Skip to content

Varshney et al. 2011

Structural Properties of the Caenorhabditis elegans Neuronal Network

Lav R. Varshney, Beth L. Chen, Eric Paniagua, David H. Hall, Dmitri B. Chklovskii
PLOS Computational Biology 7(2): e1001066
Published: February 3, 2011

Datasets incorporated

Resources from publication

Data Acquisition

  • Assembled wiring diagram by consolidating existing data from both published and unpublished sources

White et al. 1986 The Mind of a Worm (MOW) was the starting point

  • Extracted wiring data from diagrams, figures, tables and text
  • Connectivity of each neuron, its synaptic partners, and synaptic type was manually entered into an electronic database
  • In the ventral cord, determining this level of synaptic specification was complicated by the fact that connections were recorded by neuron class
  • Assigned proper connections to the appropriate left/right neuron by referring to White and co-worker's original laboratory notebooks and original EMs

Durbin 1987 - the anterior portion of the worm

  • Anterior connections needed an update as MOW did not specify the location of synapses, integration proved difficult.
  • For these neurons, they obtained positional information by cross-referencing Durbin's data against original EMs and his handwritten annotations in White's laboratory notebooks.
  • Only synapses located in regions addressed by Durbin were included.
  • Connections in the middle and tail region of the worm were mostly unaffected by these updates.

Differences in data and gaps

  • Hobert O and Hall DH, unpublished - differences between GFP neurons and White's work have been observed
    • anterior processes of DVB and PVT could have been mistakenly switched in MOW
    • so they reversed the connections for neurons DVB and PVT anterior to the vulva
  • Reconstructions of neurons in the mid-body of the worm are incomplete
  • From a combination of these published works
    • White et al 1986
    • Durbin RM 1987
    • Hall DH, Russel RL 1991
    • White et al 1976
  • Wiring data for 64 neurons had large gaps or were missing entirely
    • 61 of these were motor neurons in the ventral cord
  • 2 were excretory neurons (CANL/R) that do not appear to make any synapses
    • RID is the only process in the dorsal cord that extends over the length of the animal

Updates to previous data

  • Using White et al. laboratory notebooks, they identified notes for full reconstructions of 24 of the aforementioned neurons
  • Partial connectivity data for the remaining 38 were also available where 22 neurons have partial/missing dorsal side connections and 6 neurons have partial ventral side connections
  • 600 updates were made to the original notes and published reconstructions
    • additions of previously missed NMJs between ventral cord motor neurons and body wall muscles
  • Large section on the dorsal side of the worm was never EM at high power magnification
    • produced new high power EMs of this dorsal region
    • 3 neurons (DA5, DB4, DD3) were obtained from these EMs
    • resource constraints prevented them from covering the entire dorsal gap
  • reconciliation of discrepancies
    • 561 synapses for 108 neurons (49% chemical "sends", 31% chemical "receives" and 20% for electrical junctions)