In mice the ability to run normally is a dominant trait VideoHow to trap mice with balloons 2020 in mice the ability to run normally is a dominant trait
UBC Theses and Dissertations
This greater encephalization has come with increased behavioral complexity and, more info, it has http://rectoria.unal.edu.co/uploads/tx_felogin/why-do-cosmetic-for-our-business-which/what-is-the-difference-between-aerobic-and-anaerobic-respiration.php suggested that selection on behavioral traits has been a significant factor leading to the evolution of larger whole-brain mass.
In addition, brains may evolve in a mosaic fashion, with functional components having some freedom to evolve independently from other components, irrespective of, or in addition to, changes in size of the whole brain. We tested whether long-term selective breeding for high voluntary wheel running in laboratory house mice results in changes in brain size, and whether those norjally have occurred in a concerted or mosaic fashion. We measured wet and dry brain mass via dissections and brain volume with ex vivo magnetic resonance imaging of brains that distinguished the caudate-putamen, hippocampus, midbrain, cerebellum and forebrain.
Adjusting for body mass as a covariate, mice from the four replicate high-runner HR lines had statistically larger non-cerebellar wet and dry brain masses than those from four non-selected control lines, with no jn in cerebellum wet or dry mass or volume.
We hypothesize that the enlarged midbrain of HR mice is related to altered neurophysiological function in their dopaminergic system. To our knowledge, this is the first example in which selection for a particular mammalian behavior has been shown to result in a change in size of a specific brain region. This observation was applied primarily to sensory processing areas of the brain e.
However, there is a general trend in mammals for increased behavioral complexity with increased brain size i. Differences in behavioral complexity are difficult to quantify and are subject tralt variable interpretation Changizi, ; Chittka and Niven, Both increased sensitivity to sensory stimuli Land and Nilsson, and increased precision in motor ability Sparks, are directly related to increases in neuron number, which, in turn, are directly related to brain size Herculano-Houzel et al.
Likewise, species of mammals Sol et al. Of course, changes in brain size alone obviously do not account http://rectoria.unal.edu.co/uploads/tx_felogin/benjamin-franklin-s-theory-of-life-and/types-of-political-systems.php all behavioral evolution e. It is unclear whether selection on a behavioral trait would result in a coordinated enlargement of the entire brain Finlay and Darlington, ; Clancy et al.
This latter theory, called mosaic evolution of the brain, suggests that brain systems mediating specific behavioral capacities are able to change size in response to selection Barton and Harvey, ; de Winter and Oxnard, ]