Lewis rats are more sensitive than Fischer rats to successive negative contrast, but less sensitive to the anxiolytic and appetite-stimulating effects of chlordiazepoxide.

Full Abstract

Lewis rats show greater anticipatory contrast effects than Fischer 344 rats. Specifically, relative to Fischer rats, Lewis rats exhibit greater avoidance of a saccharin cue when it predicts the future availability of a preferred sucrose reward [Grigson, P.S., Freet, C.S. The suppressive effects of sucrose and cocaine, but not lithium chloride, are greater in Lewis than in Fischer rats:
evidence for the reward comparison hypothesis. Behav Neurosci 2000;114:353-363.]. Experiment 1 was designed to determine whether Lewis rats also would demonstrate greater contrast in another paradigm, successive negative contrast (SNC). The results demonstrated a tendency for greater SNC in Lewis rats and then slower recovery from the unexpected loss of reward relative to the Fischer rats. Pretreatment with the anxiolytic agent, chlordiazepoxide (CDP), effectively eliminated contrast in the Fischer rats, but served to prolong recovery from contrast in the Lewis rats. Finally, the results of Experiment 2 demonstrated that Fischer rats, but not Lewis rats, increase consumption of a 0.1 M sucrose solution following pretreatment with CDP. Together, the results show that, while both Lewis and Fischer rats demonstrate SNC, the effect is more sustained in the Lewis rats and these rats are insensitive to both the anxiolytic and the appetite-stimulating effects of CDP.

Learn Faster Today Improve your study skills

Author information

Author/s: Freet, Christopher S (CS); Tesche, Jason D (JD); Tompers, Dennie M (DM); Riegel, Katherine E (KE); Grigson, Patricia S (PS);

Affiliation: The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA. csf5(-atsign-)psu.edu

Grants: DA09815 (Agency:NIDA NIH HHS) ; DA12473 (Agency:NIDA NIH HHS) ; R01 DA009815-09A2 (Agency:NIDA NIH HHS) ; R01 DA012473-05 (Agency:NIDA NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, N.I.H., Extramural

Journal: Pharmacology, biochemistry, and behavior (Pharmacol Biochem Behav), published in United States. (Language: eng)

Reference: 2006-Oct; vol 85 (issue 2) : pp 378-84

Dates: Created 2006/12/18; Completed 2007/02/20; Revised 2008/11/20;

PMID: 17049372, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Animals
Anti-Anxiety Agents - pharmacology
Appetite Stimulants - pharmacology
Chlordiazepoxide - pharmacology
Male

Associated Chemicals: Anti-Anxiety Agents (0) ; Appetite Stimulants (0) ; Chlordiazepoxide (58-25-3)

These are the highest related articles currently in the database:

See 100+ related articles.