DA1, DA2, DA3, DA4, DA5, DA6, DA7, DA8, DA9
Type: Motor neuron
In MoW: DAn
Male Wiring Project:
DA01,
DA02,
DA03,
DA04,
DA05,
DA06,
DA07,
DA08,
DA09
In Wormbase: DA1, DA2, DA3, DA4, DA5,
DA6, DA7, DA8, DA9
Lineage: AB prppapaap, AB plppapapa
AB prppapapa, AB plppapapp
AB prppapapp, AB plpppaaap
AB prpppaaap, AB prpapappp,
AB plpppaaaa
Location: Body (ventral nerve cord)
Description: Ventral cord "dorsal A" motor neurons. These neurons innervate dorsal muscles. Hermaphrodites and males exhibit some differences in DAn connectivity.
Neurotransmitter/ Neuropeptide:
- Acetylcholine
(Duerr et al., 2008; Rand and Nonet, 1997-Appendix 2)
Innexin expression:
- INX-3
- INX-7
- UNC-9
(Altun et al., 2009)
Receptor expression:
- ACR-14; nicotinic AChR alpha subunit
- UNC-8; mechanically gated ion channel subunit; amiloride-sensitive Na+ channel (ASC) protein (DEG/ENaC subunit)
- SER-2; DA9 expresses a splice variant of this tyramine receptor (Goodman, 2006; Tsalik et al., 2003;Tavernarakis et al., 1997)
Function:
- Backward locomotion. DA neurons receive input from the driver interneuron AVA, and modulator interneurons AVD and AVE. They send output to VD neurons. See Locomotory circuit. |
![](../Images/DA1.jpg)
![](../Images/DA3.jpg)
![](../Images/DA8.jpg)
![](../Images/DA9.jpg)
|
Click pictures for higher resolution images
Male Wiring Project
Note: In males, DA8 and DA9 cell bodies lies posterior to the male-specific CP9 neuron, which defines the anterior boundary of the male pre-anal ganglion (see Male Tail Cell ID). In males, DA8 and DA9 are therefore considered part of the pre-anal ganglion rather than the ventral nerve cord.
For Male Wiring Project details see Emmons lab website.
Schematic Diagrams of
Ventral Cord motor neurons:
AS Neurons
![AS neurons](../../images/VCMNdorsalASlr.jpg) |
DA and DB Neurons
![Dosal DA and DB neurons](../../images/VCMNdorsalABlr.jpg) |
VA Neurons
![VA neurons](../../images/VCMNventralAlr.jpg)
|
VB Neurons
![VB neurons](../../images/VCMNventralBlr.jpg) |
VC Neurons
![VC neurons](../../images/VCMNventralClr.jpg) |
DD and VD Neurons
![DD VD neurons](../../images/VCMNventraldorsalDlr.jpg) |
In all diagrams,axon processes with
neuromuscular synapses (NMJ) are shown as whereas dendritic processes where synaptic inputs are received are shown as .
Class A axons run forward in both
cords (VNC and DC) whereas the class B axons run backwards. The dendritic branches
of the dorsal and ventral class A neurons run in opposite directions as do those
from class Bneurons. Ventral class D neurons receive their synaptic input on
the dorsal side and give NMJ's on the ventral side. The dorsal type D neurons
have half the periodicity of their ventral counterparts and receive synapses
on the ventral side and give NMJ's on the dorsal side. Class AS neurons only
synapse on the dorsal side and have no ventral counterpart, whereas, the class
C neurons only synapse on the ventral side. The synapses from class C motor
neurons onto body muscles are less dense than for the other classes (White
J. et al, 1976.)
Synaptic map and process positioning of the VNC motor neurons (from White
J. et al, 1976):
Connections of each motor neuron class
Motor neuron class |
Chemical synapses to other motor neurons |
Chemical synapses from |
Gap junctions |
AS |
DA, DD, VD |
AVA, AVB, AVD, AVE |
DA, VA, AVA |
DA |
DB, DD, VD |
AVA, AVD, AVE, HSNR, PVCL, SABVL |
AS, VA, AVA |
DB |
AS, DD, VD |
DVA, PVC, PVR |
DB, VB, AVB |
DD |
VD |
RID, VC1-3 |
DD, VD |
VA* |
DD, VA, VB, VD |
AVA, AVB, AVD, AVE |
AS, DA, AVA, SABD |
VB* |
DD, VA, VD |
PVC |
VB, DB, AVB |
VD |
VA, VB |
AVEL, PVNR, VC1-3 |
DD, VA, VD, PVPR |
(Based on the Mind of a Worm and Haspel & Donovan 2011; *VA1,3,5 and VB1,4,7 have slightly different connections than the remainder of the class) |
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