title: Conserved properties of dendritic trees in four cortical interneuron subtypes.
abstract: Dendritic trees influence synaptic integration and neuronal excitability, yet appear to develop in rather arbitrary patterns. Using electron microscopy and serial reconstructions, we analyzed the dendritic trees of four morphologically distinct neocortical interneuron subtypes to reveal two underlying organizational principles common to all. First, cross-sectional areas at any given point within a dendrite were proportional to the summed length of all dendritic segments distal to that point. Consistent with this observation, total cross-sectional area was almost perfectly conserved at bifurcation points. Second, dendritic cross-sections became progressively more elliptical at more proximal, larger diameter, dendritic locations. Finally, computer simulations revealed that these conserved morphological features limit distance dependent filtering of somatic EPSPs and facilitate distribution of somatic depolarization into all dendritic compartments. Because these features were shared by all interneurons studied, they may represent common organizational principles underlying the otherwise diverse morphology of dendritic trees.
authors.affiliation: Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki. 444-8787, Japan. yoshiy@nips.ac.jp
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kubota
authors.forename: Fuyuki
authors.initials: F
authors.lastname: Karube
authors.forename: Masaki
authors.initials: M
authors.lastname: Nomura
authors.forename: Allan T
authors.initials: AT
authors.lastname: Gulledge
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mochizuki
authors.forename: Andreas
authors.initials: A
authors.lastname: Schertel
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kawaguchi
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology*; D003712:Dendrites; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008870:Microtubules; D051381:Rats; D017208:Rats, Wistar