Skip to main content

Open Access Effects of Colored Enrichment Devices on Circadian Metabolism and Physiology in Male Sprague–Dawley Rats

Download Article:
 Download
(PDF 268.3 kb)
 
Environmental enrichment (EE) gives laboratory animals opportunities to engage in species-specific behaviors. However, the effects of EE devices on normal physiology and scientific outcomes must be evaluated. We hypothesized that the spectral transmittance (color) of light to which rats are exposed when inside colored enrichment devices (CED) affects the circadian rhythms of various plasma markers. Pair-housed male Crl:SD rats were maintained in ventilated racks under a 12:12-h light:dark environment (265.0 lx; lights on, 0600); room lighting intensity and schedule remained constant throughout the study. Treatment groups of 6 subjects were exposed for 25 d to a colored enrichment tunnel: amber, red, clear, or opaque. We measured the proportion of time rats spent inside their CED. Blood was collected at 0400, 0800, 1200, 1600, 2000, and 2400 and analyzed for plasma melatonin, total fatty acids, and corticosterone. Rats spent more time in amber, red, and opaque CED than in clear tunnels. All tubes were used significantly less after blood draws had started, except for the clear tunnel, which showed no change in use from before blood sampling began. Normal peak nighttime melatonin concentrations showed significant disruption in the opaque CED group. Food and water intakes and body weight change in rats with red-tinted CED and total fatty acid concentrations in the opaque CED group differed from those in other groups. These results demonstrate that the color of CED altered normal circadian rhythms of plasma measures of metabolism and physiology in rats and therefore might influence the outcomes of scientific investigations.

38 References.

No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Affiliations: 1: Departments of Comparative Medicine and Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA. [email protected] 2: Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA 3: Section of Laboratory Animal Medicine, IIT Research Institute, Chicago, Illinois, USA 4: Division of Veterinary Medicine, Tulane National Primate Research Center, Covington, Louisiana, USA 5: Departments of Comparative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA

Publication date: 01 October 2016

More about this publication?
  • Comparative Medicine (CM), an international journal of comparative and experimental medicine, is the leading English-language publication in the field and is ranked by the Science Citation Index in the upper third of all scientific journals. The mission of CM is to disseminate high-quality, peer-reviewed information that expands biomedical knowledge and promotes human and animal health through the study of laboratory animal disease, animal models of disease, and basic biologic mechanisms related to disease in people and animals.

    Attention Members: To access the full text of the articles, be sure you are logged in to the AALAS website.

    Attention: please note, due to a temporary technical problem, reference linking within the content is not available at this time

  • Editorial Board
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Membership Information
  • Information for Advertisers
  • For issues prior to 1998
  • Institutional Subscription Activation
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more