motor neuron
neuron making synapse on an effector (muscle, gland).
RMFL
Ring motor neuron/interneuron
RMHR
Ring motor neuron/interneuron
RMFR
Ring motor neuron/interneuron
RMHL
Ring motor neuron/interneuron
DA1
Ventral cord motor neurons, innervate dorsal muscles
DB3
Ventral cord motor neurons, innervate dorsal muscles
DB5
Ventral cord motor neurons, innervate dorsal muscles
DA4
Ventral cord motor neurons, innervate dorsal muscles
DA6
Ventral cord motor neurons, innervate dorsal muscles
DA9
Ventral cord motor neurons, innervate dorsal muscles
DA2
Ventral cord motor neurons, innervate dorsal muscles
DA3
Ventral cord motor neurons, innervate dorsal muscles
DA8
Ventral cord motor neurons, innervate dorsal muscles
DB4
Ventral cord motor neurons, innervate dorsal muscles
DA7
Ventral cord motor neurons, innervate dorsal muscles
DB2
Ventral cord motor neurons, innervate dorsal muscles
DA5
Ventral cord motor neurons, innervate dorsal muscles
DB1
Ventral cord motor neurons, innervate dorsal muscles
DB6
Ventral cord motor neurons, innervate dorsal muscles
DB7
Ventral cord motor neurons, innervate dorsal muscles
M2 neuron
Neuron class of two pharyngeal motor neurons.
NSM
Neuron class of two pharyngeal neurosecretory-motor neurons.
RMDDL
Ring motor neuron/interneuron, many synapses
RMDL
Ring motor neuron/interneuron, many synapses
CP5
Male specific motor neuron in ventral cord
RMDDR
Ring motor neuron/interneuron, many synapses
CP6
Male specific motor neuron in ventral cord
RMDR
Ring motor neuron/interneuron, many synapses
CP4
Male specific motor neuron in ventral cord
RMDVL
Ring motor neuron/interneuron, many synapses
CP7
Male specific motor neuron in ventral cord
RMDVR
Ring motor neuron/interneuron, many synapses
MI neuron
Neuron class of one pharyngeal motor neuron/interneuron.
VA5
Ventral cord motor neuron, innervates ventral body muscles
PVNR
Interneuron/motor neuron, posterior ventral cord, few synapses
VA3
Ventral cord motor neuron, innervates ventral body muscles
VA8
Ventral cord motor neuron, innervates ventral body muscles
VB9
Ventral cord motor neuron, innervates ventral body muscles
VA2
Ventral cord motor neuron, innervates ventral body muscles
VA4
Ventral cord motor neuron, innervates ventral body muscles
VB10
Ventral cord motor neuron, innervates ventral body muscles
VB2
Ventral cord motor neuron, innervates ventral body muscles
VB8
Ventral cord motor neuron, innervates ventral body muscles
DD3
Ventral cord motor neurons, reciprocal inhibitors, chnage synaptic pattern during postembryonic development
VA1
Ventral cord motor neuron, innervates ventral body muscles
VA10
Ventral cord motor neuron, innervates ventral body muscles
VA6
Ventral cord motor neuron, innervates ventral body muscles
VB5
Ventral cord motor neuron, innervates ventral body muscles
DD2
Ventral cord motor neurons, reciprocal inhibitors, chnage synaptic pattern during postembryonic development
DD6
Ventral cord motor neurons, reciprocal inhibitors, chnage synaptic pattern during postembryonic development
DD4
Ventral cord motor neurons, reciprocal inhibitors, chnage synaptic pattern during postembryonic development
PVNL
Interneuron/motor neuron, posterior ventral cord, few synapses
VA11
Ventral cord motor neuron, innervates ventral body muscles
VA7
Ventral cord motor neuron, innervates ventral body muscles
VA9
Ventral cord motor neuron, innervates ventral body muscles
VB11
Ventral cord motor neuron, innervates ventral body muscles
VB3
Ventral cord motor neuron, innervates ventral body muscles
VB4
Ventral cord motor neuron, innervates ventral body muscles
VB6
Ventral cord motor neuron, innervates ventral body muscles
VB7
Ventral cord motor neuron, innervates ventral body muscles
DD1
Ventral cord motor neurons, reciprocal inhibitors, chnage synaptic pattern during postembryonic development
DD5
Ventral cord motor neurons, reciprocal inhibitors, chnage synaptic pattern during postembryonic development
HSNL
Herm. specific motor neurons (die in male embryo), innervate vulval muscles, serotonergic
HSNR
Herm. specific motor neurons (die in male embryo), innervate vulval muscles, serotonergic
PVN
Neuron class of two interneuron/motor neurons, posterior ventral cord, few synapses.
