title: Deletion of the serotonin receptor type 7 disrupts the acquisition of allocentric but not egocentric navigation strategies in mice.
abstract: Spatial navigation is achieved through both egocentric (body-centered) and allocentric (externally-centered) strategies but decline with age, especially allocentric strategies. A better understanding of the neurobiological mechanisms underlying these strategies would allow the development of new treatments to mitigate this deterioration. Among them, the modulation of 5-HT7receptor (5-HT7R) may constitute a potential strategy. Indeed, this receptor is known to play a role in spatial navigation, however its precise role in egocentric and allocentric strategies remains unclear. Here, we first examined the effect of 5-HT7genetic invalidation (knock-out (KO) mice) in two versions of a water cross-maze task in which only egocentric or allocentric strategies were efficient to solve the task. Our results demonstrated that KO mice are able to learn an allocentric strategy. However, contrary to wild-type mice (WT mice), the acquisition rate was slower compared to the task requiring the acquisition of an egocentric strategy. Mice were then trained in a third version of the water maze, allowing the use of both egocentric and allocentric strategies. When facing conflicting spatial information, both KO and WT mice preferentially used an egocentric strategy. However, only WT mice displayed a greater latency to achieve the task. This suggests that WT mice are able to learn both information in parallel, but not KO mice (i.e. only learning an egocentric strategy). Altogether, these results provide evidence for the essential role of the 5HT7R in the acquisition of an allocentric strategy and in the ability to learn concomitantly both strategies.
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France.
authors.forename: Gregory
authors.initials: G
authors.lastname: Beaudet
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Jozet-Alves
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France.
authors.forename: Rachel
authors.initials: R
authors.lastname: Asselot
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Schumann-Bard
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Freret
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Boulouard
authors.affiliation: Normandie Univ, UNICAEN, GMPc, F-14032, Caen, France. Electronic address: eleni.paizanis@unicaen.fr.
authors.forename: Eleni
authors.initials: E
authors.lastname: Paizanis
mesh_terms: D000818:Animals; D002755:Choice Behavior; D004924:Escape Reaction; D007389:Internal-External Control; D007859:Learning Disabilities / Q000235:genetics*; D008297:Male; D018782:Maze Learning; D051379:Mice; D018345:Mice, Knockout; D011985:Receptors, Serotonin / Q000172:deficiency* / Q000235:genetics; D013028:Space Perception / Q000502:physiology*; D065854:Spatial Navigation / Q000502:physiology*; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D011985:Receptors, Serotonin; C104425:serotonin 7 receptor
keywords: 5-HT(7)R; Allocentric strategy; Egocentric strategy; Spatial cognition