Morphometric Description of the Wandering Behavior inDrosophilaLarvae: Aberrant Locomotion in Na⁺and K⁺Channel Mutants Revealed by Computer-Assisted Motion Analysis

Abstract

Wandering is a simple behavior in Drosophila larvae prior to metamorphosis. Using the Dynamic Image Analysis System (DIAS) initially developed for analyzing amoeboic movements of single cells, we have analyzed videotaped behaviors of Drosophila larvae at the wandering stage. Previous studies show that mutations in the Na+ channel gene paralytic (para) cause paralysis at 29 degrees C, and mutations in the K+ channel beta subunit gene Hyperkinetic (Hk) lead to leg-shaking under ether anesthesia. The application of DIAS revealed quantifiable abnormalities in the larval locomotion of both ion channel mutants even under "permissive" conditions. Analysis of centroid movement indicates that, compared to wild type, both Hk and para larvae crawled at a slower average speed, but a similar peak instantaneous speed during a contraction cycle. Nevertheless, contraction in the body length was greater in mutants, implying a lower efficiency in conversion of muscular contraction to distance translocation. In addition, each mutant produced a characteristic crawling pattern distinct from the wild-type control. The larval crawling pattern was determined by periods of linear locomotion interposed by non-locomotive, "searching and decision-making" episodes, after which the crawling was resumed in a new direction. Our results demonstrate that mutations in single ion channel subunits resulted in stereotypic modifications in locomotion control and crawling patterns, and that DIAS is a powerful tool in revealing subtle differences in animal behavior and quantifying mutational effects on the interplay of discrete behavioral components.

Peripheral multidendritic sensory neurons are necessary for rhythmic locomotion behavior in Drosophila larvae

“…Larval crawling, used for travel across various types of terrain, is accomplished by repeated peristaltic wave-like strides (8) and involves molecules mediating neuronal signaling (9)(10)(11)(12). Whereas one study suggests that embryonic assembly of CPG for larval locomotion does not require sensory inputs, the same study reports that interference with the sensory function during embryogenesis severely disrupts the actual patterns of locomotion (13).…”

“…First, movies were analyzed by using Digital Imaging Analysis Software (DIAS) (Solltech, Oakdale, IA) as described in ref. 8. For each frame, the position of the larval centroid was determined.…”

Distinct Frequency-Dependent Regulation of Nerve Terminal Excitability and Synaptic Transmission by IA and IK Potassium Channels Revealed by Drosophila Shaker and Shab Mutations

“…Recordings of larval locomotor behavior on agar plates were performed as described previously (Wang et al, 1997;. Plates made of 0.7% agarose in distilled water were used as the locomotion substrate.…”

Quantifying subtle locomotion phenotypes of Drosophila larvae using internal structures based on FIM images

“…As reported in [25], the perimeter and length of the animals serve as an indirect readout for peristaltic movement. In a similar fashion, the area of the animals can be used to quantify the peristalsis over time [34].…”

“…First attempts were made 15 years ago by adapting a tracking program initially programmed to track cells (DIAS) [25]. Since DIAS facilitates contour based feature extraction for a single animal, even peristalsis related features could be determined based on the perimeter and length of the animal.…”