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Endogenous opioids in frontal cortex of patients with Down syndrome
Risser D, You ZB, Cairns N, Herrera-Marschitz M, Seidl R, Schneider C, Terenius L, Lubec G.. Neuroscience letters, 1996-01-01
Topic: Brain proteins, microglia and lab models
The main purpose of this study was to investigate differences regarding endogenous opioids in post-mortem frontal cortex of adult patients with Down syndrome (DS), patients with Alzheimer disease (AD) and neurologically healthy persons, respectively, using specific radioimmunoassays. The results of this study show that there is an increase in the levels of leu-enkephalin and dynorphin A in the frontal cortex of patients with DS as compared to the control group. An almost identical increase was also observed when comparing patients with AD to controls. In conclusion, the results of this study suggest a relationship between elevated tissue levels of leuenkephalin and dynorphin A in cerebral cortex and cognitive impairments in patients with DS and AD.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Risser, D., You, Z. B., Cairns, N., Herrera-Marschitz, M., Seidl, R., Schneider, C., et al. (1996). Endogenous opioids in frontal cortex of patients with Down syndrome. Neuroscience letters. https://doi.org/10.1016/0304-3940(95)12275-3
Vancouver
Risser D, You ZB, Cairns N, Herrera-Marschitz M, Seidl R, Schneider C, et al. Endogenous opioids in frontal cortex of patients with Down syndrome. Neuroscience letters. 1996. doi:10.1016/0304-3940(95)12275-3. PMID: 8834106.
BibTeX
@article{risser1996-8834106,
author = {Risser, D. and You, Z. B. and Cairns, N. and Herrera-Marschitz, M. and Seidl, R. and Schneider, C. and Terenius, L. and Lubec, G.},
title = {{Endogenous opioids in frontal cortex of patients with Down syndrome}},
journal = {Neuroscience letters},
year = {1996},
doi = {10.1016/0304-3940(95)12275-3},
pmid = {8834106},
url = {https://doi.org/10.1016/0304-3940(95)12275-3}
}
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 8 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 results of this study show that there is an increase in the levels of leu-enkephalin and dynorphin A in the frontal cortex of patients with DS as compared to the control group.
- In conclusion, the results of this study suggest a relationship between elevated tissue levels of leuenkephalin and dynorphin A in cerebral cortex and cognitive impairments in patients with DS and AD.
Why it matters
Levels of leu-enkephalin and dynorphin A were increased in the frontal cortex of people with Down syndrome and people with Alzheimer's disease compared with controls. The authors suggest a relationship with cognitive impairment, but this is post-mortem tissue analysis and no treatment was tested.
Study details
- Evidence strengthLow
How this study scored 33/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomized / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Neuroscience letters) |
| Journal's citation record | 3 / 4 | Neuroscience Letters: journal h-index 267 (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 | 1 / 5 | 1996 — older than 20 years, still counted |
| 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) |
| Randomized / blinded | 0 / 2 | No randomization or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 3 / 7 | Cited 30 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.9 citations a year over 32 year(s) since 1996 |
| Impact for its field and year | 1 / 6 | Cited 0.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Gert Lübec: h-index 70 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Karolinska Institutet: institution h-index 1,477 (OpenAlex) |
| Multicenter collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 3 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 8834106) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 33 / 100 | — |
What each of these 20 components measures, and what this score is not →
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