AVBR
Ventral cord interneuron, synapses onto VB and DB motor neurons; formerly called beta.
AVBL
Ventral cord interneuron, synapses onto VB and DB motor neurons; formerly called beta.
AS10
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS1
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS11
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS6
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS7
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS8
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS9
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
PVV
Neuron class of one male-specific motor neuron, ventral cord.
AS2
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS3
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
AS5
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
SPCR
Male specific sensory /motor neuron, innervates spicule protractor muscle
AS4
Ventral cord motor neuron, innervates dorsal muscles, no ventral counterpart
SPCL
Male specific sensory /motor neuron, innervates spicule protractor muscle
AVAR
Ventral cord interneuron, synapses onto VA, DA, and AS motor neurons; formerly called alpha
AVAL
Ventral cord interneuron, synapses onto VA, DA, and AS motor neurons; formerly called alpha
DA neuron
Neuron class of nine ventral cord motor neuron, innervates dorsal muscle.
PVZ
Neuron class of one male-specific motor neuron, cell body in ventral cord.
SMBDR
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
SMDDR
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
VD13
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD2
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD9
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VB1
Ventral cord motor neuron, innervates ventral body muscles, also interneuron in ring
VD4
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD7
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD8
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
SMBVL
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
SMBVR
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
SMDVL
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
SMDVR
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
VD12
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD3
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
SMBDL
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
VD1
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD10
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD5
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VD6
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
SMDDL
Ring motor neuron/interneuron, has a posteriorly direct ed process that runs sublaterally
VD11
Ventral cord motor neuron, innervates ventral body muscles, probably reciprocal inhibitor
VC3
Hermaphrodite specific ventral cord motor neuron innervates vulval muscles and ventral body muscles
VC4
Hermaphrodite specific ventral cord motor neuron innervates vulval muscles and ventral body muscles
VC1
Hermaphrodite specific ventral cord motor neuron innervates vulval muscles and ventral body muscles
VC2
Hermaphrodite specific ventral cord motor neuron innervates vulval muscles and ventral body muscles
VC5
Hermaphrodite specific ventral cord motor neuron innervates vulval muscles and ventral body muscles
VC6
Hermaphrodite specific ventral cord motor neuron innervates vulval muscles and ventral body muscles
VA12
Ventral cord motor neuron, innervates ventral body muscles, but also interneuron in preanal ganglion
PVCR
Ventral cord interneuron, cell body in lumbar ganglion, synapses onto VB and DB motor neurons, formerly called delta.
PVCL
Ventral cord interneuron, cell body in lumbar ganglion, synapses onto VB and DB motor neurons, formerly called delta.
PDB
Neuron class of one motor neuron, process in dorsal cord, cell body in pre-anal ganglion.
PDA
Neuron class of one motor neuron, process in dorsal cord, same as Y cell in hermaphrodite, Y.a in male.
command interneuron
a type of interneurons whose synaptic output represent a final common pathway to motor neurons. The synaptic activities of command interneurons lead directly to the control of locomotion.
GLRVL
Set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons
GLRVR
Set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons
GLRR
Set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons
GLRDL
Set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons
GLRDR
Set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons
GLRL
Set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons
GLR
set of six cells that form a thin cylindrical sheet between pharynx and ring neuropile; no chemical synapses, but gap junctions with muscle arms and RME motor neurons, might be glial cells
ventral cord blast cell
Blast cell lying ventrolaterally in the late embryo and L1 larval stage which divides during the late L1 larva in stereotypical reiterated fashion to give rise to many motor neurons which begin function in the ventral cord and preanal ganglion of the early L2 larva, as well as hypodermal cells (which fuse into
hyp7) and a series of programmed cell deaths. In addition, the Pn.p daughters of P3 through P8 lineages persist without fusing into the
hyp7 syncytium until mid L3 stage when they can be induced to divide further to produce vulval epithelial cells (vulA - vulF) or more
hyp7 cells. P0 is also known as W.
