Worm Breeder's Gazette 1(1): 20a

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Title unknown.

Authors unknown.

Two young adult animals have been serially sectioned from the tip of 
the tail forward through the anterior end of the preanal ganglion.  
The 9 cells of each lumbar ganglion and the 12 cells of the preanal 
ganglion can be reproducibly identified on the basis of a set of 
morphological features, including cell body position, direction and 
extent of fiber projection, fiber size, and cytoplasmic appearance.  A 
total of at least 6 bilaterally homologous pairs can be identified 
among the lumbar cells.  Virtually all the synaptic contacts occur in 
the preanal ganglion; very few are found in the lumbar ganglia.  
However, the most prominent participants in these synapses are lumbar 
cells and a few cells whose bodies lie anterior to the sectioned 
region; the preanal ganglion cells themselves are relatively minor 
A complete connectivity matrix has been constructed for both animals,
involving about 90 synapses in each case.  Certain cells make 
repeated contacts with one another (up to 13 contacts) in both animals.
Other instances of non-reproducible synapses are found, usually 
involving one contact in one animal and none in the other.  
Homologously paired cells make similar sets of synaptic contacts.  
Most (~85/90) of the contacts are diadic, with one presynaptic cell 
and two postsynaptic ones.  Several instances of 'multiple routes of 
information flow' are found, in which cell A sends to cell C in two 
ways, both by direct synaptic contact and through an intervening cell, 
B.  No self-synapses are observed, but sensory cells frequently 
synapse onto their bilateral homologs.  One case of reciprocal synapse 
formation is found.  Most of the contacts can be included in a simple 
wiring diagram by which information flows from sensory cells through 
multiple routes to converge on a pair of interneurons that apparently 
constitute one of the major outputs of the system.