Type:Sensory neuron (oxygen- and carbondioxide-sensory In MoW:BAG Male Wiring Project:BAGL, BAGR In Wormbase:BAG, BAGL, BAGR Lineage:AB alppappap, AB arappppap Location:Anterior to the nerve ring in head Description:Have ciliated endings in head, not part of a sensillum. The endings are not open to outside. Neurotransmitter/ Neuropeptide:
- Glutamate
- NLP-3; neuropeptide-like protein (Nathoo et al., 2001; O. Hobert, pers.comm.) Innexin expression:
- INX-19 (Chuang et al, 2007) Receptor expression:
- GCY-33; orphan receptor (chemosensory/ odorant?) guanylyl cyclase (Yu et al., 1997). Function:
-A neural circuit that includes BAG neurons mediate acute CO2 avoidance (Hallem and Sternberg, 2008; Bretscher et al., 2008)
- O2 sensation mainly requires the opposing actions of BAG and URX sensory neurons. URX affects behaviors similarly in well-fed or starved animals, while BAG is more important in starved animals. In wild type animals with high NPR-1 function, BAG neurons sense decreases in O2
concentrations and lead to transient slowing behavior, while URX neurons sense elevations. The interaction of these neurons results in locomotion responses allowing the worm to find and settle at places of preferred O2 concentrations. The O2-sensing abilities of BAG and URX neurons are attributed to specific O2-binding soluble guanylate cyclases (sGCs) within those neuron classes; GCY-31 and GCY-33 in BAG neurons, and GCY-35 and GCY-36 in URX neurons (Skora and Zimmer, 2013; Zimmer et al, 2009).
- Lifespan regulation; ablation of low-O2-sensing BAG neurons increases lifespan, while ablation of high-O2-sensing URX neurons decreases lifespan. BAG and URX neurons counterbalance each other for control of lifespan via functions of different sCGs. Also, their life-span modulating effects are independent of canonical life-span modulatory pathways, including DAF-2/DAF-16, DAF-12, germline signaling, sensory perception pathways or dietary restriction (Liu and Cai; 2013)
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BAGL (AB alppappap) development in the embryo. Dorsal view. Bottom is left side of the embryo. Spheres indicate individual nuclei. Black sphere: ancestors of BAGL; 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).
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BAGR (AB arappppap) development in the embryo. Dorsal view. Bottom is left side of the embryo. Spheres indicate individual nuclei. Black sphere: ancestors of BAGR; 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).
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3D reconstruction of the anterior sensory endings (cilia and dendrites) from high resolution serial section transmission electron micrographs. Bar 1 μm. Color code for the sensory endings is shown on the right-colors do not follow the WA color code. To expand, double click on the video, to return to original size, click "esc" (Doroquez et al., 2014)
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3D reconstruction of all amphid neuron cilia and associated socket and sheath cell processes. Modeled from serial section transmission electron micrographs (ssTEMs). Bar 1 μm. Color code for the sensory endings is shown on the left-colors do not follow the WA color code. To expand, double click on the video, to return to original size, click "esc" (Doroquez et al., 2014)
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3D reconstruction of BAG and FLP cilia.
Both cilia are shown as associated with ILso process. Colors do not follow the WA color code (purple; BAG cilia, green; FLP cilia and dendritic endings, beige: ILso), ssTEM; serial section transmission electron micrography, TZ: transition zone. To expand, double click on the video, to return to original size, click "esc" (Doroquez et al., 2014)
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