CEPDL
Cephalic neurons, contain dopamine
CEPVR
Cephalic neurons, contain dopamine
OLLR
Lateral outer labial neurons
CEPDR
Cephalic neurons, contain dopamine
CEPVL
Cephalic neurons, contain dopamine
PHAL
Phasmid neurons, probably chemosensory
PHBL
Phasmid neurons, probably chemosensory
OLLL
Lateral outer labial neurons
PHAR
Phasmid neurons, probably chemosensory
MCR
Pharyngeal neurons that synapse onto marginal cells
MCL
Pharyngeal neurons that synapse onto marginal cells
IL2 neuron
Neuron class of six ciliated neurons, each of which is one of the two component neurons of the six inner labial sensilla.
IL1 neuron
Neuron class of six ciliated neurons with striated rootlets, each of which is one of two component neurons of the inner labial sensilla.
PHA
Neuron class of two phasmid neurons, type A.
PHB
Neuron class of two phasmid neurons, type B.
CEP
Neuron class of four neurons associated with cephalic sensilla.
sensillum
sensory organ, consists of sensory neurons and supporting cells.
CA neuron
Neuron class of nine male-specific neurons, innervate dorsal muscles.
SPV
Neuron class of two male-specific neurons that innervate male spicule.
ALM
Neuron class of two anterior sensory neurons that transduce touch stimuli.
CEM
Neuron class of four male-specific neurons associated with cephalic sensilla.
PLM
Neuron class of two posterior sensory neurons that transduce touch stimuli.
AUA
Neuron class of two neurons with cell bodies situated in the lateral ganglia.
PDE
Neuron class of two neurons with ciliated endings in the posterior deirid sensilla.
PLN
Neuron class of two neurons with cell bodies situated in the lumbar ganglion.
CAN
Neuron class of two neurons that are closely associated with the excretory canal.
PVP
Neuron class of two neurons with cell bodies situated in the pre-anal ganglion.
R5B
Neuron class of two male-specific sensory ray neurons type B of ray five.
R9B
Neuron class of two male-specific sensory ray neurons type B of ray nine.
V cell
Ventrolateral ectoblast of the body that gives rise to neurons, hypodermis and seam cells.
R3A
Neuron class of two male-specific sensory ray neurons type A of ray three.
R3B
Neuron class of two male-specific sensory ray neurons type B of ray three.
R6A
Neuron class of two male-specific sensory ray neurons type A of ray six.
R6B
Neuron class of two male-specific sensory ray neurons type B of ray six.
R8A
Neuron class of two male-specific sensory ray neurons type A of ray eight.
R1A
Neuron class of two male-specific sensory ray neurons type A of ray one.
OLL
Neuron class of two neurons with ciliated endings in the lateral outer labial sensilla.
R1B
Neuron class of two male-specific sensory ray neurons type B of ray one.
R2A
Neuron class of two male-specific sensory ray neurons type A of ray two.
R4B
Neuron class of two male-specific sensory ray neurons type B of ray four.
R7B
Neuron class of two male-specific sensory ray neurons type B of ray seven.
R2B
Neuron class of two male-specific sensory ray neurons type B of ray two.
R4A
Neuron class of two male-specific sensory ray neurons type A of ray four.
R8B
Neuron class of two male-specific sensory ray neurons type B of ray eight.
AWAL
Amphid wing cells, neurons having ciliated sheet-like sensory endings closely associated with amphid sheath
AWBL
Amphid wing cells, neurons having ciliated sheet-like sensory endings closely associated with amphid sheath
AWCL
Amphid wing cells, neurons having ciliated sheet-like sensory endings closely associated with amphid sheath
AWAR
Amphid wing cells, neurons having ciliated sheet-like sensory endings closely associated with amphid sheath
AWBR
Amphid wing cells, neurons having ciliated sheet-like sensory endings closely associated with amphid sheath
AWCR
Amphid wing cells, neurons having ciliated sheet-like sensory endings closely associated with amphid sheath
AWC-OFF
one of the two AWC neurons, stochastically determined, in which the
str-2 promoter is inactive
EF1
Male specific neuron, large cell body in preanal ganglion, synaptic inputs from ray neurons, class one.
pharyngeal nervous system
The pharyngeal nervous system is composed of 20 pharyngeal neurons which lie completely within the pharynx.
