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Temporal lobe functional activity and connectivity in young adult APOE varepsilon4 carriers
Dennis NA, Browndyke JN, Stokes J, Need A, Burke JR, Welsh-Bohmer KA, Cabeza R.. Alzheimer's & dementia : the journal of the Alzheimer's Association, 2009-09-09
Topic: Brain proteins, microglia and lab models
Background We sought to determine if the APOE epsilon4 allele influences both the functional activation and connectivity of the medial temporal lobes (MTLs) during successful memory encoding in young adults. Methods Twenty-four healthy young adults, i.e., 12 carriers and 12 noncarriers of the APOE epsilon4 allele, were scanned in a subsequent-memory paradigm, using event-related functional magnetic resonance imaging. The neuroanatomic correlates of successful encoding were measured as greater neural activity for subsequently remembered versus forgotten task items, or in short, encoding success activity (ESA). Group differences in ESA within the MTLs, as well as whole-brain functional connectivity with the MTLs, were assessed. Results In the absence of demographic or performance differences, APOE epsilon4 allele carriers exhibited greater bilateral MTL activity relative to noncarriers while accomplishing the same encoding task. Moreover, whereas epsilon4 carriers demonstrated a greater functional connectivity of ESA-related MTL activity with the posterior cingulate and other peri-limbic regions, reductions in overall connectivity were found across the anterior and posterior cortices. Conclusions These results suggest that the APOE varepsilon4 allele may influence not only functional activations within the MTL, but functional connectivity of the MTLs to other regions implicated in memory encoding. Enhanced functional connectivity of the MTLs with the posterior cingulate in young adult epsilon4 carriers suggests that APOE may be expressed early in brain regions known to be involved in Alzheimer's disease, long before late-onset dementia is a practical risk or consideration. These functional connectivity differences may also reflect pleiotropic effects of APOE during early development.
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APA 7th
Dennis, N. A., Browndyke, J. N., Stokes, J., Need, A., Burke, JR., Welsh-Bohmer, K. A., et al. (2010). Temporal lobe functional activity and connectivity in young adult APOE varepsilon4 carriers. Alzheimer's & dementia : the journal of the Alzheimer's Association. https://doi.org/10.1016/j.jalz.2009.07.003
Vancouver
Dennis NA, Browndyke JN, Stokes J, Need A, Burke JR, Welsh-Bohmer KA, et al. Temporal lobe functional activity and connectivity in young adult APOE varepsilon4 carriers. Alzheimer's & dementia : the journal of the Alzheimer's Association. 2010. doi:10.1016/j.jalz.2009.07.003. PMID: 19744893.
BibTeX
@article{dennis2010-19744893,
author = {Dennis, N. A. and Browndyke, J. N. and Stokes, J. and Need, A. and Burke, JR. and Welsh-Bohmer, K. A. and Cabeza, R.},
title = {{Temporal lobe functional activity and connectivity in young adult APOE varepsilon4 carriers}},
journal = {Alzheimer's \& dementia : the journal of the Alzheimer's Association},
year = {2010},
doi = {10.1016/j.jalz.2009.07.003},
pmid = {19744893},
url = {https://doi.org/10.1016/j.jalz.2009.07.003}
}
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 names 7 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
Key findings
- The neuroanatomic correlates of successful encoding were measured as greater neural activity for subsequently remembered versus forgotten task items, or in short, encoding success activity (ESA).
- Results In the absence of demographic or performance differences, APOE epsilon4 allele carriers exhibited greater bilateral MTL activity relative to noncarriers while accomplishing the same encoding task.
- Moreover, whereas epsilon4 carriers demonstrated a greater functional connectivity of ESA-related MTL activity with the posterior cingulate and other peri-limbic regions, reductions in overall connectivity were found across the anterior and posterior cortices.
- Conclusions These results suggest that the APOE varepsilon4 allele may influence not only functional activations within the MTL, but functional connectivity of the MTLs to other regions implicated in memory encoding.
- Enhanced functional connectivity of the MTLs with the posterior cingulate in young adult epsilon4 carriers suggests that APOE may be expressed early in brain regions known to be involved in Alzheimer's disease, long before late-onset dementia is a practical risk or consideration.
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Study details
- Evidence strengthLow
How this study scored 40/100
Published in a leading specialty journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 23 of the 58 points we could judge it on, which is 40 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Alzheimer's & dementia : the journal of the Alzheimer's Association) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| 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 | 1 / 5 | 2010 — within 20 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 | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 19744893) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 23 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 23 of the 58 points we could judge it on is 40 out of 100. |
| Total | 40 / 100 | — |
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