Nematode worm

The first animal whose entire nervous system was mapped. 302 neurons, wired almost identically in every individual, controlling crawling, feeding, egg laying and escape.

Real connectomeCook et al. 2019 hermaphrodite connectome with Wang et al. 2024 transmitter atlas

Stimulate and silence cells See it in an experiment

302

neurons

136

cell types

3,709

chemical pairs

2,196

gap junction pairs

32,488

synapses

Who talks to whom

Synapses between neuron classes. Cells show the share of the sending class's output.

Neuron classes

How the system divides its neurons.

sensory85

interneuron89

motor126

other2

Transmitters

Green excites, blue inhibits, grey is modulatory or unknown in this model.

ACH160

GLUT78

unknown31

GABA29

BET4

Cell types

Sorted by total synapses. Use these names in the lab.

Cell type	Class	Transmitter	Neurons	Synapses in	Synapses out
ALA	interneuron	GABA	1	1,326	1,546
AVA	interneuron	ACH	2	1,829	1,027
CAN	other	?	2	1,062	1,002
VD	motor	GABA	13	1,545	513
PVD	sensory	GLUT	2	905	967
RIA	interneuron	GLUT	2	863	865
PVC	interneuron	ACH	2	926	710
VA	motor	ACH	12	651	820
DA	motor	ACH	9	688	665
AVB	interneuron	ACH	2	932	380
VB	motor	ACH	11	376	793
DD	motor	GABA	6	988	163
AVE	interneuron	ACH	2	690	348
PVP	interneuron	ACH	2	478	544
AVD	interneuron	ACH	2	609	402
AIZ	interneuron	GLUT	2	486	499
AIB	interneuron	GLUT	2	607	362
RIM	interneuron	GLUT	2	548	418
DB	motor	ACH	7	290	645
RIG	interneuron	GLUT	2	428	425
RIB	interneuron	GABA	2	556	255
RMDV	motor	ACH	2	605	180
AS	motor	ACH	11	410	370
RMDD	motor	ACH	2	630	101
SMDD	motor	ACH	2	496	202
SMDV	motor	ACH	2	336	352
AIY	interneuron	ACH	2	272	414
AIA	interneuron	ACH	2	430	236
FLP	sensory	GLUT	2	101	476
RMD	motor	ACH	2	393	180
AVJ	interneuron	GABA	2	312	226
AVH	interneuron	?	2	251	282
AVK	interneuron	?	2	313	220
PVQ	interneuron	?	2	263	261
OLL	sensory	GLUT	2	139	365
ADF	sensory	ACH	2	127	375
PVR	interneuron	GLUT	1	198	303
RIP	interneuron	ACH	2	443	58
VC	motor	ACH	6	160	335
ASH	sensory	GLUT	2	135	356
PHB	sensory	GLUT	2	100	386
DVA	sensory	ACH	1	234	246
SAAV	interneuron	ACH	2	165	303
DVC	interneuron	GLUT	1	183	252
RIC	interneuron	GLUT	2	213	215
AVF	interneuron	?	2	201	221
ADL	sensory	GLUT	2	91	323
CEPD	sensory	?	2	79	332
PDE	sensory	GLUT	2	232	175
URX	sensory	ACH	2	166	241
SMBD	motor	ACH	2	216	188
ASE	sensory	GLUT	2	135	264
ASK	sensory	GLUT	2	185	211
RMG	interneuron	?	2	148	242
RIH	interneuron	ACH	1	116	272
CEPV	sensory	?	2	113	271
PVN	interneuron	ACH	2	145	237
SMBV	motor	ACH	2	213	163
LUA	interneuron	GLUT	2	115	249
PVT	interneuron	?	1	176	186
IL1V	sensory	GLUT	2	170	190
ADE	sensory	?	2	111	243
AQR	sensory	GLUT	1	149	201
OLQV	sensory	GLUT	2	187	162
ADA	interneuron	GLUT	2	120	223
RIV	motor	ACH	2	159	176
AWC	sensory	GLUT	2	131	190
AVL	interneuron	GABA	1	166	154
AUA	interneuron	GLUT	2	123	191
URYV	sensory	GLUT	2	36	272
SAAD	interneuron	ACH	2	153	153
RIS	interneuron	GABA	1	77	221
HSN	motor	ACH	2	105	184
IL1D	sensory	GLUT	2	142	146
IL1	sensory	GLUT	2	99	183
NSM	sensory	BET	2	191	91
IL2V	sensory	ACH	2	23	258
IL2	sensory	ACH	2	55	218
PLM	sensory	GLUT	2	70	202
BAG	sensory	GLUT	2	99	171
SDQ	sensory	ACH	2	82	186
URB	interneuron	ACH	2	93	171
OLQD	sensory	GLUT	2	152	109
PHA	sensory	GLUT	2	86	168
SIBV	motor	ACH	2	185	68
SIAD	motor	ACH	2	130	117
PQR	sensory	GLUT	1	81	164
ASG	sensory	GLUT	2	70	169
AFD	sensory	ACH	2	119	116
RIF	interneuron	ACH	2	82	150
SIAV	motor	ACH	2	177	55
AWA	sensory	ACH	2	57	165
RMH	motor	ACH	2	167	55
IL2D	sensory	ACH	2	12	205
I2	interneuron	GLUT	2	55	159
AWB	sensory	ACH	2	70	137
PHC	sensory	GLUT	2	42	164
RME	motor	GABA	2	171	29
ALM	sensory	GLUT	2	67	129
RIR	interneuron	ACH	1	79	112
URYD	sensory	GLUT	2	47	142
SIBD	motor	ACH	2	129	56
URAV	motor	ACH	2	73	112
DVB	interneuron	GABA	1	62	121
RMF	interneuron	ACH	2	100	82
AIM	interneuron	GLUT	2	46	134
AVG	interneuron	ACH	1	84	95
PVW	interneuron	?	2	91	78
AVM	sensory	GLUT	1	40	126
ASJ	sensory	ACH	2	49	111
BDU	interneuron	?	2	65	95
AIN	interneuron	ACH	2	35	118
RMEV	motor	GABA	1	114	33
M3	motor	GLUT	2	134	9
SABV	motor	ACH	2	115	28
ALN	sensory	ACH	2	63	72
I4	interneuron	GLUT	1	64	70
ASI	sensory	BET	2	41	88
RID	interneuron	?	1	81	46
PLN	sensory	ACH	2	56	70
I1	interneuron	ACH	2	30	90
M4	motor	ACH	1	84	34
PVM	sensory	?	1	40	76
I6	interneuron	?	1	17	95
URAD	motor	ACH	2	56	51
RMED	motor	GABA	1	80	26
SABD	motor	ACH	1	71	32
M2	motor	ACH	2	52	50
PDB	motor	ACH	1	37	49
I5	interneuron	GLUT	1	24	61
PDA	motor	ACH	1	24	52
I3	interneuron	ACH	1	33	25
MC	motor	?	2	37	18
MI	motor	GLUT	1	21	32
M1	motor	ACH	1	20	30
M5	motor	ACH	1	7	6