ADE
Neuron class of two sensory neurons of anterior deirids, sensory receptors in lateral alae, contain dopamine.
CP neuron
Neuron class of nine male-specific neurons with cell body in ventral cord and preanal ganglion
EF3
Male specific neuron, large cell body in preanal ganglion, synaptic inputs from ray neurons, class three.
AWC-ON
one of the two AWC neurons, stochastically determined, in which the
str-2 promoter is active
EF2
Male specific neuron, large cell body in preanal ganglion, synaptic inputs from ray neurons, class two.
EF4
Male specific neuron, large cell body in preanal ganglion, synaptic inputs from ray neurons, class four.
AWA
Neuron class of two ciliated neurons that are associated with the sheath cells of the amphid sensilla.
PHDR
The right PHD neuron of the pair of bilateral PHD neurons in a male C. elegans animal.
PHDL
The left PHD neuron of the pair of bilateral PHD neurons in a male C. elegans animal.
R9A
Neuron class of two male-specific neurons that are associated with ninth male sensory ray, A neuron type.
R5A
Neuron class of two male-specific neurons that are associated with fifth male sensory ray, A neuron type.
R7A
Neuron class of two male-specific neurons that are associated with seventh male sensory ray, A neuron type.
OLQ
Neuron class of four neurons with ciliated endings and striated rootlets in the dorsal and ventral outer labial sensilla.
CEMDL
Male specific cephalic neurons (programmed cell death in hermaphrodite embryo) open to outside, possible function in male chemotaxis toward hermaphrodite.
CEMDR
Male specific cephalic neurons (programmed cell death in hermaphrodite embryo) open to outside, possible function in male chemotaxis toward hermaphrodite.
CEMVL
Male specific cephalic neurons (programmed cell death in hermaphrodite embryo) open to outside, possible function in male chemotaxis toward hermaphrodite.
CEMVR
Male specific cephalic neurons (programmed cell death in hermaphrodite embryo) open to outside, possible function in male chemotaxis toward hermaphrodite.
EF neuron
Neuron class of four large, male-specific interneurons with cell bodies in preanal ganglion. They receive synaptic inputs from ray neurons.
head muscle
body wall muscle in the head, including first eight cells of each muscle quadrants which are innervated by nerve ring neurons.
body wall
exterior tube of two concentric tubes that make up the body, includes the epidermal cells and the attached neurons and muscles.
AWB
Neuron class of two ciliated neurons with flattened, sheet-like endings that are associated with the sheath cells of the amphid sensilla
AWC
Neuron class of two ciliated neurons with large, flattened, sheet-like endings that are associated with the sheath cells of the amphid sensilla.
URX
Neuron class of two neurons with cell bodies that are situated sub-dorsally in the pseudocoelomic cavity just posterior to the ring neuropile.
ASG
Neuron class of two ciliated neurons that are part of the amphid sensilla; the endings are in the amphid channel, which is open to the outside.
ASHR
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASJ
Neuron class of two ciliated neurons that are part of the amphid sensilla. The endings are in the amphid channel, which is open to the outside.
ASKL
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
BAG
Neuron class of two neurons with ciliated endings, in the head, with elliptical, closed, sheet-like processes near the cilium, which envelop a piece of hypodermis.
ASGL
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASHL
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASKR
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASGR
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASI
Neuron class of two ciliated neurons that are part of the amphid sensilla; the endings are in the amphid channel, which is open to the outside.
ASIL
one member of amphid neurons, single ciliated ending, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASIR
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASEL
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASH
Neuron class of two ciliated neurons that are part of the amphid sensilla; the endings are in the amphid channel, which is open to the outside.
ASJL
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASJR
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASE
Neuron class of two ciliated neurons that are part of the amphid sensilla; the endings are in the amphid channel, which is open to the outside
ASER
one member of Amphid neurons, single ciliated endings, probably chemo-sensory; project into ring via commissure from ventral ganglion, make diverse synaptic connections in ring neuropil
ASK
Neuron class of two ciliated neurons that are part of the amphid sensilla. The endings are in the amphid channel, which is open to the outside.
