title: Mechanisms controlling the guidance of thalamocortical axons through the embryonic forebrain.
abstract: Thalamocortical axons must cross a complex cellular terrain through the developing forebrain, and this terrain has to be understood for us to learn how thalamocortical axons reach their destinations. Selective fasciculation, guidepost cells and various diencephalic and telencephalic gradients have been implicated in thalamocortical guidance. As our understanding of the relevant forebrain patterns has increased, so has our knowledge of the guidance mechanisms. Our aim here is to review recent observations of cellular and molecular mechanisms related to: the growth of thalamofugal projections to the ventral telencephalon, thalamic axon avoidance of the hypothalamus and extension into the telencephalon to form the internal capsule, the crossing of the pallial-subpallial boundary, and the growth towards the cerebral cortex. We shall review current theories for the explanation of the maintenance and alteration of topographic order in the thalamocortical projections to the cortex. It is now increasingly clear that several mechanisms are involved at different stages of thalamocortical development, and each contributes substantially to the eventual outcome. Revealing the molecular and cellular mechanisms can help to link specific genes to details of actual developmental mechanisms.
authors.affiliation: University of Oxford, Department of Physiology, Anatomy and Genetics, Le Gros Clark Building, South Parks Road, Oxford OX1 3QX, UK. zoltan.molnar@dpag.ox.ac.uk
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Molnár
authors.forename: Sonia
authors.initials: S
authors.lastname: Garel
authors.forename: Guillermina
authors.initials: G
authors.lastname: López-Bendito
authors.forename: Patricia
authors.initials: P
authors.lastname: Maness
authors.forename: David J
authors.initials: DJ
authors.lastname: Price
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D019521:Body Patterning / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008954:Models, Biological; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000166:cytology*; D013788:Thalamus / Q000166:cytology / Q000196:embryology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D014157:Transcription Factors