ArticlePharmacological reports : PR2025
The influence of morphine treatment on the opioid propeptide gene expression in the forebrain of two inbred mouse strains with different sensitivity to opioids.
Article in Pharmacological reports : PR, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundC57BL/6 and DBA/2 mouse strains differ markedly in behavioral responses to acute and chronic morphine administration. Some of these disparities might be underlain by and/or correlated with different expression of the opioid propeptide genes Pdyn and Penk. The objective of our study was to characterize the influence of morphine on Pdyn and Penk expression in substance abuse-related forebrain regions of C57BL/6 and DBA/2 mice.
methodsPdyn and Penk mRNA levels were measured using in situ hybridization after acute or chronic morphine administration, and during 24-48-h withdrawal.
resultsPdyn and Penk gene expression was increased after chronic morphine and throughout withdrawal in all investigated brain regions. The changes were strain-specific in the central amygdaloid nucleus (CeA), where both genes were upregulated exclusively in C57BL/6 mice. The effect of morphine on Penk and Pdyn mRNA levels in the NAc core and shell did not significantly differ between the strains. However, trends within the data suggest greater upregulation of Pdyn in DBA/2 mice and of Penk in C57BL/6 mice. No such trends were observed in the dorsal striatum.
conclusionsOur results suggest that Penk-expressing neurons of the CeA, which are critical for some withdrawal symptoms, adapt differently to chronic morphine in C57BL/6 vs. DBA/2 mice. We discuss how this may correspond to the inter-strain disparity in the opioid withdrawal syndrome intensity. We also analyze possible causes and consequences of the presumed inter-strain differences in morphine effects within the NAc.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.