The effects of number of trials per day, retention interval, gender and time of day on acquisition of a two-choice, win-stay water-escape working memory task in the rat.
A 2 x 2 x 2 factorial study was conducted to examine the effects of gender, trials/day (TPD), and retention interval (RI) on acquisition of a two-choice win-stay water-escape task in 4-month-old Sprague-Dawley rats. Variations of this task have previously been shown to be sensitive to changes in working memory that occur with age (Means and Kennard, 1991) or to follow treatment with an anxiolytic (Bass et al., 1989) or with cognitive enhancers (Comer and Moore, in press) in males or to estrogen in ovariectomized females (O'Neal et al., 1990). Both training with 1 TPD and with a 5-min RI, time between an information "run" and a test "run", reduced errors during acquisition as compared to giving 3 TPD and a 1-min RI (P less than 0.05 in all cases). Males made fewer errors than did females (P less than 0.05). The three effects were additive: males trained with 1 TPD and a 5-min RI performed best and females trained with 3 TPD and a 1-min RI performed worst. Also, rats given 1 TPD made fewer acquisition errors when trained 2 h before the lights were turned off than when trained during the middle of the light portion of the light/dark cycle (P less than 0.05). Finally, when given 3 TPD, the rats, especially the females, performed significantly worse on their third trial (P less than 0.05). It was concluded that two-choice win-stay water-escape is a very sensitive assay of working memory with much potential for neurobehavioral research.
Means
L W
LW
Department of Psychology, East Carolina University, Greenville, NC 27858.
Dent
M F
MF
D000818:Animals; D003216:Conditioning, Operant / Q000502:physiology*; D005260:Female; D008297:Male; D008568:Memory / Q000502:physiology*; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics; D013997:Time Factors