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Light and pheromone-sensing neurons regulates cold habituation through insulin signalling in Caenorhabditis elegans.

Ohta A, Ujisawa T, Sonoda S, Kuhara A - Nat Commun (2014)

Bottom Line: However, how animals habituate to temperature is poorly understood.Calcium imaging reveals that ASJ neurons respond to temperature.Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

View Article: PubMed Central - PubMed

Affiliation: 1] Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, Institute for Integrative Neurobiology, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan [2].

ABSTRACT
Temperature is a critical environmental stimulus that has a strong impact on an organism's biochemistry. Animals can respond to changes in ambient temperature through behaviour or altered physiology. However, how animals habituate to temperature is poorly understood. The nematode C. elegans stores temperature experiences and can induce temperature habituation-linked cold tolerance. Here we show that light and pheromone-sensing neurons (ASJ) regulate cold habituation through insulin signalling. Calcium imaging reveals that ASJ neurons respond to temperature. Cold habituation is abnormal in a mutant with impaired cGMP signalling in ASJ neurons. Insulin released from ASJ neurons is received by the intestine and neurons regulating gene expression for cold habituation. Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

No MeSH data available.


Related in: MedlinePlus

Neural activity of ASJ sensory neuron with temperature stimuli.(a) Wild type and mutant expressing yellow cameleon driven by trx-1 promoter, trx-1p::yc3.60 (pTOM13), were tested by calcium imaging. Representative fluorescence resonance energy transfer signal in ASJ of wild type or tax-4 mutant cultivated at 15 °C when worms were subjected to temperature changes. A schematic diagram of an ASJ in head, and corresponding pseudo colour images depicting fluorescence ratio of cameleon before and during temperature change. Arrows, indicate ASJ cell body. Scale bar, 10 μm. (b,c,f) In vivo calcium imaging of ASJ from wild type cultivated at each temperature (b), mutants (c,f). Relative increase or decrease in the intracellular Ca2+ concentration was measured as an increase or decrease in yellow fluorescent protein/cyan fluorescent proteins fluorescence ratio of the cameleon (ratio change) during temperature changes. Temperature changes (ranging from 17–23 °C) with time are shown at the bottom of the graph. Calcium concentrations in ASJ of wild type change following temperature stimuli, which were observed in animals cultivated at different temperatures (b). Calcium concentration changes responding to temperature shifts were not observed in tax-4(p678) (c). lite-1 and tax-4; Ex[trx-1p::tax-4], which is a tax-4 mutant with specifically expressing tax-4 cDNA in ASJ, could respond to temperature changes (c). snb-1 (md247) mutants also responded (f). Each graph represents average response to temperature stimuli (b,c,f). n=12–17. (d) Bar graph showing average ratio change during 20 s from 120 to 140 s of the experiment indicated in (c). Colour key for bar graph is the same as that for the corresponding response curve in (c). (e) Calcium imaging of ASJ in wild type during longer times. At 30 min after temperature shift, intracellular Ca2+ concentration in ASJ was at its maximum, after which a decrease was observed and stabilized. Fluorescence ratio was measured at −1, 0, 30, 60, 120, 180, 240 and 300 min after temperature change. At each time point, fluorescence signal of cameleon was detected for 60 s. Two Scale bars, −1 to 0 min and 0 to 300 min, are shown on the horizontal line. The data were sequentially measured in chronological order using individual animals. n=13. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. **P<0.01.
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f3: Neural activity of ASJ sensory neuron with temperature stimuli.(a) Wild type and mutant expressing yellow cameleon driven by trx-1 promoter, trx-1p::yc3.60 (pTOM13), were tested by calcium imaging. Representative fluorescence resonance energy transfer signal in ASJ of wild type or tax-4 mutant cultivated at 15 °C when worms were subjected to temperature changes. A schematic diagram of an ASJ in head, and corresponding pseudo colour images depicting fluorescence ratio of cameleon before and during temperature change. Arrows, indicate ASJ cell body. Scale bar, 10 μm. (b,c,f) In vivo calcium imaging of ASJ from wild type cultivated at each temperature (b), mutants (c,f). Relative increase or decrease in the intracellular Ca2+ concentration was measured as an increase or decrease in yellow fluorescent protein/cyan fluorescent proteins fluorescence ratio of the cameleon (ratio change) during temperature changes. Temperature changes (ranging from 17–23 °C) with time are shown at the bottom of the graph. Calcium concentrations in ASJ of wild type change following temperature stimuli, which were observed in animals cultivated at different temperatures (b). Calcium concentration changes responding to temperature shifts were not observed in tax-4(p678) (c). lite-1 and tax-4; Ex[trx-1p::tax-4], which is a tax-4 mutant with specifically expressing tax-4 cDNA in ASJ, could respond to temperature changes (c). snb-1 (md247) mutants also responded (f). Each graph represents average response to temperature stimuli (b,c,f). n=12–17. (d) Bar graph showing average ratio change during 20 s from 120 to 140 s of the experiment indicated in (c). Colour key for bar graph is the same as that for the corresponding response curve in (c). (e) Calcium imaging of ASJ in wild type during longer times. At 30 min after temperature shift, intracellular Ca2+ concentration in ASJ was at its maximum, after which a decrease was observed and stabilized. Fluorescence ratio was measured at −1, 0, 30, 60, 120, 180, 240 and 300 min after temperature change. At each time point, fluorescence signal of cameleon was detected for 60 s. Two Scale bars, −1 to 0 min and 0 to 300 min, are shown on the horizontal line. The data were sequentially measured in chronological order using individual animals. n=13. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. **P<0.01.

