Animals, NewbornCell DifferentiationAgingGene Expression Regulation, DevelopmentalNeuronsMice, Inbred C57BLImmunohistochemistryRNA, MessengerMuscle DevelopmentRats, Sprague-DawleyMice, TransgenicMice, KnockoutIn Situ HybridizationCells, CulturedPregnancyNerve Tissue ProteinsSynapsesBrain StemBrainAge FactorsCerebellumRats, WistarCerebral CortexCell CountTime FactorsSomatosensory CortexHippocampusPatch-Clamp TechniquesTranscription Factorsgamma-Aminobutyric AcidStem CellsSynaptic TransmissionSignal TransductionExcitatory Postsynaptic PotentialsReceptors, N-Methyl-D-AspartateSpinal CordGene Expression RegulationCell DivisionMolecular Sequence DataEmbryo, MammalianCell ProliferationCell LineEmbryonic and Fetal DevelopmentCell LineagePhenotypeTestisPostnatal CareReverse Transcriptase Polymerase Chain ReactionDNA-Binding ProteinsBase SequenceGene ExpressionAction PotentialsHomeodomain ProteinsOvernutritionFetusTretinoinPrenatal Exposure Delayed EffectsEmbryonic Stem CellsTranscription, GeneticBlotting, WesternAnimals, SucklingMorphogenesisSex DifferentiationGene Expression ProfilingBasic Helix-Loop-Helix Transcription FactorsNeurogenesisRepressor ProteinsGestational AgePromoter Regions, GeneticAmino Acid SequenceModels, BiologicalMutationOrgan SpecificityApoptosisInfant, NewbornTissue DistributionEpigenesis, GeneticNuclear ProteinsDown-RegulationTrans-ActivatorsMicroscopy, ElectronOrgan Culture TechniquesRetinaHL-60 CellsEpithelial CellsGrowthDNA PrimersCell CycleMice, Neurologic MutantsOrgan SizeCritical Period (Psychology)Body WeightTumor Cells, CulturedMice, Mutant StrainsNeurogliaFluorescent Antibody TechniqueUp-RegulationBlotting, NorthernSertoli CellsOsteogenesis