Cerebral Cortex/cytology; Gene Expression Regulation, Developmental/physiology; Hedgehog Proteins/metabolism; Nerve Net/metabolism; Neurons/metabolism; Pyramidal Tracts/physiology; Age Factors; Animals; Animals, Newborn; Cerebral Cortex/growth & development; Channelrhodopsins; Corpus Callosum/cytology; Corpus Callosum/growth & development; DNA-Binding Proteins/metabolism; Dendritic Spines/metabolism; Dendritic Spines/physiology; Electric Stimulation; Electroporation/methods; Fluorobenzenes/metabolism; Functional Laterality/genetics; Furans/metabolism; Gene Expression Regulation, Developmental/genetics; Hedgehog Proteins/genetics; Immunoglobulin G/genetics; Immunoglobulin G/metabolism; In Vitro Techniques; Luminescent Proteins/genetics; Luminescent Proteins/metabolism; Matrix Attachment Region Binding Proteins/metabolism; Membrane Potentials/genetics; Mice; Mice, Transgenic; Mutation/genetics; Nerve Net/cytology; Neurons/ultrastructure; Nuclear Proteins/metabolism; Patch-Clamp Techniques; Phosphopyruvate Hydratase/metabolism; RNA, Small Interfering/genetics; RNA, Small Interfering/metabolism; Receptors, Cell Surface/genetics; Receptors, Cell Surface/metabolism; Repressor Proteins/metabolism; Silver Staining/methods; Stilbamidines/metabolism; Synapses/metabolism; Synapses/ultrastructure; Synaptophysin/genetics; Synaptophysin/metabolism; Transcription Factors/metabolism; Tumor Suppressor Proteins/metabolism; Ubiquitin-Protein Ligases; gamma-Aminobutyric Acid/metabolism