Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2020.03.13.990572

Differential brain activity in visuo-perceptual regions during landmark-based navigation in young and healthy older adults

Ramanoël, S.·Durteste, M.·Becu, M.·Habas, C.·Arleo, A.
View original source ↗Export metadata ↓

Abstract

Older adults exhibit prominent impairments in their capacity to navigate, reorient in unfamiliar environments or update their path when faced with obstacles. This decline in navigational capabilities has traditionally been ascribed to memory impairments and dysexecutive function whereas the impact of visual aging has often been overlooked. The ability to perceive visuo-spatial information such as salient landmarks is essential to navigate in space efficiently. To date, the functional and neurobiological factors underpinning landmark processing in aging remain insufficiently characterized. To address this issue, this study used functional magnetic resonance imaging (fMRI) to investigate the brain activity associated with landmark-based navigation in young and healthy older participants. Twenty-five young adults (=25.4 years, {sigma}=4.7; 7F) and twenty-one older adults (=73.0 years, {sigma}=3.9; 10F) performed a virtual navigation task in the scanner in which they could only orient using salient landmarks. The underlying whole-brain patterns of activity as well as the functional roles of scene-selective regions, the parahippocampal place area (PPA), the occipital place area (OPA), and the retrosplenial cortex (RSC) were analyzed. We found that older adults navigational abilities were diminished compared to young adults and that the two age groups relied on distinct navigational strategies to solve the task. Better performance during landmark-based navigation was found to be associated with increased neural activity in an extended neural network comprising several cortical and cerebellar regions. Direct comparisons between age groups further revealed that young participants had enhanced anterior temporal activity. In addition, young adults only were found to recruit occipital areas corresponding to the cortical projection of the central visual field during landmark-based navigation. The region-of-interest analysis revealed increased OPA activation in older adult participants. There were no significant between-group differences in PPA and RSC activations. These results hint at the possibility that aging diminishes fine-grained information processing in occipital and temporal regions thus hindering the capacity to use landmarks adequately for navigation. This work helps towards a better comprehension of the neural dynamics subtending landmark-based navigation and it provides new insights on the impact of age-related visuo-spatial processing changes on navigation capabilities.

Source connections

Explore related subjects

neurosciencePreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ramanoël, S., Durteste, M., Becu, M., Habas, C., Arleo, A.. 2020-03-15. Differential brain activity in visuo-perceptual regions during landmark-based navigation in young and healthy older adults. https://doi.org/10.1101/2020.03.13.990572

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Feasible closed-loop stimulation for neural latent dynamics control

Modern neuroscience benefits from powerful computational and experimental methods for studying neural populations, including latent dynamics models that predict behavior with few dimensions. But despite their explanatory utility, latent factors are seldom targeted explicitly with experimental perturbations, leaving causal relationships to behavior and inferred dynamical landscapes untested. A promising solution is closed-loop, multi-channel optogenetic control, which, when paired with model predictions, could steer neural trajectories in real time--a feat impossible for traditional, hand-designed stimulation. However, because closed-loop latent control has not been demonstrated in vivo, the hardware and software requirements remain unclear--particularly the necessary stimulation dimensionality and how limited resources such as implant volume and bandwidth should be allocated between stimulation and recording capabilities. Preliminary experiments would thus help guide ongoing technological development. As large-scale exploration of these design spaces in vivo is prohibitively expensive, we conducted a high-throughput simulation survey using biophysically grounded spiking neural networks. We found that low-dimensional actuation is sufficient: in the reference configuration, ~20% of the stimulation channels achieved ~85% of peak control performance, far fewer than the number of neurons. Furthermore, allocating channels roughly equally between stimulation and recording optimized behavioral control, whereas pairing many electrodes with a single light source--the prevailing practice in experimental labs--performed poorly. Even without heavily optimizing modeling or control, we obtained >60% tracking error reduction and >90% evoked behavior accuracy on average for optimal channel counts. These results held across extensive parameter variations, suggesting that closed-loop latent control is feasible with accessible channel counts and establishing design principles for future tool development and in vivo experiments.

