Effects of bright light on responsiveness to a muscarinic agonist in rats selectively bred for endogenously increased cholinergic function.

Journal Article (Journal Article)

The Flinders Sensitive Line (FSL) was derived from the Sprague-Dawley rat by selectively breeding those animals exhibiting a high level of sensitivity to an anticholinesterase. The Flinders Resistant Line (FRL) was simultaneously developed as a control line. These lines exhibit nonoverlapping distributions of their thermic responsiveness to oxotremorine. Bright light prevents the development of supersensitivity to oxotremorine occurring as a result of forced stress or treatment with a muscarinic receptor antagonist in the rat. The authors now report that treatment with bright light during the regular photoperiod (i.e., a time that does not produce a phase-shift or free-running) differentially affects the hypothermic response and activity-suppressing effect of oxotremorine in both the FSL and FRL. Both lines exhibit decreased hypothermia without reduction in motor activity in response to oxotremorine following 6 days of treatment with bright light. The magnitude of blunting of the hypothermic response was greater in the FSL than the FRL. These findings suggest that (1) studies of the effects of bright light are contingent on the end point one measures and (2) the capacity of this treatment to blunt the hypothermic response to a muscarinic agonist is greater in an animal model with endogenously hyperactive muscarinic cholinergic systems.

Full Text

Duke Authors

Cited Authors

  • Overstreet, DH; Dilsaver, SC; Janowsky, DS; Rezvani, AH

Published Date

  • August 1990

Published In

Volume / Issue

  • 33 / 2

Start / End Page

  • 139 - 150

PubMed ID

  • 2243891

International Standard Serial Number (ISSN)

  • 0165-1781

Digital Object Identifier (DOI)

  • 10.1016/0165-1781(90)90068-g


  • eng

Conference Location

  • Ireland