title: Circannual changes in the duration of the immobility response of rats in the forced swim test.
abstract: Separate groups of male rats were tested in the forced swim test on the third Tuesday of each mo for 14 mo. A distinct pattern was observable in their immobility response such that animals were most immobile during the winter months (Dec-Mar) and least immobile during the summer months (June-Sept). Bicarbonate-carbon dioxide levels were significantly correlated with immobility times (r = 0.48), as were glucose (r = 0.34) and phosphorus (r = -0.33) levels, whereas corticosterone and testosterone levels were not significantly correlated with immobility. These results indicate that there is a circannual rhythm in the floating behavior of rats in the forced swim test.
authors.affiliation: Department of Obstetrics and Gynecology, C.S. Mott Center for Human Growth and Development, Wayne State University, Detroit, MI, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Abel
mesh_terms: D000818:Animals; D001143:Arousal / Q000502:physiology*; D001639:Bicarbonates / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood; D003345:Corticosterone / Q000097:blood; D008297:Male; D009042:Motivation; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012621:Seasons; D013550:Swimming; D013739:Testosterone / Q000097:blood
chemical_list: D001639:Bicarbonates; D001786:Blood Glucose; D002245:Carbon Dioxide; D013739:Testosterone; D003345:Corticosterone