neuroscience↗
bioRxiv2026

Identification of Kinome Biomarkers and Therapeutic Rescue in cGMP-Linked Retinal Degeneration

Inherited retinal degenerations, such as Retinitis Pigmentosa (RP) and Leber's congenital amaurosis (LCA), are major causes of progressive and irreversible vision loss. The large number of genes associated with these disorders makes their clinical and molecular characterization difficult, while systemic biomarkers for disease progression or treatment response remain limited. These challenges were addressed by targeting cGMP-associated mechanisms shared by RP and LCA and integrating systemic biomarker profiling with retinal outcomes. Kinase activity analysis (kinome analysis) in peripheral blood mononuclear cells distinguished healthy and diseased states and captured therapy-associated signatures in rd10 mice treated with LP-CN03, a liposomal formulation of the cGMP analog CN03. This first systemic analysis in a therapeutically responsive animal model highlights kinome analysis as a potential translational readout. Given shared cGMP signaling in RP and AIPL1-associated LCA, LP-CN03's therapeutic potential was further evaluated in a new CRISPR-Cas9-generated Aipl1-/- mouse model. Treatment with LP-CN03 preserved retinal structure and function, as shown by electroretinography, longitudinal optical coherence tomography, fundus imaging, optomotor testing, and photoreceptor-specific gene expression. Together, these findings provide independent in vivo evidence for the neuroprotective effect of LP-CN03 in both cGMP-related RP and LCA, also highlighting the translational value of kinome profiling.

neuroscience↗
bioRxiv2026

Shikonin alleviates bone cancer pain through suppression of spinal IGF2-associated p38 MAPK signaling

Background Bone cancer pain (BCP) is a debilitating complication of advanced cancer that substantially impairs physical function and emotional wellbeing. Current pharmacological treatments often provide incomplete analgesia and may be limited by adverse effects. Shikonin, a bioactive naphthoquinone derived from Lithospermum erythrorhizon, exhibits analgesic and anti inflammatory activities, but its effects and underlying mechanisms in BCP remain unclear. Methods A rat model of BCP was established by intratibial inoculation of luciferase labeled MADB106 cells. The analgesic and behavioral effects of intrathecal Shikonin were evaluated using mechanical and thermal nociceptive assays, CatWalk gait analysis, the open field test (OFT), elevated plus maze (EPM), light/dark box (LDB) test, and rotarod testing. Bioluminescence imaging and hematoxylin eosin staining were used to characterize tumor development and bone pathology. Spinal dorsal horn transcriptomic sequencing was performed to identify candidate molecular pathways. Western blotting, quantitative PCR, and ELISA were used to examine IGF2 associated p38 MAPK signaling and proinflammatory cytokines. The functional involvement of IGF2 and p38 associated signaling was further evaluated using intrathecal IGF2 siRNA and the p38 inhibitor Adezmapimod (SB203580). Results Intrathecal Shikonin produced dose and time dependent antinociceptive effects in BCP rats, with an estimated ED50 of 29.80 g/kg, and did not produce an apparent impairment of rotarod performance. Shikonin also improved gait abnormalities and pain related anxiety like behaviors. Transcriptomic analysis identified Igf2 as a candidate gene responsive to Shikonin treatment, and spinal IGF2 and p38 phosphorylation were increased during BCP development. Shikonin significantly reduced IGF2 expression and p38 phosphorylation in the spinal dorsal horn, accompanied by decreased IL 6, IL 1{beta};, and TNF ; expression in spinal tissue. IGF2 knockdown reproduced the analgesic and behavioral effects of Shikonin and reduced p38 phosphorylation, whereas p38 inhibition reproduced key behavioral effects without a marked change in IGF2 expression. Combined treatment with Shikonin and either IGF2 knockdown or p38 inhibition produced no significant additional behavioral benefit. Conclusion Intrathecal Shikonin alleviates nociceptive hypersensitivity, functional impairment, and pain related anxiety like behaviors in rats with MADB106 induced BCP. The phenocopying and non additive effects of IGF2 knockdown and p38 inhibition support the involvement of an IGF2 associated p38 MAPK signaling axis in the analgesic actions of Shikonin.

neuroscience↗