Conditioned food aversion in Suncus murinus (house musk shrew) - a new model for the study of nausea in a species with an emetic reflex.
The lack of a small animal model with an emetic reflex in which the relationship between conditioned food aversion and emesis could be investigated prompted a study of the insectivore, Suncus murinus (the house musk shrew). A novel food (either tuna or chicken cat food) was paired (C+) with a single exposure to either nicotine (4 mg/kg sc), motion (1 Hz, 4 cm, 10 min) or lithium chloride (100 mg/kg ip) or was paired (C-) with either saline or sham exposure to motion. Nicotine and motion both induced emesis (retching/vomiting) but lithium chloride did not. All three treatments produced a conditioned food aversion after a single pairing with consumption of C+ food. When given a choice between the two foods, S. murinus given lithium chloride, motion exposure and nicotine consumed, respectively, only 25%, 23% and 1% of their total intake from the C+ food. This study shows that a conditioned food aversion can be readily induced in S. murinus and that the induction of emesis can be uncoupled from food aversion. S. murinus provides a promising new model in which the relationship between emesis, nausea and conditioned food aversion can be investigated.
Smith
J E
JE
Department of Physiology, St. George's Hospital Medical School, Cranmer Terrace, SW17 0RE, London, UK.
Friedman
M I
MI
Andrews
P L
PL
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000502:physiology; D008094:Lithium / Q000494:pharmacology; D008297:Male; D009325:Nausea / Q000139:chemically induced*; D012788:Shrews / Q000502:physiology*; D013649:Taste / Q000187:drug effects*; D014839:Vomiting / Q000139:chemically induced*
D008094:Lithium