Functional connectivity changes in the entorhinal cortex of taxi drivers.

Limin Peng,Qiang Liu,Hui Shen,Jian Qin,Lubin Wang,Hong Li,Ling‐Li Zeng,Huaze Xu,Dewen Hu

doi:10.1002/brb3.1022

Abstract

IntroductionAs a major interface between the hippocampus and the neocortex, the entorhinal cortex (EC) is widely known to play a pivotal role in spatial memory and navigation. Previous studies have suggested that the EC can be divided into the anterior‐lateral (alEC) and the posterior‐medial subregions (pmEC), with the former receiving object‐related information from the perirhinal cortex and the latter receiving scene‐related information from the parahippocampal cortex. However, the functional connectivity maps of the EC subregions in the context of extensive navigation experience remain elusive. In this study, we analyzed the functional connectivity of the EC in subjects with long‐term navigation experience and aimed to find the navigation‐related change in the functional properties of the human EC.MethodsWe investigated the resting‐state functional connectivity changes in the EC subregions by comparing the EC functional connectivity maps of 20 taxi drivers with those of 20 nondriver controls. Furthermore, we examined whether the functional connectivity changes of the EC were related to the number of taxi driving years.ResultsSignificantly reduced functional connectivity was found in the taxi drivers between the left pmEC and the right anterior cingulate cortex (ACC), right angular gyrus, and bilateral precuneus as well as some temporal regions, and between the right pmEC and the left inferior temporal gyrus. Notably, the strength of the functional connectivity between the left pmEC and the left precuneus, as well as the right ACC, was negatively correlated with the years of taxi driving.ConclusionThis is the first study to explore the impact of long‐term navigation experience on the connectivity patterns of the EC, the results of which may shed new light on the potential influence of extensive navigational training on the functional organization of the EC in healthy human brains.

Highlights

As a major interface between the hippocampus and the neocortex, the entorhinal cortex (EC) is widely known to play a pivotal role in spatial memory and navigation
The EC is located on the ventromedial surface of the temporal lobe together with the adjacent perirhinal cortex (PRC) and parahippocampal cortex (PHC), and these regions form a neural circuit that is essential for the formation and retrieval of spatial memory (Brown & Aggleton, 2001; Eichenbaum, Yonelinas, & Ranganath, 2007; Ranganath, 2010; Ranganath & Ritchey, 2012; Suzuki & Howard, 2010)
In this study, choosing the well-established bilateral alEC and pmEC regions (Maass et al, 2015) as regions of interest (ROI), we examined the functional connectivity changes in the EC subregions by comparing the EC functional connectivity maps in 20 licensed taxi drivers with those of 20 control subjects with no driving experience; the taxi drivers were chosen to ensure a consistent level of driving in the environment

Summary

| INTRODUCTION

As is well-known, driving a car is a complex behavior that involves environmental perception, action execution, and route navigation. The key role of the hippocampus in spatial memory and navigation is well-established (Maguire et al, 1998), and structural changes in the hippocampus have been found in people with a high dependence on navigational skills (Maguire et al, 2000), which reflects the capability for local plastic change in the structures of the human brain in response to environmental demands. In this region, the entorhinal cortex (EC), as the major interface connecting the neocortex and hippocampus (Muñoz & Insausti, 2005), has received a large amount of attention in recent years. We examined whether the functional connectivity changes of the EC were related to the number of years the taxi drivers had been driving

| MATERIALS AND METHODS

Findings

| DISCUSSION

| CONCLUSION