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
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 thes...
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Uppsala universitet, Institutionen för farmaceutisk biovetenskap
2004
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ndltd-UPSALLA1-oai-DiVA.org-uu-44652013-01-08T13:05:12ZMaternal Separation in Rats : An Experimental Model for Long-Term Effects of Early Life Experiences on Neurochemistry, Voluntary Ethanol Intake and Exploration and Risk Assessment BehaviorengRoman, ErikaUppsala universitet, Institutionen för farmaceutisk biovetenskapUppsala : Acta Universitatis Upsaliensis2004Pharmaceutical pharmacologyHandlingMaternal DeprivationEnvironmentOpioidsDopamineAlcoholStressConcentric Square FieldOpen FieldElevated Plus-mazeFarmaceutisk farmakologiPharmaceutical pharmacologyFarmaceutisk farmakologiThe 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. Doctoral thesis, comprehensive summaryinfo:eu-repo/semantics/doctoralThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4465urn:isbn:91-554-6009-7Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, 0282-7484 ; 313application/pdfinfo:eu-repo/semantics/openAccess |
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NDLTD |
language |
English |
format |
Doctoral Thesis |
sources |
NDLTD |
topic |
Pharmaceutical pharmacology Handling Maternal Deprivation Environment Opioids Dopamine Alcohol Stress Concentric Square Field Open Field Elevated Plus-maze Farmaceutisk farmakologi Pharmaceutical pharmacology Farmaceutisk farmakologi |
spellingShingle |
Pharmaceutical pharmacology Handling Maternal Deprivation Environment Opioids Dopamine Alcohol Stress Concentric Square Field Open Field Elevated Plus-maze Farmaceutisk farmakologi Pharmaceutical pharmacology Farmaceutisk farmakologi Roman, Erika 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 |
description |
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. |
author |
Roman, Erika |
author_facet |
Roman, Erika |
author_sort |
Roman, Erika |
title |
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 |
title_short |
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 |
title_full |
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 |
title_fullStr |
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 |
title_full_unstemmed |
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 |
title_sort |
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 |
publisher |
Uppsala universitet, Institutionen för farmaceutisk biovetenskap |
publishDate |
2004 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4465 http://nbn-resolving.de/urn:isbn:91-554-6009-7 |
work_keys_str_mv |
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