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Functional Connectivity between the Resting-State Olfactory Network and the Hippocampus in Alzheimer's Disease
Lu J, Testa N, Jordan R, Elyan R, Kanekar S, Wang J, Eslinger P, Yang QX et al.. Brain sciences, 2019-11-25
Topic: Amyloid, tau and blood-test diagnosis
Olfactory impairment is associated with prodromal Alzheimer's disease (AD) and is a risk factor for the development of dementia. AD pathology is known to disrupt brain regions instrumental in olfactory information processing, such as the primary olfactory cortex (POC), the hippocampus, and other temporal lobe structures. This selective vulnerability suggests that the functional connectivity (FC) between the olfactory network (ON), consisting of the POC, insula and orbital frontal cortex (OFC) (Tobia et al., 2016), and the hippocampus may be impaired in early stage AD.
Key findings
- AD pathology is known to disrupt brain regions instrumental in olfactory information processing, such as the primary olfactory cortex (POC), the hippocampus, and other temporal lobe structures.
- This selective vulnerability suggests that the functional connectivity (FC) between the olfactory network (ON), consisting of the POC, insula and orbital frontal cortex (OFC) (Tobia et al., 2016), and the hippocampus may be impaired in early stage AD.
- Yet, the development trajectory of this potential FC impairment remains unclear.
- Here, we used resting-state functional magnetic resonance imaging (rs-fMRI) data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to investigate FC changes between the ON and hippocampus in four groups: aged-matched cognitively normal (CN), early mild cognitive impairment (EMCI), late mild cognitive impairment (LMCI), and AD.
Why it matters
This study examined functional connectivity between the olfactory network and the hippocampus, based on the idea that this connection may be impaired in early Alzheimer's disease. It is about understanding brain changes, not treating, curing, or preventing the disease.
Study details
- Evidence strengthLow
How this study scored 41/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Brain sciences) |
| Journal's citation record | 1 / 4 | Brain Sciences: journal h-index 115 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2019 — within 10 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 4 / 7 | Cited 67 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 7.4 citations a year over 9 year(s) since 2019 |
| Impact for its field and year | 3 / 6 | Cited 3.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 2 / 4 | Cited 30 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Prasanna Karunanayaka: h-index 23 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Pennsylvania State University: institution h-index 1,397 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 31775369) |
| Free to read | 2 / 2 | Free to read |
| Total | 41 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Lu, J., Testa, N., Jordan, R., Elyan, R., Kanekar, S., Wang, J., et al. (2019). Functional Connectivity between the Resting-State Olfactory Network and the Hippocampus in Alzheimer's Disease. Brain sciences. https://doi.org/10.3390/brainsci9120338
Vancouver
Lu J, Testa N, Jordan R, Elyan R, Kanekar S, Wang J, et al. Functional Connectivity between the Resting-State Olfactory Network and the Hippocampus in Alzheimer's Disease. Brain sciences. 2019. doi:10.3390/brainsci9120338. PMID: 31775369.
BibTeX
@article{lu2019-31775369,
author = {Lu, J. and Testa, N. and Jordan, R. and Elyan, R. and Kanekar, S. and Wang, J. and Eslinger, P. and Yang, Q. X. and others},
title = {{Functional Connectivity between the Resting-State Olfactory Network and the Hippocampus in Alzheimer's Disease}},
journal = {Brain sciences},
year = {2019},
doi = {10.3390/brainsci9120338},
pmid = {31775369},
url = {https://doi.org/10.3390/brainsci9120338}
}
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