Volumes of brain structures in captive wild-type and laboratory rats: 7T magnetic resonance in vivo automatic atlas-based study

PLoS One. 2019 Apr 11;14(4):e0215348. doi: 10.1371/journal.pone.0215348. eCollection 2019.

Abstract

Selective breeding of laboratory rats resulted in changes of their behavior. Concomitantly, the albino strains developed vision related pathologies. These alterations certainly occurred on the background of modifications in brain morphology. The aim of the study was to assess and compare volumes of major structures in brains of wild-captive, laboratory albino and laboratory pigmented rats. High resolution T2-weighted images of brains of adult male Warsaw Wild Captive Pisula-Stryjek rats (WWCPS, a model of wild type), laboratory pigmented (Brown Norway strain, BN) and albino rats (Wistar strain, WI) were obtained with a 7T small animal-dedicated magnetic resonance tomograph. Volume quantification of whole brains and 50 brain structures within each brain were performed with the digital Schwarz rat brain atlas and a custom-made MATLAB/SPM8 scripts. Brain volumes were scaled to body mass, whereas volumes of brain structures were normalized to individual brain volumes. Normalized brain volume was similar in WWCPS and BN, but lower in WI. Normalized neocortex volume was smaller in both laboratory strains than in WWCPS and the visual cortex was smaller in albino WI rats than in WWCPS and BN. Relative volumes of phylogenetically older structures, such as hippocampus, amygdala, nucleus accumbens and olfactory nuclei, also displayed certain strain-related differences. The present data shows that selective breeding of laboratory rats markedly affected brain morphology, the neocortex being most significantly altered. In particular, albino rats display reduced volume of the visual cortex, possibly related to retinal degeneration and the development of blindness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Wild
  • Atlases as Topic
  • Brain / anatomy & histology*
  • Brain / diagnostic imaging*
  • Brain / physiology
  • Domestication
  • Magnetic Resonance Imaging
  • Male
  • Neocortex / anatomy & histology
  • Organ Size
  • Rats
  • Rats, Inbred BN
  • Rats, Wistar
  • Selective Breeding
  • Species Specificity
  • Visual Cortex / anatomy & histology

Grants and funding

This study was supported in part by Polish National Science Centre (http://www.ncn.gov.pl)grant No. DEC-2012/07/D/NZ4/04199) to MF. Project carried out with the use of CePT infrastructure financed by the European Union – the European Regional Development Found in the Operational Programme „Innovative Economy” for 2007-2013. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.