A time-stamp mechanism may provide temporal information necessary for egocentric to allocentric spatial transformations

• Published in: eLife Vol. 7
• Main Authors: Wallach, Avner, Harvey-Girard, Erik, Jun, James Jaeyoon, Longtin, André, Maler, Len
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publications Ltd 22-11-2018; eLife Sciences Publications, Ltd
• Subjects: Action Potentials - physiology; Animals; Calcium Channels, T-Type - genetics; Calcium Channels, T-Type - metabolism; Egocentrism; Electric Fish - physiology; electrosensation; Food; Models, Biological; Motion; Neurons; Neurons - physiology; Neuroscience; Pallium; path integration; renewal process; Space Perception - physiology; Spatial discrimination learning; spike frequency adaptation; Superior colliculus; Tectum; Thalamus; Thalamus - physiology; Time Factors; time-coding; Visual Pathways - physiology; Canada; United States > US; spike frequency adaptation; electrosensation; neuroscience; path integration; time-coding; renewal process; thalamus
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/elife.36769

Learning the spatial organization of the environment is essential for most animals' survival. This requires the animal to derive allocentric spatial information from egocentric sensory and motor experience. The neural mechanisms underlying this transformation are mostly unknown. We addressed this problem in electric fish, which can precisely navigate in complete darkness and whose brain circuitry is relatively simple. We conducted the first neural recordings in the
, the thalamic region exclusively connecting the
with the spatial learning circuits in the
. While tectal topographic information was mostly eliminated in preglomerular neurons, the time-intervals between object encounters were precisely encoded. We show that this reliable temporal information, combined with a speed signal, can permit accurate estimation of the distance between encounters, a necessary component of path-integration that enables computing allocentric spatial relations. Our results suggest that similar mechanisms are involved in sequential spatial learning in all vertebrates.