uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Long-term effects of short and long periods of maternal separation on brain opioid peptide levels in male Wistar rats
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
2003 (English)In: Neuropeptides, ISSN 0143-4179, E-ISSN 1532-2785, Vol. 37, no 3, 149-156 p.Article in journal (Refereed) Published
Description
Abstract [en]

Environmental manipulations early in life may induce persistent alterations in adult behaviour and physiology. The underlying neural mechanisms of these responses are not yet clear. We have previously reported long-term changes in brain opioid peptide levels in male and female Sprague-Dawley rats after short periods (15 min, known as neonatal handling) of maternal separation (MS) until weaning. To study this further, we investigated behavioural and neurochemical effects of repeated MS in male Wistar rats. The rat pups were separated from their dams in litters for either 360 min (MS360) or 15 min (MS15) daily from postnatal day 1 to 21 or exposed to normal animal facility rearing. Behavioural analysis showed that MS360 rats had increased ultrasonic calls on postnatal day 5 compared to MS15 rats, but not on postnatal day 6. Moreover, the MS360 rats had more animals with higher frequency of calls at day 5 than 6 than the MS15 rats. Analysis of the opioid peptides dynorphin B and Met-enkephalin-Arg(6)Phe(7) with radioimmunoassay 7 weeks after the MS procedure, revealed long-term neurochemical changes in several brain areas and in the pituitary gland. Immunoreactive dynorphin B and Met-enkephalin-Arg(6)Phe(7) levels were affected in the hypothalamus and dynorphin B levels in the neurointermediate pituitary lobe, amygdala, substantia nigra and the periaqueductal gray. Together, these findings show that repeated periods of MS early in life in male Wistar rats affect the development of the ultrasonic call response and induce long-lasting and possibly permanent alterations in the opioid peptide systems.

Place, publisher, year, edition, pages
2003. Vol. 37, no 3, 149-156 p.
National Category
Pharmaceutical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-64794DOI: 10.1016/S0143-4179(03)00043-XISI: 000184376500003PubMedID: 12860112OAI: oai:DiVA.org:uu-64794DiVA: diva2:92705
Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2017-11-30Bibliographically approved
In thesis
1. Maternal Separation in Rats: An Experimental Model for Long-Term Effects of Early Life Experiences on Neurochemistry, Voluntary Ethanol Intake and Exploration and Risk Assessment Behavior
Open this publication in new window or tab >>Maternal Separation in Rats: An Experimental Model for Long-Term Effects of Early Life Experiences on Neurochemistry, Voluntary Ethanol Intake and Exploration and Risk Assessment Behavior
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The period of early life is important for the development of individual brain function and behavior. Human studies have shown altered vulnerability to develop psychopathology and/or excessive drug intake, possibly leading to dependence, as a consequence of early life experiences. In the present thesis, maternal separation (MS), an experimental model for studies of early environmental influences, was used to investigate long-term effects on neurochemistry, voluntary ethanol intake and exploration and risk assessment behavior in rats. Rat pups were assigned to one of three different rearing conditions: daily 15 min (MS15) or 360 min (MS360) of MS and normal animal facility rearing (AFR) during the first three weeks of life. Measurements of adult endogenous opioid peptide levels, opioid- and dopamine receptor density revealed minor MS-induced effects on the opioid system whereas interesting alterations were found in dopamine receptor density. Long-term effects on voluntary ethanol intake showed distinct MS-induced alterations in male Wistar and ethanol-preferring AA (Alko, Alcohol) rats. Female Wistar rats were unaffected, indicating sex differences in the effects of MS on ethanol intake. Male MS15 rats generally had a slower acquisition phase and a low subsequent ethanol intake whereas male MS360 rats had a high ethanol intake. MS15 is therefore suggested to protect against a high voluntary ethanol intake in male rats whereas MS360 may serve as a risk factor. The recently established concentric square field test indicated alterations in risk assessment as well as an increased exploratory drive and somewhat higher risk-taking behavior in adult MS360 rats, while minor effects were seen in MS15 rats. Altogether, these results demonstrate that environmental influences during the period of early life can have long-term effects on neurochemistry and behavior. Of special interest is the finding that MS altered the inherited high ethanol intake in adult ethanol-preferring AA rats.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2004. 81 p.
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, ISSN 0282-7484 ; 313
Keyword
Pharmaceutical pharmacology, Handling, Maternal Deprivation, Environment, Opioids, Dopamine, Alcohol, Stress, Concentric Square Field, Open Field, Elevated Plus-maze, Farmaceutisk farmakologi
National Category
Pharmacology and Toxicology
Identifiers
urn:nbn:se:uu:diva-4465 (URN)91-554-6009-7 (ISBN)
Public defence
2004-09-24, B42, BMC, Husargatan 3, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2004-09-03 Created: 2004-09-03 Last updated: 2009-06-02Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Authority records BETA

Nylander, Ingrid

Search in DiVA

By author/editor
Roman, ErikaNylander, Ingrid
By organisation
Department of Pharmaceutical Biosciences
In the same journal
Neuropeptides
Pharmaceutical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 311 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf