D-066 | Is the dentate gyrus the core of the hippocampal allocentric spatial navigation?

Cognition, Behavior, and Memory
Author: Natalia Soldi | Email: natalia.soldi@gmail.com

Natalia Soldi^1°, Joaquín A. Quintana^2°, Sabrina Benas^3°,  Emilio Kropff^3°, Alejandro F. Schinder^1°, Maria Soledad Esposito^2°, Verónica C. Piatti^1°

^1° Laboratorio de Plasticidad Neuronal – Fundación Instituto Leloir – Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)- CONICET
^2° Laboratorio de Neurobiología del Movimiento – Departamento de Física Médica – Centro Atómico Bariloche – Comisión Nacional de Energía Atómica (CNEA) – CONICET
^3° Laboratorio de Fisiología y Algoritmos del Cerebro – Fundación Instituto Leloir – Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)- CONICET

In nature, actions such as foraging, feeding and hiding safely are daily requirements for survival. In a changing world, flexible behaviors are necessary to execute fast adaptive responses. Cognitive flexibility is the ability to solve new situations based on knowledge from previous experiences and a good approach to test it in all motile animals is spatial navigation. The animal location in a particular place could be established on the relative metric differences between the environmental sensorial cues (allocentric) or based on to the relative positions of those same cues with itself (egocentric). While the first reference frame is flexible, the second one is inflexible because it requires new learning each time the familiar environment changes. The hippocampal formation has been implicated in the allocentric and also in the egocentric navigation when a sequence of places has to be learnt to arrive to one goal location. However, it is unknown which strategy is the dentate gyrus hippocampal region good for. We found that this region was critical when a goal-guided spatial task required flexibility using a chemogenetic inhibition approach in mice. In addition, dentate gyrus was not necessary for the learning of trajectories to the goal. Bearing this in mind, we are now analyzing the navigation strategies mice with or without dentate gyrus inhibition used to reach their goal. We speculate the dentate gyrus could be a core of the hippocampal system for allocentric navigation.