title: Characterization of mice lacking the gene for cholecystokinin.
abstract: CCK acts peripherally as a satiating peptide released during meals in response to lipid feeding and centrally functions in the modulation of feeding, exploratory, and memory activities. The present study determined metabolic parameters, food intake, anxiety-like behaviors, and cognitive function in mice lacking the CCK gene. We studied intestinal fat absorption, body composition, and food intake of CCK knockout (CCK-KO) mice by using the noninvasive measurement of intestinal fat absorption along with quantitative magnetic resonance (QMR) imaging and the DietMax system, respectively. Additionally, exploratory and memory capacities were assessed by monitoring running wheel activity and conducting elevated plus-maze and Morris water-maze tests with these mice. Compared with wild-type (WT) littermate controls, CCK-KO mice had normal food intake, fat absorption, body weight, and body mass. CCK-KO mice ate more food than control animals during the light period and less food during the dark period. Energy expenditure was unchanged between the genotypes; however, CCK-KO mice displayed greater fatty acid oxidation. CCK-KO mice were as active as WT animals in the running wheel test. CCK-KO mice spent more time in the closed arms of an elevated plus-maze, indicative of increased anxiety. Additionally, CCK-KO mice exhibited attenuated performance in a passive avoidance task and impaired spatial memory in the Morris water maze test. We conclude that CCK is involved in metabolic rate and is important for memory and exploration. CCK is intimately involved in multiple processes related to cognitive function and food intake regulation.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Cincinnati, Genome Research Institute, 2120 E. Galbraith Rd., Bldg. A, ML 0507, Cincinnati, OH 45237, USA.
authors.forename: Chun-Min
authors.initials: CM
authors.lastname: Lo
authors.forename: Linda C
authors.initials: LC
authors.lastname: Samuelson
authors.forename: James Brad
authors.initials: JB
authors.lastname: Chambers
authors.forename: Alexandra
authors.initials: A
authors.lastname: King
authors.forename: Justin
authors.initials: J
authors.lastname: Heiman
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Jandacek
authors.forename: Randall R
authors.initials: RR
authors.lastname: Sakai
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Benoit
authors.forename: Helen E
authors.initials: HE
authors.lastname: Raybould
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Woods
authors.forename: Patrick
authors.initials: P
authors.lastname: Tso
mesh_terms: D000818:Animals; D001007:Anxiety / Q000235:genetics / Q000523:psychology; D001362:Avoidance Learning / Q000502:physiology; D001823:Body Composition / Q000235:genetics / Q000502:physiology; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D002766:Cholecystokinin / Q000235:genetics* / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D004041:Dietary Fats / Q000378:metabolism; D004435:Eating / Q000235:genetics / Q000502:physiology; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology; D007408:Intestinal Absorption / Q000235:genetics / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology
chemical_list: D004041:Dietary Fats; D002766:Cholecystokinin