Computational Neuroscience Seminar: Tiziano D'Albis

Title: The origin, inheritance, and amplification of grid-cell patterns

Abstract: Grid cells are neurons of the medial entorhinal cortex that fire according to the position of an animal in its environment. A single grid cell activates at multiple spatial locations with firing fields that form a regular triangular pattern. Grid cells are thought to support animal's navigation and spatial memory, but the mechanisms that generate their patterns are still unknown. In this talk, I present a theory that explains the emergence, inheritance, and amplification of grid-cell activity.
First, I focus on the emergence of spatial patterns. I embrace the idea that periodic representations of space could emerge via a competition between persistently-active inputs and the reluctance of a neuron to fire for long stretches of time. Building upon previous theoretical work, I propose a single-cell model that generates grid-like activity solely form spatially-irregular inputs, spike-rate adaptation, and Hebbian synaptic plasticity.
In the second part of my talk, I focus on the inheritance and amplification of grid-cell patterns. I show that grids can be inherited across neuronal populations, and that both feed-forward and recurrent connections can amplify the regularity of spatial firing. Finally, I show that a connectivity supporting these functions could self-organize in an unsupervised manner.
Altogether my work aims at understanding the fundamental principles governing the neuronal representation of space in the medial entorhinal cortex.