One-capillary lane-maze test in flies: exploratory studies
Fabiola Boz Eckert, Dhiozer de Brittos Valdati, José Marino Neto, Daniela Cristina de Toni, Cilene Lino de Oliveira
Abstract
Drosophila melanogaster is a candidate species to replace rodents in some neurobiological studies, encouraging attempts to develop behavioural tests for these flies. This study aimed to develop a sucrose preference test in flies that simultaneously assesses the ethological aspects of motor and fluid intake activities in several experimental units. Therefore, a lane-maze with 14 lanes was printed three-dimensionally to accommodate up to 14 individual flies in a single trial. Each lane had a capillary filled with a 5% sucrose solution attached to one of the extremities, simulating a one-bottle preference test in rodents. Similarly, the test was named the one-capillary lane-maze. Male and female flies (adults, 5–6 days of age) were subjected to 0 (control), 2, 8, or 20 h of food deprivation (FD, n= 9–11/group) before testing. The one-capillary lane-maze test consisted of 10 min of habituation and 30 min of trial, which were video-recorded for further evaluation. The duration of locomotion, immobility, and grooming in the lane, capillary, or corner (zone in extreme opposition to the capillary) was scored using EthoWatcher software. A ‘preference index’ for the capillary zone was calculated as a proxy for sucrose preference. Independent of the lane zone, locomotion was the most prevalent behaviour in flies, followed by immobility and grooming. All flies were proportionally longer in the corners than in the middle of the lane, indicating that sex or FD had a minor influence on fly behaviour in the lane-maze test. The preference index revealed that flies of both sexes avoided the capillary zone, even when food-deprived. These data suggest that contrary to the primary hypothesis, the capillary was aversive to the flies. In summary, although the apparatus was suitable for high-throughput assessment of flies’ behaviours, more studies are required to develop a sucrose preference test in the lane-maze.
Keywords
Submitted date:
11/30/2022
Accepted date:
04/21/2023