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A gap junction circuit enhances processing of coincident mechanosensory inputs.

Rabinowitch I, Chatzigeorgiou M, Schafer WR - Curr. Biol. (2013)

Bottom Line: Modeling approaches have been useful for understanding structurally and dynamically more complex electrical circuits.Therefore, we formulated a simple analytical model with minimal assumptions to obtain insight into the properties of the hub-and-spoke microcircuit motif.Thus, the hub-and-spoke architecture may implement an analog coincidence detector enabling distinct responses to distributed and localized patterns of sensory input.

View Article: PubMed Central - PubMed

Affiliation: Cell Biology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.

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The C. elegans Nose Touch Hub-and-Spoke CircuitThe nose touch circuit consists of three spoke sensory neuron classes (FLP, OLQ, and CEP) and a hub interneuron (RIH). Distinct proteins required for mechanosensation in each spoke are indicated. Dotted lines represent gap junctions; continuous lines represent chemical synapses.
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fig2: The C. elegans Nose Touch Hub-and-Spoke CircuitThe nose touch circuit consists of three spoke sensory neuron classes (FLP, OLQ, and CEP) and a hub interneuron (RIH). Distinct proteins required for mechanosensation in each spoke are indicated. Dotted lines represent gap junctions; continuous lines represent chemical synapses.

Mentions: To test this prediction, we examined the effect of an inactive input on the C. elegans nose touch circuit by either silencing a spoke neuron class or ablating it (Figures 2 and 3). In this circuit, three classes of nose touch mechanosensory neurons—two FLPs, four OLQs, and four CEPs—make gap junctions with a single hub, the RIH interneuron (Figure 2). We showed previously [9] that active mechanoreceptors facilitate the responses of other sensory neurons in the network to low-threshold stimuli through gap-junction-mediated lateral facilitation. Nose touch stimulation evokes transient calcium increases in all the sensory neurons, as well as a more sustained calcium transient in RIH. Distinct gene products are required cell autonomously in each mechanoreceptor neuron class for sensing touch (Figure 2): the DEG/ENaC channel MEC-10 in the FLPs [9, 13], the TRPV channel OSM-9 in the OLQs [9, 14], and the TRPN channel TRP-4 in the CEPs [15–17]. We thus imaged nose touch responses in animals with either sensory transduction mutations (mec-10, osm-9, or trp-4) that inactivate or ablations that eliminate the same spoke neurons (Figure 3).


A gap junction circuit enhances processing of coincident mechanosensory inputs.

Rabinowitch I, Chatzigeorgiou M, Schafer WR - Curr. Biol. (2013)

The C. elegans Nose Touch Hub-and-Spoke CircuitThe nose touch circuit consists of three spoke sensory neuron classes (FLP, OLQ, and CEP) and a hub interneuron (RIH). Distinct proteins required for mechanosensation in each spoke are indicated. Dotted lines represent gap junctions; continuous lines represent chemical synapses.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675673&req=5

fig2: The C. elegans Nose Touch Hub-and-Spoke CircuitThe nose touch circuit consists of three spoke sensory neuron classes (FLP, OLQ, and CEP) and a hub interneuron (RIH). Distinct proteins required for mechanosensation in each spoke are indicated. Dotted lines represent gap junctions; continuous lines represent chemical synapses.
Mentions: To test this prediction, we examined the effect of an inactive input on the C. elegans nose touch circuit by either silencing a spoke neuron class or ablating it (Figures 2 and 3). In this circuit, three classes of nose touch mechanosensory neurons—two FLPs, four OLQs, and four CEPs—make gap junctions with a single hub, the RIH interneuron (Figure 2). We showed previously [9] that active mechanoreceptors facilitate the responses of other sensory neurons in the network to low-threshold stimuli through gap-junction-mediated lateral facilitation. Nose touch stimulation evokes transient calcium increases in all the sensory neurons, as well as a more sustained calcium transient in RIH. Distinct gene products are required cell autonomously in each mechanoreceptor neuron class for sensing touch (Figure 2): the DEG/ENaC channel MEC-10 in the FLPs [9, 13], the TRPV channel OSM-9 in the OLQs [9, 14], and the TRPN channel TRP-4 in the CEPs [15–17]. We thus imaged nose touch responses in animals with either sensory transduction mutations (mec-10, osm-9, or trp-4) that inactivate or ablations that eliminate the same spoke neurons (Figure 3).

Bottom Line: Modeling approaches have been useful for understanding structurally and dynamically more complex electrical circuits.Therefore, we formulated a simple analytical model with minimal assumptions to obtain insight into the properties of the hub-and-spoke microcircuit motif.Thus, the hub-and-spoke architecture may implement an analog coincidence detector enabling distinct responses to distributed and localized patterns of sensory input.

View Article: PubMed Central - PubMed

Affiliation: Cell Biology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.

Show MeSH