Biology subjects

Moser, E. I.

Publications and source records attributed to Moser, E. I..

3 recordsLinked to original sources

bioRxiv2018

Object-vector coding in the medial entorhinal cortex

Mammals use distances and directions from local objects to calculate trajectories during navigation but how such vectorial operations are implemented in neural representations of space has not been determined. Here we show in freely moving mice that a population of neurons in the medial entorhinal cortex (MEC) responds specifically when the animal is at a given distance and direction from a spatially confined object. These object-vector cells are tuned similarly to a spectrum of discrete objects, irrespective of their location in the test arena. The vector relationships are expressed from the outset in novel environments with novel objects. Object-vector cells are distinct from grid cells, which use a distal reference frame, but the cells exhibit some mixed selectivity with head-direction and border cells. Collectively, these observations show that object locations are integrated in metric representations of self-location, with specific subsets of MEC neurons encoding vector relationships to individual objects.

neuroscience↗

bioRxiv2017

Head-Direction drift in rat pups is consistent with an angular path-integration process

The sense of direction is a vital computation, whose neural basis is considered to be carried out by head-direction cells. One way to estimate head-direction is by integrating head angular-velocity over time. However, this process results in error accumulation resembling a random walk, proportional to [Formula], which constitutes a mark for a path integration process. In the present study we analyzed previously recorded data to quantify the drift in head-direction cells of rat pups before and after eye-opening. We found that in rat pups before eye-opening the drift propagated as a random walk, while in rats after eye-opening the drift was lower. This suggests that a path-integration process underlies the estimation of head-direction, such that before eye-opening the head-direction system runs in an open-loop manner and accumulates error. After eye-opening, visual-input, such as arena shape, helps to correct errors and thus compute the sense of direction accurately.

bioinformatics↗

bioRxiv2017

Correlation structure of grid cells is preserved during sleep

The network of grid cells in the medial entorhinal cortex forms a fixed reference frame for mapping physical space. The mechanistic origin of the grid representation is unknown, but continuous attractor network (CAN) models explain multiple fundamental features of grid-cell activity. An untested prediction of CAN grid models is that the grid-cell network should exhibit an activity correlation structure that transcends behavioural or brain states. By recording from MEC cell ensembles during navigation and sleep, we found that spatial phase offsets of grid cells predict arousal-state-independent spike rate correlations. Similarly, state-invariant correlations between conjunctive grid-head-direction and pure head-direction cells were predicted by their head-direction tuning offsets. Spike rates of grid cells were only weakly correlated across modules, and module scale relationships disintegrated during slow-save sleep, suggesting that modules function as independent attractor networks. Collectively, our observations suggest that network states in MEC are expressed universally across brain and behaviour states.

neuroscience↗