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.





 


Click image for closeup view 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
DA and DB Neurons
Dosal DA and DB neurons
VA Neurons
VA neurons
VB Neurons
VB neurons
VC Neurons
VC neurons
DD and VD Neurons
DD VD neurons

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)
image