Previousstudieshavedemonstratedthatdoublecortin-positiveimmatureneuronsexistpredominantlyinthesuperficiallayerofthecerebralcortexofadultmammalssuchasguineapigs,andtheseneuronsexhibitveryweakpropertiesofself-proliferationduringadulthoodunderphysiologicalconditions.Toverifywhetherenvironmentalenrichmenthasanimpactontheproliferationandmaturationoftheseimmatureneuronsintheprefrontalcortexofadultguineapigs,healthyadultguineapigsweresubjectedtoshort-termenvironmentalenrichment.Animalswereallowedtoplaywithvariouscognitiveandphysicalstimulatingobjectsoveraperiodof2weeks,twiceperday,for60minuteseach.Immunofluorescencestainingresultsindicatedthatthenumberofdoublecortin-positivecellsinlayerIIoftheprefrontalcortexwassignificantlyincreasedaftershort-termenvironmentalenrichmentexposure.Inaddition,thesedoublecortin-positivecellsco-expressed5-bromo-2-deoxyuridine(amarkerofcellproliferation),c-Fos(amarkerofcellviability)andNeuN(amarkerofmatureneurons).Experimentalfindingsshowedthatshort-termenvironmentalenrichmentcaninduceproliferation,activationandmaturationofdoublecortin-positivecellsinlayerIIoftheprefrontalcortexofadultguineapigs.
