title: Laminar and columnar development of barrel cortex relies on thalamocortical neurotransmission.
abstract: A dynamic interplay between intrinsic regional molecular cues and extrinsic factors from the thalamus shape multiple features of early cortical development. It remains uncertain and controversial, however, whether the initial formation of cortical columns depends on neuronal activity, and there is little evidence that cortical lamination or neuronal differentiation is influenced by extrinsic activity. We examined the role of thalamic-derived factors in cortical development by selectively eliminating glutamatergic synaptic transmission from thalamocortical neurons in mice and found that eliminating thalamocortical neurotransmission prevented the formation of "barrel" columns in somatosensory cortex. Interestingly, based on cytoarchitectonic criteria and genetic markers, blocking thalamocortical neurotransmission also perturbed the development of superficial cortical lamina and the morphologic development of neurons. These experiments demonstrate that barrels and aspects of the layer-dependent pattern of cortical cytoarchitecture, gene expression, and neuronal differentiation depend on thalamocortical neurotransmission, extending the apparent influence of extrinsic, presumably activity-dependent factors, on cortical development.
authors.affiliation: Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Sofia
authors.initials: S
authors.lastname: Fertuzinhos
authors.forename: Ethan
authors.initials: E
authors.lastname: Mohns
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hnasko
authors.forename: Matthijs
authors.initials: M
authors.lastname: Verhage
authors.forename: Robert
authors.initials: R
authors.lastname: Edwards
authors.forename: Nenad
authors.initials: N
authors.lastname: Sestan
authors.forename: Michael C
authors.initials: MC
authors.lastname: Crair
mesh_terms: D000818:Animals; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D018698:Glutamic Acid / Q000502:physiology*; D051379:Mice; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D013003:Somatosensory Cortex / Q000254:growth & development* / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D013788:Thalamus / Q000166:cytology* / Q000502:physiology
chemical_list: D018698:Glutamic Acid