William M. Sheeran, Omar J. Ahmed. The neural circuitry supporting successful spatial navigation despite variable movement speeds. Neuroscience & Biobehavioral Reviews, Volume 108, 2020, Pages 821-833.

Highlights
• Spatial memories remains stable despite dramatic changes in running speed.

• Neuronal firing rates and temporal dynamics are both altered by running speed.

• Speed-dependent neural codes may help stabilize spatial memories.

• Speed codes altered by stimulation of medial septum and brainstem locomotor regions.

• Critical to identify which region provides the earliest prediction of speed change.

Abstract
“Ants who have successfully navigated the long distance between their foraging spot and their nest dozens of times will drastically overshoot their destination if the size of their legs is doubled by the addition of stilts. This observation reflects a navigational strategy called path integration, a strategy also utilized by mammals. Path integration necessitates that animals keep track of their movement speed and use it to precisely and instantly modify where they think they are and where they want to go. Here we review the neural circuitry that has evolved to integrate speed and space. We start with the rate and temporal codes for speed in the hippocampus and work backwards towards the motor and sensory systems. We highlight the need for experiments designed to differentiate the respective contributions of motor efference copy versus sensory inputs. In particular, we discuss the importance of high-resolution tracking of the latency of speed-encoding as a precise way to disentangle the sensory versus motor computations that enable successful spatial navigation at very different speeds.”

William M. Sheeran, Omar J. Ahmed. The neural circuitry supporting successful spatial navigation despite variable movement speeds. Neuroscience & Biobehavioral Reviews, Volume 108, 2020, Pages 821-833.