AVAL, AVAR

Type: Interneuron
In MoW: AVA
Male Wiring Project: AVALh, AVARh, AVALm, AVARm
In Wormbase: AVA, AVAL, AVAR
Lineage: AB alppaaapa, AB alaappapa
Location: Lateral ganglia of head
Description:
One of four bilaterally symmetric interneuron pairs (AVA, AVB, AVD, and PVC) with large-diameter axons that run the entire length of the ventral nerve cord and provide input to the ventral cord motor neurons. Synapse onto A-type (VA, DA) and AS motor neurons. Formerly called alpha. In males, AVAL receives input from PQR, PVY and PVX (Jarrell et al., 2012)
Neurotransmitter/ Neuropeptide:
- Acetylcholine
- FLP-1; FMRFamide-like peptide
- FLP-18; FMRFamide-related neuropeptide
(Although earlier reports suggested AVA might be glutamatergic, more recent studies showed it is not)
(Pereira et al., 2015; Serrano-Saiz et al., 2013; Ohnishi et al., 2011; Rogers et al., 2003; Nelson et al., 1998)

Innexin expression:
- INX-7
- UNC-7
- UNC-9
(Altun et al., 2009)
Receptor expression:
- Possibly GGR-3 ; GABA-A/glycine receptor-like protein
- GLR-1; glutamate receptor subunit
- GLR-2; glutamate receptor subunit
- GLR-4; glutamate receptor subunit
- GLR-5; glutamate receptor subunit
- NMR-1; glutamate receptor subunit
- NMR-2; glutamate receptor subunit




- UNC-8, a DEG/ENaC family member homologous to subunits of a candidate mechanically-gated, cation-specific ion channel
(Wormbase; Altun, 2011; Brockie et al., 2001; Tavernarakis et al., 1997; Fujiwara et al., 1996; Maricq et al., 1995)
Function: Command interneuron.
- Locomotion; functions as driver cell for backward locomotion (reversal). Drives backward movement of the animal along with touch modulator AVD neuron, AVE and A-type motor neurons. However, although AVA/AVD/AVE are important for initiating reversals, they are not essential, since worms lacking these neurons can still initiate reversals although at a reduced frequency (Piggott et al., 2011)


 
 

Click here for larger version
AVAL (AB alppaaapa) development in the embryo.
Dorsal view. Bottom is left side of the embryo. Spheres indicate individual nuclei. Black sphere: ancestors of AVAL; dark grey spheres: apoptotic cells; other cells follow the WA color code (after they acquire specific cell or tissue identities). 0 min is fertilization. Click on the movie for higher resolution rendition (by A. Santella & Z. Bao).

 
 

Click here for larger version
AVAR (AB alaappapa) development in the embryo.
Dorsal view. Bottom is left side of the embryo. Spheres indicate individual nuclei. Black sphere: ancestors of AVAR; dark grey spheres: apoptotic cells; other cells follow the WA color code (after they acquire specific cell or tissue identities). 0 min is fertilization. Click on the movie for higher resolution rendition (by A. Santella & Z. Bao).

image