Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Spatial navigation in darkness is thought to be implemented by idiothesis, a process based on integrating the interoceptive movement-related information (path-integration). The possibility that substrate-bound external cues (e.g. floor scent marks) may contribute significantly to idiothesis was tested in a circular arena consisting of two segments: a rotating inner disk (80 cm in diameter) and a fixed outer belt (30 cm wide). Rats (n=8) searching pellets thrown on the arena floor in darkness were trained to avoid a 60o sector which was punished by moderate footshocks (place avoidance task; PA). The computer-based system tracking the rat permitted to fix the forbidden sector in an idiothetically predictable position, while putative intramaze marks were 'shuffled' by permanently changing mutual position of both arena segments. During acquisition of PA (30 min), the rats received 4.81±0.49 shocks on the stable arena and 15.02±1.13 shocks on the shuffled arena. After turning the shock off, avoidance of the forbidden sector was apparent after 30 min period on the stable arena, but on the shuffled arena, avoidance extinguished within 2 min. Path-integration thus provides reliable information for solving this spatial task in darkness only at short time periods and must by updated with exteroceptive substratal information.

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Poster Number PAstuchlik0597
Keywords: navigation, spatial, idiothesis, path-integration, rat