No effect of running and laboratory housing on adult hippocampal neurogenesis in wild caught long-tailed wood mouse

Abstract

Background: Studies of adult hippocampal neurogenesis (AHN) in laboratory rodents have raised hopes for therapeutic interventions in neurodegenerative diseases and mood disorders, as AHN can be modulated by physical exercise, stress and environmental changes in these animals. Since it is not known whether cell proliferation and neurogenesis in wild living mice can be experimentally changed, this study investigates the responsiveness of AHN to voluntary running and to environmental change in wild caught long-tailed wood mice (Apodemus sylvaticus).

Adult Hippocampal Neurogenesis in Natural Populations of Mammals

“…As a consequence, we and others have argued that AHN might contribute to behavioral flexibility (Amrein et al 2007;Amrein and Lipp 2009;Garthe et al 2009). A comparison of 11 rodent species originating from different habitats supports this hypothesis.…”

“…Baseline: wild mice investigated right after trapping. (Data from Hauser et al 2009 and wild house mice, bred in captivity, small interindividual AHN variation can be observed as well. How can the context sensitivity of AHN in laboratory rodents be explained?…”

“…A decrease in AHN would be expected, but was not observed. After 2 wk of laboratory housing, running and sedentary wild wood mice show exactly the same extent of AHN as wood mice analyzed immediately after trapping, suggesting that a constant pool of functionally distinct young neurons is maintained in these small rodents, despite environmental changes and experimental challenges (Hauser et al 2009). Also, the basal AHN in wild house mice is surprisingly low.…”

“…To investigate whether physical exercise can modulate AHN in free-living rodents, wild long-tailed wood mice (Apodemus sylvaticus) and wild house mice with low basal neurogenesis were tested along with laboratory mice under the same exercise conditions. Voluntary running increases proliferation and neuronal differentiation in laboratory mice, but not in wild wood mice (Hauser et al 2009) or wild house mice (see Fig. 5) ).…”

“…1B), a microtubulin-associated protein found in migrating and maturating young neurons (Matsuo et al 1998;Nacher et al 2001). Using the same markers, quantitative data have been presented for wild longtailed wood mice (Apodemus sylvaticus [Hauser et al 2009]) and F1 of wild trapped house mice (Mus musculus domesticus ). Using BrdU, cell proliferation was observed in the latter species also by Schaefers (2013).…”