Wheel access duration in rats: II. Day-night and within-session changes.
Time of day and duration of wheel access were manipulated to see how running changed over days. Young male rats were given 2 hr of wheel access, during either the light or dark phase. Over 24 days, running increased 4-fold in the dark group but remained low and stable in the light group. With rats given either 1 or 4 hr of dark phase wheel access, running increased much more in the 4-hr group (even in Hour 1) than in the 1-hr group. The within-session running pattern for high runners changed from a habituation to a sensitization profile. Running and cocaine self-administration (S. H. Ahmed & G. F. Koob, 1998, 1999) are affected similarly by session length, suggesting running as an interesting addiction model.
Eikelboom
Roelof
R
Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada. reikelbo@wlu.ca
Lattanzio
Sara B
SB
D000818:Animals; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D004195:Disease Models, Animal; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D017440:Photoperiod; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013997:Time Factors
D018765:Dopamine Uptake Inhibitors; D003042:Cocaine