title: Inhibitory dendrite dynamics as a general feature of the adult cortical microcircuit.
abstract: The mammalian neocortex is functionally subdivided into architectonically distinct regions that process various types of information based on their source of afferent input. Yet, the modularity of neocortical organization in terms of cell type and intrinsic circuitry allows afferent drive to continuously reassign cortical map space. New aspects of cortical map plasticity include dynamic turnover of dendritic spines on pyramidal neurons and remodeling of interneuron dendritic arbors. While spine remodeling occurs in multiple cortical regions, it is not yet known whether interneuron dendrite remodeling is common across primary sensory and higher-level cortices. It is also unknown whether, like pyramidal dendrites, inhibitory dendrites respect functional domain boundaries. Given the importance of the inhibitory circuitry to adult cortical plasticity and the reorganization of cortical maps, we sought to address these questions by using two-photon microscopy to monitor interneuron dendritic arbors of thy1-GFP-S transgenic mice expressing GFP in neurons sparsely distributed across the superficial layers of the neocortex. We find that interneuron dendritic branch tip remodeling is a general feature of the adult cortical microcircuit, and that remodeling rates are similar across primary sensory regions of different modalities, but may differ in magnitude between primary sensory versus higher cortical areas. We also show that branch tip remodeling occurs in bursts and respects functional domain boundaries.
authors: Picower Institute for Learning and Memory and Departments of Biology and Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors: Jerry L
authors: JL
authors: Chen
authors: Genevieve H
authors: GH
authors: Flanders
authors: Wei-Chung Allen
authors: WC
authors: Lee
authors: Walter C
authors: WC
authors: Lin
authors: Elly
authors: E
authors: Nedivi
mesh_terms: D000818:Animals; D001931:Brain Mapping; D003712:Dendrites / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D007395:Interneurons / Q000166:cytology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D017711:Nonlinear Dynamics; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000166:cytology*; D014795:Visual Pathways / Q000502:physiology
chemical_list: D049452:Green Fluorescent Proteins