title: Artificial rearing alters the response of rats to natural and drug-mediated rewards.
abstract: Artificial rearing (AR) of infant rats permits precise control over key features of the early environment without maternal influence. The present study examined the behavioral response of AR rats towards natural and drug-mediated rewards, as well as their exploratory and affective behaviors. Adolescent AR rats showed increased preference for sucrose consumption relative to chow and demonstrated greater activity in the open field and in the elevated plus-maze compared to maternally reared (MR) rats. With respect to measures of emotionality, AR rats showed enhanced avoidance of the open arms of the plus-maze, indicating increased anxiety, but they did not differ from MR rats in exploring the center of the open field. Adult AR rats displayed a stronger conditioned response to morphine in a place preference test. These findings support the potential of the AR model to contribute to understanding the role of early experience in the development of behavioral motivation.
authors.affiliation: Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ont. N2L 3G1, Canada.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Lomanowska
authors.forename: Shadna A
authors.initials: SA
authors.lastname: Rana
authors.forename: Dawn
authors.initials: D
authors.lastname: McCutcheon
authors.forename: Linda A
authors.initials: LA
authors.lastname: Parker
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Wainwright
mesh_terms: D000339:Affect / Q000187:drug effects*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000254:growth & development; D003213:Conditioning, Psychological; D005260:Female; D005518:Food Preferences; D005774:Gastrostomy; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012931:Social Environment; D013395:Sucrose
chemical_list: D009294:Narcotics; D013395:Sucrose; D009020:Morphine