Recruitment of grid-like responses in human entorhinal and piriform cortices by odor landmark-based navigation

The spatial periodic computation of hippocampus-entorhinal circuit in navigation

“…1f, 5-round: t(9) < 1, 7-round: t(9) < 1). These results confirmed the involvement of entorhinal grid cells in the object space where the object-matching task occurred, consistent with previous findings (e.g., Doeller et al, 2010, Constantinescu et al, 2016Bao et al, 2019;Wagner et al, 2023;Raithel et al, 2023).…”

“…Fortunately, the orientation and spacing of grid cells remain almost invariant at populational level (Hafting et al, 2005;Stensola et al, 2015;Krupic et al, 2015;Gardner et al, 2022). If the 6-fold periodicity of grid cell populations could be detected by fMRI (Doeller et al, 2010;Constantinescu et al, 2016;Bao et al, 2019;Wagner et al, 2023;Raithel et al, 2023), it is possible that spatial periodicity may also be present in the hippocampus at the population level during navigation. 4 To investigate this, we developed an object matching task, which required participants to morph the object variants by button press to match the target prototype by navigating in a 2-dimensional object space (Fig.…”

The human sense of smell in spatial orientation: A state-of-the-art review.

“…In humans, recent studies have uncovered olfactory lateralization and even gridlike codes: Dikeçligil et al (2023) demonstrated distinct stimuli arising from the two nostrils in the piriform cortex without integration; Bao et al (2019) illustrated gridlike representations in functional magnetic resonance imaging responses in the entorhinal cortex and ventromedial prefrontal cortex during navigation, scaled with behavioral performance across participants. Raithel et al (2023) identified gridlike responses in functional magnetic resonance imaging data collected during an olfactory navigation task in the entorhinal and piriform cortices, attuned to the same grid orientation. These studies suggest the existence of a distinct and specialized olfactory grid network capable of processing odor information across nostrils within a single inhalation.…”

“…Taken together, we consider the following studies as being the most prominent and representative in olfactory navigation and landmark-based wayfinding research: Porter et al (2007), Koutsoklenis and Papadopoulos (2011b), Moessnang et al (2011), Jacobs et al (2015), Dahmani et al (2018), Raithel et al (2023) and several studies by our research group (including Arena & Hamburger, 2023; Hamburger & Knauff, 2019; Schwarz & Hamburger, 2024).…”

“…In their functional magnetic resonance imaging study, Raithel et al (2023) incorporated various measures, including odor ratings for intensity, pleasantness, and familiarity, an odor naming task, a four-alternative forced-choice task (similar to the one described by Dahmani et al, 2018 above), and an odor navigation task. The odor stimuli comprised eight scents derived from either essential oils diluted in mineral oil or natural products, administered to participants through a custom-built olfactometer.…”