URY
Neuron class of four neurons with cell bodies situated anterior to the nerve ring. presynaptic in ring, non-ciliated endings in head, associated with OLQ in embryo
ADL
Neuron class of two neurons that have dual ciliated endings in the amphid sensillum; the endings are in the amphid channel, which is open to the outside.
AFD
Neuron class of two ciliated neurons that are part of the amphid sensillum; the endings of AFD have numerous villi, which poke into the amphid sheath cells.
lumbar ganglion
The left and right lumbar ganglia lie behind the pre-anal ganglion in the tail, in lateral positions. Each contains 12 neuron cell bodies that send most of their neuronal processes into the ventral nerve cord via lumbar commissures and the pre-anal ganglion. There is no local neuropil in these ganglia in the hermaphrodite, instead they form most synapses in the pre-anal ganglion. Most lumbar neurons have sensory functions. In the adult male tail, these two ganglia gain many additional neurons and have some local neuropil. The lumbar neurons lie in close association with the lateral hypodermis, and most are posterior to the anus.
egg-laying apparatus
An apparatus for laying eggs of the hermaphrodite reproductive system, consists of the uterus, the uterine muscles, the vulva, the vulval muscles, and a local neuropil formed by the egg-laying neurons.
ALN
Neuron class of two neurons with cell bodies situated in the lumbar ganglion, send processes anteriorly, which eventually enter the nerve ring; they also have posteriorly directed processes that run into the tailspike.
PHD
A neuron belonging to a class of 2 bilateral, cholinergic, peptidergic, male-specific, ciliated neurons generated by transdifferentiation from a male PHso1 glial cell in the late L4 larval stage of a male C. elegans animal.
FLP
Neuron class of two neurons, which have ciliated endings situated immediately dorsal to the lateral inner labial sensilla in the head but have no associated sheath or socket cells; they have flattened processes in this region of the cilium.
tail precursor cell
Tail lateral ectoblasts that give rise to neurons, hypodermis and glial lineages. While initially identical, after the L2 lethargus the T cell lineages become markedly different between males and hermaphrodites helping to provide the sexually dimorphic tail structures found in males.
PHC
Neuron class of two neurons with cell bodies situated in the lumbar ganglia. Posteriorly directed processes run from the cell bodies into the tails pike running alongside the processes of PLM and PLN. The disposition of these processes suggests that they may be sensory dendrites.
neuronal sheath cell
a structural (glial) cell which forms an specialized environment surrounding the sensory ending(s) of one or more neurons; sometimes accompanied by a more distal socket cell. In early development of the sensory nerves and of the nerve ring some sheath cells (cephalics and labials) may also provide a substrate for axon guidance
dorso-rectal ganglion
the ganglion that lies above and behind the rectum in the tail, in close continuity with the anal hypodermal ridge. It contains 3 neuron cell bodies (DVA, DVB and DVC) that send their neuronal processes into the ventral nerve cord via dorso-rectal commissures that encircle the anus. The ganglion contains no local neuropil in the hermaphrodite. In the adult male tail, this ganglion gains additional neurons and some local neuropil.
accessory cell
cells that support sensory neurons, similar to glial cells in vertebrates. A category which collectively refers to socket cells, sheath cells, and structural cells, or their processes. All of these cells extend long processes which serve a supporting role, rather like glia, to form a protective environment around sensory neuron endings. In addition, some of these cells extend broad thin processes from their somata which wrap around neuronal ganglia, again in a glia-like fashion
ADF
Neuron class of two neurons that have dual ciliated endings in the amphid sensillum. The endings are in the amphid channel, which is open to the outside. Processes from lateral cell bodies enter the ventral cord via the amphidial commissures and turn anteriorly to enter the nerve ring. The processes of ADF run near the outside surface and posterior face of the ring, in close association with those of AIZ. They meet at the dorsal mid-line and terminate; there is a gap junction at the point or contact. The main synaptic output is to RIA and AIZ; there are also synapses to SMB, AUA and RIR, usually in dyadic combinations with RIA or AIZ. AWB synapses onto ADF in several places, and there are gap junctions to RIH, ADA and AIA.