation on a range of phenotypic measures.

Effects of cage enrichment on behavior, welfare and outcome variability in female mice.

Bailoo, J.D., Murphy, E., Boada-Sana, M., Varholick, J.A., Hintze, S., Baussiere, C., Hahn, K.C., Gopfert, C., Palme, R., Voelkl, B., Würbel, H. (2018). Frontiers in Behavioral Neuroscience, 12, p 232.

Environmental enrichment is thought to increase phenotypic variation within studies, here we provide evidence that variability in enriched animals was similar to those housed in barren conditions. Moreover, enriched conditions reduced stereotypic behavior.

Phenotypic variability between social dominance ranks in laboratory mice.

Varholick, J.A., Bailoo, J.D., Palme, R., Würbel, H. (2018). Scientific Reports, 8(6593).

While it is generally thought that mice have stable dominance relationships in their home-cage, we found that dominance was more dynamic and has little effect on a range of phenotypic measures.

Evaluation of space allowance on measures of animal welfare and outcome variation in laboratory mice.

Bailoo, J.D., Murphy, E., Varholick, J.A., Novak, J., Palme, R., Voelkl, B., Würbel, H. (2018). Scientific Reports, 8(713).

Despite discussion of larger cage size and variability in group size affecting results, we found no such effects. Thus, studies should consider group housing mice in larger cages. Albeit large groups can become problematic for fighting in males.

Maternal separation followed by isolation-housing differentially affects prepulse inhibition of the acoustic startle response in C57BL/6 mice.

Bailoo, J. D., Varholick, J. A., Garza, X. J., Jordan, R. L., & Hintze, S. (2016). Developmental Psychobiology, 58(8), 937-944.