scholarly journals C. elegans AWA Olfactory Neurons Fire Calcium-Mediated All-or-None Action Potentials

Cell ◽  
2018 ◽  
Vol 175 (1) ◽  
pp. 57-70.e17 ◽  
Author(s):  
Qiang Liu ◽  
Philip B. Kidd ◽  
May Dobosiewicz ◽  
Cornelia I. Bargmann
Keyword(s):  
Action Potentials ◽  
Olfactory Neurons ◽  
C Elegans

scholarly journals The C.elegans AWA Olfactory Neuron Fires Calcium-Mediated All-or-None Action Potentials

2018 ◽  
Author(s):  
Qiang Liu ◽  
Philip B. Kidd ◽  
May Dobosiewicz ◽  
Cornelia I. Bargmann
Keyword(s):  
Calcium Imaging ◽  
Action Potentials ◽  
Neural Coding ◽  
Patch Clamp Recording ◽  
Olfactory Neurons ◽  
C Elegans ◽  
Coding Schemes ◽  
Current Voltage ◽  
Ion Substitution ◽  
Specialized Function

SummaryWe find, unexpectedly, that C. elegans neurons can encode information through regenerative all-or-none action potentials. In a survey of current-voltage relationships in C. elegans neurons, we discovered that AWA olfactory neurons generate membrane potential spikes with defining characteristics of action potentials. Ion substitution experiments, pharmacology, and mutant analysis identified a voltage-gated CaV1 calcium channel and a Shaker-type potassium channel that underlie action potential dynamics in AWA. Simultaneous patch-clamp recording and calcium imaging in AWA revealed spike-associated calcium signals that were also observed after odor stimulation of intact animals, suggesting that natural odor stimuli induce AWA action potentials. The stimulus regimes that elicited action potentials match AWA’s proposed specialized function in climbing odor gradients. Our results provide evidence that C. elegans can use digital as well as analog coding schemes, expand the computational repertoire of its nervous system, and inform future modeling of its neural coding and network dynamics.

The Caenorhabditis elegans odr-2 Gene Encodes a Novel Ly-6-Related Protein Required for Olfaction

Genetics ◽  
2001 ◽  
Vol 157 (1) ◽  
pp. 211-224 ◽  
Author(s):  
Joseph H Chou ◽  
Cornelia I Bargmann ◽  
Piali Sengupta
Keyword(s):  
Caenorhabditis Elegans ◽  
Motor Neurons ◽  
Amino Terminus ◽  
Signaling Proteins ◽  
Related Protein ◽  
Olfactory Neurons ◽  
Unique Role ◽  
C Elegans ◽  
Founding Member ◽  
High Concentrations

Abstract Caenorhabditis elegans odr-2 mutants are defective in the ability to chemotax to odorants that are recognized by the two AWC olfactory neurons. Like many other olfactory mutants, they retain responses to high concentrations of AWC-sensed odors; we show here that these residual responses are caused by the ability of other olfactory neurons (the AWA neurons) to be recruited at high odor concentrations. odr-2 encodes a membrane-associated protein related to the Ly-6 superfamily of GPI-linked signaling proteins and is the founding member of a C. elegans gene family with at least seven other members. Alternative splicing of odr-2 yields three predicted proteins that differ only at the extreme amino terminus. The three isoforms have different promoters, and one isoform may have a unique role in olfaction. An epitope-tagged ODR-2 protein is expressed at high levels in sensory neurons, motor neurons, and interneurons and is enriched in axons. The AWC neurons are superficially normal in their development and structure in odr-2 mutants, but their function is impaired. Our results suggest that ODR-2 may regulate AWC signaling within the neuronal network required for chemotaxis.

scholarly journals The quest for action potentials in C. elegans neurons hits a plateau

2009 ◽  
Vol 12 (4) ◽  
pp. 377-378 ◽  
Author(s):  
Shawn R Lockery ◽  
Miriam B Goodman
Keyword(s):  
Action Potentials ◽  
C Elegans

scholarly journals The Gα Protein ODR-3 Mediates Olfactory and Nociceptive Function and Controls Cilium Morphogenesis in C. elegans Olfactory Neurons

Neuron ◽  
1998 ◽  
Vol 20 (1) ◽  
pp. 55-67 ◽  
Author(s):  
Kayvan Roayaie ◽  
Justin Gage Crump ◽  
Alvaro Sagasti ◽  
Cornelia I Bargmann
Keyword(s):  
Olfactory Neurons ◽  
C Elegans

scholarly journals Reply to “First report of action potentials in a C. elegans neuron is premature”