Mentions: We hypothesized that ASJ neurons act as thermosensory neurons. To examine this hypothesis, we used the genetically encoded calcium indicator, cameleon1617, to perform calcium imaging of the ASJ neuron under temperature changes. The cameleon gene, yc3.60, was expressed in ASJ sensory neurons under the trx-1 promoter. We found that the calcium concentration in ASJ neurons changes in response to temperature (Fig. 3a,b; Supplementary Fig. 2c,d). By contrast, this temperature response was decreased in the tax-4 mutant, which lacks a cGMP-gated channel essential for sensory signalling in ASJ (Fig. 3c,d). The defect in tax-4 mutants was rescued by specific expression of tax-4 cDNA in ASJ neurons, even in the absence of expression in the sensory neurons that regulate thermotaxis, such as AFD, AWC and ASI (Fig. 3c,d). Thus, physiological and genetic analyses suggest that ASJ acts as a temperature-sensing neuron. Moreover, the temperature response of ASJ was normal in the mutant with impaired SNB-1/synaptobrevin (Fig. 3f), suggesting that ASJ responses to temperature changes are cell autonomous and do not require neurochemical input from other neurons.


Light and pheromone-sensing neurons regulates cold habituation through insulin signalling in Caenorhabditis elegans.

Ohta A, Ujisawa T, Sonoda S, Kuhara A - Nat Commun (2014)

Neural activity of ASJ sensory neuron with temperature stimuli.(a) Wild type and mutant expressing yellow cameleon driven by trx-1 promoter, trx-1p::yc3.60 (pTOM13), were tested by calcium imaging. Representative fluorescence resonance energy transfer signal in ASJ of wild type or tax-4 mutant cultivated at 15 °C when worms were subjected to temperature changes. A schematic diagram of an ASJ in head, and corresponding pseudo colour images depicting fluorescence ratio of cameleon before and during temperature change. Arrows, indicate ASJ cell body. Scale bar, 10 μm. (b,c,f) In vivo calcium imaging of ASJ from wild type cultivated at each temperature (b), mutants (c,f). Relative increase or decrease in the intracellular Ca2+ concentration was measured as an increase or decrease in yellow fluorescent protein/cyan fluorescent proteins fluorescence ratio of the cameleon (ratio change) during temperature changes. Temperature changes (ranging from 17–23 °C) with time are shown at the bottom of the graph. Calcium concentrations in ASJ of wild type change following temperature stimuli, which were observed in animals cultivated at different temperatures (b). Calcium concentration changes responding to temperature shifts were not observed in tax-4(p678) (c). lite-1 and tax-4; Ex[trx-1p::tax-4], which is a tax-4 mutant with specifically expressing tax-4 cDNA in ASJ, could respond to temperature changes (c). snb-1 (md247) mutants also responded (f). Each graph represents average response to temperature stimuli (b,c,f). n=12–17. (d) Bar graph showing average ratio change during 20 s from 120 to 140 s of the experiment indicated in (c). Colour key for bar graph is the same as that for the corresponding response curve in (c). (e) Calcium imaging of ASJ in wild type during longer times. At 30 min after temperature shift, intracellular Ca2+ concentration in ASJ was at its maximum, after which a decrease was observed and stabilized. Fluorescence ratio was measured at −1, 0, 30, 60, 120, 180, 240 and 300 min after temperature change. At each time point, fluorescence signal of cameleon was detected for 60 s. Two Scale bars, −1 to 0 min and 0 to 300 min, are shown on the horizontal line. The data were sequentially measured in chronological order using individual animals. n=13. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. **P<0.01.
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Related In: Results  -  Collection

