title: Little and often? Maintaining continued performance in an automated T-maze for mice.
abstract: Operant and maze tasks in mice are limited by the small number of trials possible in a session before mice lose motivation. We hypothesized that by manipulating reward size and session length, motivation, and hence performance, would be maintained in an automated T-maze. We predicted that larger rewards and shorter sessions would improve acquisition; and smaller rewards and shorter sessions would maintain higher and less variable performance. Eighteen C57BL/6J mice (9 per sex) acquired (criterion 8/10 correct) and performed a spatial discrimination, with one of 3 reward sizes (.02, .04, or .08 g) and one of 3 session schedules (15, 30, or 45 min sessions). Each mouse had a total of 360 min of access to the maze per night, for two nights, and averaged 190 trials. Analysis used split-plot GLM with contrasts testing for linear effects. Acquisition of the discrimination was unaffected by reward size or session length/interval. After-criterion average performance improved as reward size decreased. After-criterion variability in performance was also affected. Variability increased as reward size increased. Session length/interval did not affect any outcome. We conclude that an automated maze, with suitable reward sizes, can sustain performance with low variability, at 5-10 times faster than traditional methods.
authors.affiliation: Animal Behavior and Well-Being Group, Department of Animal Science, Purdue University, 915 West State Street, West Lafayette, IN 47907, USA. bgaskill@purdue.edu
authors.forename: Brianna N
authors.initials: BN
authors.lastname: Gaskill
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Lucas
authors.forename: Edmond A
authors.initials: EA
authors.lastname: Pajor
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Garner
mesh_terms: D000818:Animals; D001331:Automation; D003216:Conditioning, Operant / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D005502:Food; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009042:Motivation; D011589:Psychology, Experimental / Q000295:instrumentation* / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology; D012055:Reinforcement Schedule; D012201:Reward; D012527:Satiation / Q000502:physiology