Young rat pups were isolated from their dams under different conditions. The endogenous opioid peptides were measured in brain regions after isolation. Because there is no uptake mechanism for peptides released at the synapse and because released peptide is rapidly degraded enzymatically, decreases in peptide levels over this time course can be interpreted as release from terminals. No change was observed in either peptide in the hypothalamus, septum, or amygdala after isolation compared with controls. Significant decreases were seen in the midbrain after isolation. A comparison of peptide levels and ultrasonic vocalizations in the pups isolated in familiar, novel, or control conditions was also performed. Enkephalin levels in the midbrain were decreased in familiar and novel conditions, but in the brainstem opioid peptides were decreased only in the familiar condition. The greater involvement of the opioid peptides in the pups isolated in familiar conditions may contribute to the ability of naltrexone to block vocalization.
Adult rats that were isolated from the mother and nest for 1 hr per day from Postnatal Day 2 to 9 were studied. Controls consisted of handled littermates as well as separate litters that were never handled. As adults, animals were given either a pharmacological challenge (1.0 or 2.0 mg/kg amphetamine) or an environmental challenge (restraint). Previously isolated animals demonstrated increased activity compared to controls at both drug doses. Similarly, isolated animals manifested exaggerated inhibition of activity after restraint. Previously isolated animals usually did not show differences compared to controls under baseline conditions (saline injection or no restraint). The neuroplastic changes that result from the neonatal experience are long lasting and appear when the system is challenged.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of Some "Cobaloxime" Derivatives: A Demonstration of "Umpolung" in the Reactivity of an Organometallic ComplexDonald L. Jameson , Joseph J. Grzybowski , Deb E. Hammels , Ronald K. Castellano , Molly E. Hoke , Kimberly Freed , Sean Basquill , Angela Mendel , and William J. Shoemaker View Author Information Gettysburg College, Department of Chemistry, Gettysburg, PA 17325-1486Cite this: J. Chem. Educ. 1998, 75, 4, 447Publication Date (Web):April 1, 1998Publication History Received3 August 2009Published online1 April 1998Published inissue 1 April 1998https://pubs.acs.org/doi/10.1021/ed075p447https://doi.org/10.1021/ed075p447research-articleACS PublicationsRequest reuse permissionsArticle Views5465Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Cobalt,Organometallic chemistry,Organometallic reactions,Reaction products,Reactivity Get e-Alerts
Ethanol was orally administered once per week to 54 gravid pigtailed macaques ( Macaca nemestrina ) in doses of 0.0, 0.3, 0.6, 1.2, 1.8, 2.5 or 4.1 gm/kg from the 1st week in gestation or in doses of 2.5, 3.3 or 4.1 gm/kg from the 5th week. Mean maternal peak plasma ethanol concentrations (MPPEC's) ranged from 24 ± 6 mg/dl at the 0.3 g/kg dose to 549 ± 71 mg/dl at the 4.1 g/kg dose. Thirty‐three live born infants were assessed for abnormalities of physical and behavioral development. Ocular pathology, neuropathologic and neurochemical assessments were done on 31 animals at 6 months postnatal age. Microphthalmia was noted in three of the 26 animals exposed to ethanol. Retinal ganglion cell loss was significantly associated with intra‐uterine ethanol exposure. Microphthalmia and retinal ganglion cell loss was observed in both the delayed and full‐gestational exposed animals. No structural anomalies were found in the brains via gross inspection or light microscopy. Chemical abnormalities in the striatal nuclei were identified. Striatal dopamine concentrations increased with increasing MPPEC exposure (0–249 mg/dl) among animals exposed weekly to ethanol throughout gestation. Striatal dopamine concentrations decreased with increasing MPPEC exposure (260–540 mg/dl) among animals whose weekly exposure to ethanol was delayed until the 5th week of gestation. The same pattern of association was also noted between MPPEC and ultrastructural alterations in the caudate nucleus. The extent of ultrastructural alterations increased with increasing MPPEC among the fullgestational exposed animals and decreased with increasing MPPEC among the delayed‐dose animals.
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