Navigable Space and Traversable Edges Differentially Influence Reorientation in Sighted and Blind Mice

Abstract

Reorientation enables navigators to regain their bearings after becoming lost. Disoriented individuals primarily reorient themselves using the geometry of a layout, even when other informative cues, such as landmarks, are present. Yet the specific strategies that animals use to determine geometry are unclear. Moreover, because vision allows subjects to rapidly form precise representations of objects and background, it is unknown whether it has a deterministic role in the use of geometry. In this study, we tested sighted and congenitally blind mice ( Ns = 8–11) in various settings in which global shape parameters were manipulated. Results indicated that the navigational affordances of the context—the traversable space—promote sampling of boundaries, which determines the effective use of geometric strategies in both sighted and blind mice. However, blind animals can also effectively reorient themselves using 3D edges by extensively patrolling the borders, even when the traversable space is not limited by these boundaries.

Defibrinogenation Ameliorates Retinal Microgliosis and Inflammation in A CX3CR1-Independent Manner

“…To assess visual acuity, a two-choice discrimination task was utilized ( Figure 5A and B ) as previously described ( Normandin et al, 2022 ). To establish an initial baseline readout of visual acuity, naïve CX3CR1-WT and CX3CR1-KO mice were assessed under infrared and visible light conditions.…”

“…However, these responses to visual stimuli do not provide readouts correlating to cortical function and integrated visual performance ( Busse et al, 2011 ; Storchi et al., 2019 ). To address limitations of reflex-based visual function tests, we applied a two-choice visual acuity test ( Keinath et al, 2017 ; Normandin et al, 2022 ). Our results show that both systemic endotoxemia and 10-week hyperglycemia resulted in significantly compromised visual function.…”

“…A visual acuity task was conducted as previously described ( Normandin et al, 2022 ) in a rectangular plexiglass apparatus (13 inches × 9 inches) with two plastic medicine cups containing cumin-scented wood chip bedding embedded in opposite sides of the chamber floor ( Keinath et al, 2017 ). The chamber featured one short wall with 4 diffuse black stripes, and the other with 2 diffuse black stripes.…”

“…Mice were trained to dig for a food reward by housing them individually and providing them with a 30-mL capacity reward cup containing 1-2 g of a food pellet alongside a small chocolate cereal crumb reward (Cocoa Krispies, Kellogg's) buried beneath fine-grain wood chip bedding (Sani-Chip IRR, LabSupply) mixed with cumin to eliminate olfactory cues. A visual acuity task was conducted as previously described (Normandin et al, 2022) in a rectangular plexiglass apparatus (13 inches × 9 inches) with two plastic medicine cups containing cumin-scented wood chip bedding embedded in opposite sides of the chamber floor (Keinath et al, 2017). The chamber featured one short wall with 4 diffuse black stripes, and the other with 2 diffuse black stripes.…”

Distinct Neural Mechanisms for Heading Retrieval and Context Recognition in the Hippocampus During Spatial Reorientation

“…View matching theory suggests that navigators identify targets by matching the current panoramic view of a location with a stored representation of the goal area (Collett & Collett, 2002;Sheynikhovich et al, 2009;Sturzl et al, 2008), a process that relies on visual recognition rather than retrieval of a cognitive map of the layout. This theory can account for geometric errors and has gained support from research with ants and chicks (Pecchia & Vallortigara, 2010bWystrach et al, 2011), but it has been challenged by findings showing that children can reorient using geometry regardless of the contextual viewpoint (Huttenlocher & Vasilyeva, 2003) and that visually impaired subjects can reorient using geometry (Landau et al, 1981;Normandin et al, 2022;Sovrano et al, 2018). The geometric module view, on the other hand, proposes that navigators reorient based solely on a cognitive representation of environmental geometry that is impermeable to non-geometric information (Gallistel, 1990;Hermer & Spelke, 1996;Lee & Spelke, 2010a.…”