Fimbria-Fornix Volume Is Associated With Spatial Memory and Olfactory Identification in Humans

Front Syst Neurosci. 2020 Jan 14:13:87. doi: 10.3389/fnsys.2019.00087. eCollection 2019.

Abstract

White matter pathways that surround the hippocampus comprise its afferent and efferent connections, and are therefore crucial in mediating the function of the hippocampus. We recently demonstrated a role for the hippocampus in both spatial memory and olfactory identification in humans. In the current study, we focused our attention on the fimbria-fornix white matter bundle and investigated its relationship with spatial memory and olfactory identification. We administered a virtual navigation task and an olfactory identification task to 55 young healthy adults and measured the volume of the fimbria-fornix. We found that the volume of the right fimbria-fornix and its subdivisions is correlated with both navigational learning and olfactory identification in those who use hippocampus-based spatial memory strategies, and not in those who use caudate nucleus-based navigation strategies. These results are consistent with our recent finding that spatial memory and olfaction rely on similar neural networks and structures.

Keywords: fimbria-fornix; hippocampus; navigation; olfaction; spatial memory; white matter.