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f3: Neural activity of ASJ sensory neuron with temperature stimuli.(a) Wild type and mutant expressing yellow cameleon driven by trx-1 promoter, trx-1p::yc3.60 (pTOM13), were tested by calcium imaging. Representative fluorescence resonance energy transfer signal in ASJ of wild type or tax-4 mutant cultivated at 15 °C when worms were subjected to temperature changes. A schematic diagram of an ASJ in head, and corresponding pseudo colour images depicting fluorescence ratio of cameleon before and during temperature change. Arrows, indicate ASJ cell body. Scale bar, 10 μm. (b,c,f) In vivo calcium imaging of ASJ from wild type cultivated at each temperature (b), mutants (c,f). Relative increase or decrease in the intracellular Ca2+ concentration was measured as an increase or decrease in yellow fluorescent protein/cyan fluorescent proteins fluorescence ratio of the cameleon (ratio change) during temperature changes. Temperature changes (ranging from 17–23 °C) with time are shown at the bottom of the graph. Calcium concentrations in ASJ of wild type change following temperature stimuli, which were observed in animals cultivated at different temperatures (b). Calcium concentration changes responding to temperature shifts were not observed in tax-4(p678) (c). lite-1 and tax-4; Ex[trx-1p::tax-4], which is a tax-4 mutant with specifically expressing tax-4 cDNA in ASJ, could respond to temperature changes (c). snb-1 (md247) mutants also responded (f). Each graph represents average response to temperature stimuli (b,c,f). n=12–17. (d) Bar graph showing average ratio change during 20 s from 120 to 140 s of the experiment indicated in (c). Colour key for bar graph is the same as that for the corresponding response curve in (c). (e) Calcium imaging of ASJ in wild type during longer times. At 30 min after temperature shift, intracellular Ca2+ concentration in ASJ was at its maximum, after which a decrease was observed and stabilized. Fluorescence ratio was measured at −1, 0, 30, 60, 120, 180, 240 and 300 min after temperature change. At each time point, fluorescence signal of cameleon was detected for 60 s. Two Scale bars, −1 to 0 min and 0 to 300 min, are shown on the horizontal line. The data were sequentially measured in chronological order using individual animals. n=13. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. **P<0.01.
Mentions: We hypothesized that ASJ neurons act as thermosensory neurons. To examine this hypothesis, we used the genetically encoded calcium indicator, cameleon1617, to perform calcium imaging of the ASJ neuron under temperature changes. The cameleon gene, yc3.60, was expressed in ASJ sensory neurons under the trx-1 promoter. We found that the calcium concentration in ASJ neurons changes in response to temperature (Fig. 3a,b; Supplementary Fig. 2c,d). By contrast, this temperature response was decreased in the tax-4 mutant, which lacks a cGMP-gated channel essential for sensory signalling in ASJ (Fig. 3c,d). The defect in tax-4 mutants was rescued by specific expression of tax-4 cDNA in ASJ neurons, even in the absence of expression in the sensory neurons that regulate thermotaxis, such as AFD, AWC and ASI (Fig. 3c,d). Thus, physiological and genetic analyses suggest that ASJ acts as a temperature-sensing neuron. Moreover, the temperature response of ASJ was normal in the mutant with impaired SNB-1/synaptobrevin (Fig. 3f), suggesting that ASJ responses to temperature changes are cell autonomous and do not require neurochemical input from other neurons.

Bottom Line: However, how animals habituate to temperature is poorly understood.Calcium imaging reveals that ASJ neurons respond to temperature.Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

View Article: PubMed Central - PubMed

Affiliation: 1] Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, Institute for Integrative Neurobiology, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan [2].

ABSTRACT
Temperature is a critical environmental stimulus that has a strong impact on an organism's biochemistry. Animals can respond to changes in ambient temperature through behaviour or altered physiology. However, how animals habituate to temperature is poorly understood. The nematode C. elegans stores temperature experiences and can induce temperature habituation-linked cold tolerance. Here we show that light and pheromone-sensing neurons (ASJ) regulate cold habituation through insulin signalling. Calcium imaging reveals that ASJ neurons respond to temperature. Cold habituation is abnormal in a mutant with impaired cGMP signalling in ASJ neurons. Insulin released from ASJ neurons is received by the intestine and neurons regulating gene expression for cold habituation. Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

No MeSH data available.


Related in: MedlinePlus