Three-Dimensional Probabilistic Maps of Mesial Temporal Lobe Structures in Children and Adolescents' Brains.

Antoine Bouyeure,Catherine Chiron,Clara Fischer,Marion Noulhiane,David Germanaud,Lucie Hertz-Pannier,Jean-Francois Mangin,Charlotte Pinabiaux,Victor Delattre,Dhaif Bekha,Denis Rivière,Julien Lefèvre

doi:10.3389/fnana.2018.00098

Abstract

The hippocampus and the adjacent perirhinal, entorhinal, temporopolar, and parahippocampal cortices are interconnected in a hierarchical MTL system crucial for memory processes. A probabilistic description of the anatomical location and spatial variability of MTL cortices in the child and adolescent brain would help to assess structure-function relationships. The rhinal sulcus (RS) and the collateral sulcus (CS) that border MTL cortices and influence their morphology have never been described in these populations. In this study, we identified the aforementioned structures on magnetic resonance images of 38 healthy subjects aged 7–17 years old. Relative to sulcal morphometry in the MTL, we showed RS-CS conformation is an additional factor of variability in the MTL that is not explained by other variables such as age, sex and brain volume; with an innovative method using permutation testing of the extrema of structures of interest, we showed that RS-SC conformation was not associated with differences of location of MTL sulci. Relative to probabilistic maps, we offered for the first time a systematic mapping of MTL structures in children and adolescent, mapping all the structures of the MTL system while taking sulcal morphology into account. Our results, with the probabilistic maps described here being freely available for download, will help to understand the anatomy of this region and help functional and clinical studies to accurately test structure-function hypotheses in the MTL during development.Free access to MTL pediatric atlas: http://neurovault.org/collections/2381/.

Highlights

The medial temporal lobe (MTL) plays a pivotal role in memory and learning
Age No age effect was found on rhinal sulcus (RS)-collateral sulcus (CS) proper conformation
Subjects were distributed into sulcal types regardless of age

Summary

Introduction

The medial temporal lobe (MTL) plays a pivotal role in memory and learning. During childhood and adolescence, memory abilities undergo a continuous development in relation to the anatomical maturation of MTL structures. Probabilistic maps have already been proposed for the HC subfields, the perirhinal cortex and the entorhinal cortex (Amunts et al, 2005; Fischl et al, 2009; Augustinack et al, 2013a; Iglesias et al, 2015; Yushkevich et al, 2015), and for sulcal morphological variants (RS and CS proper) (Huntgeburth and Petrides, 2016), probabilistic description of the anatomical variability of all MTL structures (hippocampus, adjacent cortices, and sulci) in a group of children and adolescents has not been made Such an atlas would be useful in several regards. A pediatric of all MTL structures, thereby taking into account age-related anatomical variability, would be useful to test structure-function relationships during development

Results

Discussion

Conclusion