2009 ◽  
Vol 12 (4) ◽  
pp. 366-366 ◽  
Author(s):  
Jerry E Mellem ◽  
Penelope J Brockie ◽  
David M Madsen ◽  
Andres V Maricq
Keyword(s):  
Action Potentials ◽  
First Report ◽  
C Elegans

scholarly journals Odor Sensitivity as a Biomarker of Aging

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 121-122
Author(s):  
Marjana Sarker ◽  
Scott Leiser
Keyword(s):  
Olfactory System ◽  
Healthy Adult ◽  
Model Organism ◽  
Olfactory Neurons ◽  
Adult Lifespan ◽  
C Elegans ◽  
Short Lifespan ◽  
Age Related ◽  
Odor Sensitivity ◽  
Biomarker Of Aging

Abstract Recent studies support the deterioration of the sense of smell as an important biomarker for cognitive impairment diseases, including Alzheimer’s disease. The model organism C. elegans has a well-studied olfactory system, which provides an ideal platform to measure loss of smell with aging. The goal of our project is to use the short lifespan and olfactory changes observed in nematodes to identify mechanisms to slow aging and treat age-related diseases. Our approach is to utilize worms at various times of their healthy adult lifespan and to test for their sensitivity to known attractants such as benzaldehyde. These odorants are largely detected by the main AWC olfactory neurons. It is well documented that the responsiveness of AWC decreases with age. Our paradigm is to briefly fast worms to increase motivation before testing their ability to discriminate odors. Our results show that younger worms actively move toward the attractant and show preference for specific attractants. However, older worms frequently do not respond to attractive odors and remain near the point of origin, regardless of motility. These results indicate a decreased odor response with age. Our current work focuses on identifying genes and compounds that positively affect this odor response in older animals. The resulting data can then be tested for their efficacy to improve other aspects of healthspan and potentially longevity.

scholarly journals Voltage-dependent and odorant-regulated currents in isolated olfactory receptor neurons of the channel catfish.

1992 ◽  
Vol 99 (4) ◽  
pp. 505-529 ◽  
Author(s):  
T Miyamoto ◽  
D Restrepo ◽  
J H Teeter
Keyword(s):  
Action Potentials ◽  
Olfactory Receptor Neurons ◽  
Olfactory Neurons ◽  
Outward Currents ◽  
Na Currents ◽  
Voltage Dependent ◽  
Inward Currents ◽  
K Current ◽  
Receptor Neurons ◽  
K Currents

The electrical properties of olfactory receptor neurons, enzymatically dissociated from the channel catfish (Ictalurus punctatus), were studied using the whole-cell patch-clamp technique. Six voltage-dependent ionic currents were isolated. Transient inward currents (0.1-1.7 nA) were observed in response to depolarizing voltage steps from a holding potential of -80 mV in all neurons examined. They activated between -70 and -50 mV and were blocked by addition of 1 microM tetrodotoxin (TTX) to the bath or by replacing Na+ in the bath with N-methyl-D-glucamine and were classified as Na+ currents. Sustained inward currents, observed in most neurons examined when Na+ inward currents were blocked with TTX and outward currents were blocked by replacing K+ in the pipette solution with Cs+ and by addition of 10 mM Ba2+ to the bath, activated between -40 and -30 mV, reached a peak at 0 mV, and were blocked by 5 microM nimodipine. These currents were classified as L-type Ca2+ currents. Large, slowly activating outward currents that were blocked by simultaneous replacement of K+ in the pipette with Cs+ and addition of Ba2+ to the bath were observed in all olfactory neurons examined. The outward K+ currents activated over approximately the same range as the Na+ currents (-60 to -50 mV), but the Na+ currents were larger at the normal resting potential of the neurons (-45 +/- 11 mV, mean +/- SD, n = 52). Four different types of K+ currents could be differentiated: a Ca(2+)-activated K+ current, a transient K+ current, a delayed rectifier K+ current, and an inward rectifier K+ current. Spontaneous action potentials of varying amplitude were sometimes observed in the cell-attached recording configuration. Action potentials were not observed in whole-cell recordings with normal internal solution (K+ = 100 mM) in the pipette, but frequently appeared when K+ was reduced to 85 mM. These observations suggest that the membrane potential and action potential amplitude of catfish olfactory neurons are significantly affected by the activity of single channels due to the high input resistance (6.6 +/- 5.2 G omega, n = 20) and low membrane capacitance (2.1 +/- 1.1 pF, n = 46) of the cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals First report of action potentials in a C. elegans neuron is premature

2009 ◽  
Vol 12 (4) ◽  
pp. 365-366 ◽  
Author(s):  
Shawn R Lockery ◽  
Miriam B Goodman ◽  
Serge Faumont
Keyword(s):  
Action Potentials ◽  
First Report ◽  
C Elegans

scholarly journals Action potentials contribute to neuronal signaling in C. elegans

2008 ◽  
Vol 11 (8) ◽  
pp. 865-867 ◽  
Author(s):  
Jerry E Mellem ◽  
Penelope J Brockie ◽  
David M Madsen ◽  
Andres V Maricq
Keyword(s):  
Action Potentials ◽  
Neuronal Signaling ◽  
C Elegans
Sign in / Sign up

Export Citation Format

Share Document