title: Effects of treadmill exercise on the LiCl-induced conditioned taste aversion in rats.
abstract: Studies have shown that exercise can enhance learning and memory. Conditioned taste aversion (CTA) is an avoidance behavior induced by associative memory of the taste sensation for something pleasant or neutral with a negative visceral reaction caused by the coincident action of a toxic substance that is tasteless or administered systemically. We sought to measure the effects of treadmill exercise on CTA in rats by investigating the effects of exercise on acquisition, extinction and spontaneous recovery of CTA. We made two groups of rats: an exercise group that ran on a treadmill, and a control group that did not have structured exercise periods. To condition rats to disfavor a sweet taste, consumption of a 0.1% saccharin solution in place of drinking water was paired with 0.15M LiCl (2% body weight, i.p.) to induce visceral discomfort. We measured changes of saccharin consumption during acquisition and extinction of CTA. The exercise and no-exercise groups both acquired CTA to similar levels and showed maximum extinction of CTA around 6 days after acquisition. This result indicates that exercise affects neither acquisition nor extinction of CTA. However, in testing for preservation of CTA after much longer extinction periods that included exercise or not during the intervening period, exercising animals showed a significantly lower saccharin intake, irrespective of having exercised or not during the conditioning phase of the trial. This result suggests that exercise may help to preserve aversive memory (taste aversion in this example) as evidence by the significant spontaneous recovery of aversion in exercising animals.
authors.affiliation: Department of Gerodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan; Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: tsubodon@den.hokudai.ac.jp.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Tsuboi
authors.affiliation: Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: hirai@den.hokudai.ac.jp.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hirai
authors.affiliation: Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: maezawa@den.hokudai.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maezawa
authors.affiliation: Department of Gerodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: kjnotani@den.hokudai.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Notani
authors.affiliation: Department of Gerodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: nobu@den.hokudai.ac.jp.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Electronic address: mfuna@den.hokudai.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Funahashi
mesh_terms: D000818:Animals; D001245:Association Learning; D001362:Avoidance Learning; D003214:Conditioning, Classical; D004327:Drinking Behavior; D060766:Drinking Water; D005108:Extinction, Psychological; D018021:Lithium Chloride / Q000008:administration & dosage; D008297:Male; D009043:Motor Activity; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000008:administration & dosage; D055697:Taste Perception; D013997:Time Factors
chemical_list: D060766:Drinking Water; D012439:Saccharin; D018021:Lithium Chloride
keywords: Conditioned taste aversion; Forced exercise; Memory