Movement characteristics support a role for dead reckoning in organizing exploratory behavior

Abstract

Rat exploration is an organized series of trips. Each exploratory trip involves an outward tour from the refuge followed by a return to the refuge. A tour consists of a sequence of progressions with variable direction and speed concatenated by stops, whereas the return consists of a single direct progression. We have argued that processing self-movement information generated on the tour allows a rat to plot the return to the refuge. This claim has been supported by observing consistent differences between tour and return segments independent of ambient cue availability; however, this distinction was based on differences in movement characteristics derived from multiple progressions and stops on the tour and the single progression on the return. The present study examines movement characteristics of the tour and return progressions under novel-dark and light conditions. Three novel characteristics of progressions were identified: (1) linear speeds and path curvature of exploratory trips are negatively correlated, (2) tour progression maximum linear speed and temporal pacing varies as a function of travel distance, and (3) return progression movement characteristics are qualitatively different from tour progressions of comparable length. These observations support a role for dead reckoning in organizing exploratory behavior.

The Head-Direction Signal Plays a Functional Role as a Neural Compass during Navigation

“…As in the recording experiment, animals were trained and tested under both standard (with a prominent visual cue) and dark conditions; these conditions were maintained over the entire duration of each training or testing session. As reported previously [34,36] animals were less accurate at homing under dark conditions compared to light conditions (ANOVA, main effect of condition; homing error: F 1,540 = 11.224, p = 0.0009; homing circuity: F 1,539 = 31.463, p < 10 −7 ). During optogenetic testing, NPH→DTN photoinhibition (on a 10 sec on/1 sec off cycle throughout the entire session) did not affect animals' ability to accurately direct their homing paths toward the refuge under standard, well-illuminated conditions, but impaired their homing in the absence of visual cues (Fig.…”

“…6B), suggesting that the manipulation of the HD signal stability was selective to the angular component of their navigational response. Previous work in the food-carrying task has also shown that rats are able to modulate their homing path speeds as a function of the distance they must travel, such that the point of greatest velocity falls near the midpoint of their homing path [36]. We therefore performed a kinematic analysis on the rats' return trips to the refuge in order to assess their ability to perform linear distance estimation.…”

Development of site fidelity in the nocturnal amblypygid, Phrynus marginemaculatus

“…These differences are well documented across taxa, including arachnids (Seyfarth and Barth 1972;Seyfarth et al 1982), hymenopterans Wehner 1988, 1994), decapods (Layne et al 2003a, b;Kamran and Moore 2015), and mammals (Etienne et al 1996;Etienne and Jeffery 2004;Wallace et al 2006). In particular, animals walk slowly and their paths are more sinuous on outbound journeys while inbound paths are fast, straight, and highly directed along an integrated homing vector.…”

Hippocampal damage produces retrograde but not anterograde amnesia for a cued location in a spontaneous exploratory task in rats

“…On an open field, rats will make wandering excursions from a cued home base, after which they will return to the home base in a direct and rapid manner (Wallace et al, 2006). Over the course of an entire trial, rats may make several of these exploratory movements, each followed by a direct return trip.…”

“…Direct trips, defined as distinctive rapid crossing of the table toward the cue location (Wallace et al, 2006), were also used as a behavioral measure. On an open field, rats will make wandering excursions from a cued home base, after which they will return to the home base in a direct and rapid manner (Wallace et al, 2006).…”