Hub neurons

The most connected individual cells.

Neuron	Type	Synapses
ALA	ALA	2,872
AVAR	AVA	1,477
AVAL	AVA	1,379
CANL	CAN	1,032
CANR	CAN	1,032
PVDR	PVD	942
PVDL	PVD	930
RIAR	RIA	878
PVCR	PVC	866
RIAL	RIA	850
PVCL	PVC	770
AVBL	AVB	667
AVBR	AVB	645
PVPR	PVP	533
AVER	AVE	532

Read before you conclude

What this dataset and model can and cannot tell you.

Most C. elegans neurons are graded, not spiking. The lab uses the same spiking model as for flies, a strong simplification. Some reflexes (nose touch) are reproduced, others (tail touch) are not.
Glutamate can excite or inhibit depending on the receptor. It is treated as excitatory here because the classic touch and escape reflexes (ASH, FLP, PLM onto command interneurons) use excitatory glutamate receptors. Some synapses, such as AWC onto AIY, are actually inhibitory.
Gap junctions are modelled as simple electrical coupling with one shared strength.

Cite

Data redistributed by OpenWorm ConnectomeToolbox (MIT). Cite the original papers.

Cook, S. J. et al. (2019). Whole-animal connectomes of both Caenorhabditis elegans sexes. Nature 571, 63-71.
Wang, C. et al. (2024). A neurotransmitter atlas of C. elegans males and hermaphrodites. eLife 13, RP95402.
Gleeson, P. et al. ConnectomeToolbox, OpenWorm. https://github.com/openworm/ConnectomeToolbox